Dr Matthew Bultitude: So everyone would be advised to have a low salt diet. I think in our diet sheet at guys we say six grams a day. I think some say less than three grams a day, but the principle is salt is bad for the body, bad for blood pressure, bad as you say for other cardiovascular risk factors. So, you know, I think everybody should be trying to follow a low salt diet. And there can be a lot of sneaky salt in diets, can't there?
Dr Rupy: Welcome to the Doctor's Kitchen podcast. The show about food, lifestyle, medicine and how to improve your health today. I'm Dr Rupy, your host. I'm a medical doctor, I study nutrition and I'm a firm believer in the power of food and lifestyle as medicine. Join me and my expert guests while we discuss the multiple determinants of what allows you to lead your best life.
Dr Rupy: Today I have not one, but two urology consultants on the podcast, Dr Nish Bedy, who some of you may remember from the podcast we recorded a couple of years ago now, titled Eat For Your Bladder, and Dr Matthew Bultitude, a surgeon at Guy's and St Thomas's Hospital in London. Today we are talking all things kidney stones, a topic requested by a number of followers and colleagues who asked for advice on this via social media and my newsletter feedback form. Yes, I read all the feedback on the doctorskitchen.com newsletter that you can sign up to, the doctorskitchen.com. Today, we're going to talk about what types of stones there are and the impact of hydration, sugar, animal protein, salt and fibre on the propensity toward stones. How we prevent them, what things one should include or exclude depending on their condition, supplements for stones, as well as acidification and alkalinisation of the urine and what that means clinically. This is a fascinating discussion and one that you can also watch on YouTube. You can watch it on the Doctor's Kitchen channel. I sat down with both Matthew and Nish on a sofa in front of cameras. It was a, it was a right laugh. Please do share this information widely as I'm sure it will be absolutely helpful and game changing for many people out there, especially considering that 10% of the population will suffer with a kidney stone over their lifetime. As an introduction, Dr Matthew Bultitude is a consultant urological surgeon at Guy's and St Thomas's Hospital in London. He is a general urologist and has a special interest in kidney stone disease. He has an interest in metabolic stones, in particular the rare condition called cystinuria, which predisposes to lifelong kidney stones. He runs a rare disease website for patients with this condition. It's called cystinuriauk.co.uk, the link to which is in the show notes. At Guy's, he's been the clinical lead for his department and is currently the clinical director for transplantation, nephrology and urology. Dr Nish Bedy is a consultant urologist at Chelsea and Westminster Hospital, we're keeping it London today, and is passionate about bringing more specific dietary and lifestyle advice for certain urological conditions. This podcast is in a large part going to be because of him. He definitely was keen for this pod to happen, and he put everything together today. So really, really grateful for Nish. He's extensively published and regularly speaks at international conferences. There is also the Stone Away recipe book. This is a recipe book that is the brainchild of Matthew Bultitude and his colleagues at Guy's and St Thomas's. You can find the link to download that on the show notes at the doctorskitchen.com and in your the copy of whatever podcast player you're listening to this to. I do highly recommend you check that out. It's a very good practical recipe book. And if you're looking for recipes, don't look no further than the Doctor's Kitchen app. You can download that for free as well and get access to all of our recipes that are specifically tailored for health needs with new recipes added every single month. We have about 400 now. Do check out the Eat, Listen, Read newsletter. You can subscribe to that on the doctorskitchen.com website where I give you a recipe, some mindfully curated content, whether it be something to listen to, something to watch, something to read every single week. On to my chat with Matthew and Nish. Thanks so much for coming in today. I'm really excited to have you both here. Nish, we've known each other for a few years and you were telling me about this amazing conference that you went to or a presentation that you heard. So how do you know each other professionally?
Dr Nish Bedy: Well, yes, so on that conference presentation, that was Matt Bultitude was doing your, that was your presentation that you did at the RSM when you were asked to debunk, I think, stone supplements.
Dr Matthew Bultitude: Oh yeah.
Dr Nish Bedy: Which we may come on to before, but that's where I kind of first thought of this and when we met for a coffee and then discussed it from there really.
Dr Rupy: Yeah, yeah, yeah.
Dr Nish Bedy: But yeah, just because I thought that was interesting and it was, it was not like the typical kind of stone talk, I guess. It was more on supplements and diet and things. Yeah, so that was it. But I was just saying earlier that we met some, some 10 years ago now because I was running some conferences. It was called the Digital Doctor at that time. It's like health IT, something slightly different. And then you were doing your editor, the website for BJUI. And so they suggested when we approached them, they suggested you could come and talk to us because it was at that point you just gone digital from a paper journal.
Dr Matthew Bultitude: Yeah, that's right. We've done, I think we've done a few blogs together, haven't we? And done some blogs for different conferences and we obviously went to that conference and wrote that up for the BJUI. And then yeah, as you say, we recently I was invited to do this talk in America about supplements and kidney stones. And that's the talk I then gave at the Royal Society.
Dr Rupy: Yeah, yeah. And it's all pretty serendipitous because one of my best friends has got a stone or a current stone. And so he was asking me about diet. And then we just went for coffee and we just started talking about stones. So I thought, well, let's just do a podcast about it because I'm sure there are a lot of people who have actually who have got issues with kidney stones who would love to know a bit about diet and whether supplements are actually worth it because there's a lot of supplements on on the market, aren't there?
Dr Matthew Bultitude: There are, increasingly so. And I suspect it's very, very confusing for patients to know what is what is good and bad because everything is marketed as as, you know, being good in some way for kidney stones with very little evidence to back them up.
Dr Rupy: Yeah, yeah. And Matt, so you have a particular interest in this and you run one of the largest clinics in the world looking at a specific type of of kidney stone. Is that right?
Dr Matthew Bultitude: Yeah, that's right. So I I'm a specialist in kidney stones as a surgeon, but also in in terms of prevention. And so where I work at guys, we run a metabolic stone clinic specifically for this condition called cystinuria, which is a very rare condition. So most people listening to this podcast will not have if anyone will have cystinuria. It's less than one in 2,000 people have it. So but we have, yeah, the largest clinic in the world, I believe, looking at that condition, which is genetic. So people are predisposed to stone formation throughout their lives and often present in childhood with quite big stones.
Dr Rupy: Mm, yeah, yeah.
Dr Nish Bedy: I think it's, yeah, it's even rare for urologists. Like it's one of the things that we learn for the exam, but you know, I've not actually seen a patient with cystine stones. It's interesting that you have that clinic and it's kind of famous really for it.
Dr Rupy: Yeah, yeah. Well, I've got a general sort of overview of how I think this conversation should go, but I'm sure we're going to meander and go off course. So feel free to. But let's talk a bit about kidney stones, what they are. Actually, no, let's go back a little bit further. Let's talk about kidneys. Like, what why do we have kidneys? What's their what's their function and a little bit about the anatomy.
Dr Nish Bedy: So, I mean, in simple terms, I guess the kidneys filter your blood. That's the main things. They're also involved in a few hormone pathways in terms of maintaining regulation of different chemicals in your blood. Uh, anatomy wise, they're kind of under your ribs, but quite deep structures as well. Um, they're connected to your bladder by your ureters, which are sort of thin tubes going down to your bladder, which is where urine collects and then you you pee it out from there. It's a very basic overview.
Dr Matthew Bultitude: Yeah. So they filter the filter the blood, don't they? Get rid of all the waste, which comes out in the urine. But they also regulate, as you say, different hormones and regulate blood pressure as well. So they're they're vital for blood pressure regulation.
Dr Rupy: Absolutely. Yeah. And so when we when we're talking about kidney stones, what do we mean by kidney stones?
Dr Matthew Bultitude: Um, so I suppose, well, a stone is a um, a clump of crystals that form in the urine. So almost within the center of the kidney. So in the free part, which can often just sit up in the kidney for weeks, months, years, until at some point it decides to move and then drops down, blocks the the ureter, the pipe running down towards the bladder, which then causes what the pain that everyone associates with kidney stones, which is supposedly the worst pain imaginable when you have a block kidney.
Dr Rupy: Yeah.
Dr Nish Bedy: And I guess because urine looks colourless, you forget that it basically contains lots of these salts normally, like for most people, but it also contains things that sort of buffer stone formation as well. So there's a kind of balance between the two and most people that means that you don't then form stones. But obviously for people who do, there's an imbalance there, which, you know, could be for lots of reasons, including like genetic, which like the cystine stones that we're talking about earlier.
Dr Rupy: Yeah, yeah. We'll we'll get into some of the reasons as to why someone is predisposed to having stones. But let's give a sort of um an overview of like how prevalent kidney stones are. I'm sure if it's around one in 10 people in the UK, a lot of people listening to this are going to have experienced a stone or know someone who's experienced a stone. What what are the general sort of overview in terms of how prevalent this condition is?
Dr Matthew Bultitude: Yeah, so increasingly prevalent over the last few decades, probably linked with increasing obesity and Western diets. I often quote that figure of about one in lifetime risk of about one in 10. That's actually a figure for men. Um, women, it it traditionally has been rarer. But that gap is actually narrowing and that's that's sort of fast approaching, probably one in eight or something like that now. Um, because um, uh, yeah, I think because of the same sort of Western diets and and obesity.
Dr Rupy: Mm, yeah. It's interesting that because I I remember going to medical school, I wasn't really privy to it being a diet related issue or an obesity related issue. I think it was more the genetic components. I think similar vein to you learning about the specific rare crystals for the exams. That's sort of what I was thinking about when it comes to stones, but I don't think I I remember being taught about diet.
Dr Nish Bedy: Uh, I don't think we particularly covered diet either at medical school for stones or particularly for much, I guess other disease as well. I mean, there's so much you got to learn at that point. But um, I suppose that's why we're talking about it a bit today because the more you go into it, the more you you know, focus on that one area, then you learn about all of the surrounding things that impact it. And diet is one of those things that we do know a bit about for kidney stones.
Dr Rupy: Yeah.
Dr Matthew Bultitude: And we probably showing our age a bit now, aren't we? We've been a while since we're at medical school. And also the textbooks we use were older and they tend to focus on the pathological conditions that cause kidney stones and anatomical conditions that might cause kidney stones and won't focus on that.
Dr Rupy: Yeah, yeah. Um, so let's talk a bit about stones themselves. So you you you described them as a clump of crystals. How do we differentiate stones from each other? What are the commonest types?
Dr Matthew Bultitude: So by far and away the most common type is something called calcium oxalate. That makes up about 80% of of all stone types. So I think most people who've had one or two stones in their lifetime, it's a good guess that they will have had a calcium oxalate stone or predominantly calcium oxalate stone. Uh there are then rarer types of calcium phosphate is a distinct type, but often you get a mixture of stones. So quite a common thing we would see was that a stone is made 80% made of calcium oxalate, 20% made of calcium phosphate. And that may be the way that it's formed in the kidney that actually you get a bit of calcium phosphate and then you get the oxalate layering on top of that to form to form the stone. So those are the two most common. Um, and then there's uric acid stones which are very different because they're radiolucent, which means they don't show up on x-ray. So you can't so you can do an x-ray and it won't you won't see them. So that's not a good way of of checking for those. And they can also be dissolved and we'll obviously I think come on to that later. Um, so it's important to differentiate between those. Um, and I think traditionally a number of percentage wise was probably 5 to 10% of kidney stones are made of uric acid. But then when you consider obese and diabetic populations, it can be as high as 20 to 30%.
Dr Rupy: Ah, okay. Okay. Yeah. So one in three, if you're obese or you have diabetes will actually have uric acid stones.
Dr Matthew Bultitude: Potentially, yeah.
Dr Rupy: Ah, interesting. Okay. And what are the other types of stones that we're getting to the more rare sort of.
Dr Nish Bedy: Yeah, we're now getting down the list, aren't we? So I mean, cystine, which is the thing we mentioned earlier, is quoted in textbooks as being 1%. I don't think that's true in terms of what we actually see 1% of people coming in with cystine stones, but that's what textbooks say. So that's rarer. And then you there's a range of other rare types of stones. And you can get drug stones as well, and they are very, very different, but probably just worth a mention to say that certain drugs and certain HIV drugs in particular, which have been notorious for it, because because drugs are often excreted in the kidney. So there's high levels of of of that drug in the urine. And if certain for whatever reasons, that crystallizes out as well, then that can form a drug stone of whatever that that drug type was. Those are pretty rare, but also can be quite hard to find because again, they they don't often don't show up on they don't show up on x-ray or CT scan, which is the thing that most people will get if they want to come into the emergency department, you get a CT scan. Because it's not actually made of anything crystalline that shows up. So they can be more difficult to diagnose.
Dr Rupy: That that's really interesting from an A&E perspective actually, because if you're doing a CT scan, CT KUB, it's not going to come up on the but you've still got a high degree of suspicion and you you've ruled out other things. What then then what?
Dr Nish Bedy: Well, like on the uric acid stones you were saying that they're not you would usually see them on CT but not x-ray. So now with CT we tend to be able to see uric acid stones, which is good. But the drug stones that you mentioned, sometimes you just can't even see those on CT. So that is difficult. And then I guess it depends on exactly how the patient is, if they've still got pain or anything else with that, any other symptoms with that. But um, you may end up still going up inside and and doing a ureteroscopy, which is where you're basically putting a telescope up towards the kidney to see what the cause of that problem is. And actually this might I recently had my first drug stone I've seen really recently, which was where we weren't expecting to find that, but there was a stone that was causing the issue for that patient basically. Um, and we weren't expecting to find that, but when we looked inside, there was a stone and we ended up lasering it.
Dr Matthew Bultitude: Yeah. And so I think it is about having an index of suspicion and the doctors in the emergency department may not have that. But you may see secondary signs as well. So there's one thing on the CT scan of of actually seeing the stone itself. But then because it causes blockage, you you may well then just see a block kidney. You won't know why, but there's a block kidney with maybe some fluid that's leaked around it. So you'll see the secondary signs of that, which will then make you think, well, why is that happened? And if and you can also give some an injection of dye with the CT scan in those situations, which we don't normally do, but in that situation you might do. And then you see that excreted through the kidney and you'd see a sort of missing bit where the where that drug stone is. So then so that can help as well with diagnosis.
Dr Rupy: Yeah, yeah. And and moving down that list. So the rare stones. We got rare stones here. What were the the stones associated with chronic infections, which is an increasing issue, I think as we're seeing more antimicrobial resistance.
Dr Nish Bedy: Do you mean like struvite stones?
Dr Rupy: Struvite stones.
Dr Nish Bedy: Yeah. So that's we missed those out, didn't we in that in that percentage order coming down. So we're going back up. Yeah. So they're like magnesium ammonium phosphate stones related to sort of bacteria that's particularly proteus bacteria. But um, they kind of essentially split urea. And as a result of that, you end up getting urea which is in your urine normally. And as a result of that, you can end up getting stones essentially from excess crystals if you like.
Dr Rupy: Okay.
Dr Matthew Bultitude: And I think that's an interesting stone to treat because it's caused by the bacteria. So the bacteria live in the stone. And so people often getting recurrent infections, maybe seeing their GP, get given some antibiotics, get better, get infection again, get better. And that cycle goes on until someone does some a scan and usually finds they have this sort of very big classical stone called a staghorn stone when it fills all the calyces of the kidney. Um, and you really have to try and get rid of all bits of stone in that situation, otherwise, because because the bugs are living there, you can remove 70% of it, the 30% has still got bugs in it and it just it can grow very, very quickly again. Um, so so they can be challenging to treat as well.
Dr Rupy: Yeah. Is this a particular issue in women of menopausal age as well? Is that's an association that you you've seen?
Dr Matthew Bultitude: So well, infections are more common in women, aren't they? So you so they may be getting recurrent infections, which then lead to more alkaline urine, which leads to precipitation of this stone. The bacteria is there. So yes, yes, that's true.
Dr Rupy: Yeah, yeah. We're going to talk about urine alkalinisation and acidification in a bit because I think there's definitely something that I think there's a lot of misinformation around and there isn't too much.
Dr Nish Bedy: Well, that doesn't necessarily work for the struvite stones actually. I'm like you say we may come on to that later. But because the because of that mechanism to do with the bacteria instead. I think if I'm going to get it right or wrong, but it's essentially like urea is breaking down to ammonia and then you're getting a sort of hydroxide which is going to be making it alkali. So alkalinisation doesn't help in that case.
Dr Rupy: Exactly. Yeah, yeah. So so that's one of the unusual cases where you wouldn't want to have alkaline urine. You'd want to acidify it instead. We'll talk about it in a sec. I'm going to get myself confused. All right. So when we when we're talking about before we go into specific management of those particular stones, general advice that is been given by Bouse, I think you guys said it was the British Association of Urology.
Dr Nish Bedy: Surgeons.
Dr Rupy: Surgeons. There's all these acronyms. I forgot to pick you up on another one. What was the the journal that you were mentioning earlier, the British.
Dr Nish Bedy: Oh, the British Journal of Urology International.
Dr Rupy: Oh, there you go. Okay. Yeah, yeah, that's the one. All right. RSM is Royal Society of Medicine. Yeah, yeah, yeah. That's on me. I need to make sure that we're not using too much jargon because it's a complicated subject. So in terms of general advice, what what is one of the main things that you tell all patients when it comes to reducing the recurrence of stone and the risk of stone if there are a risk?
Dr Nish Bedy: You want to start with saying basically water.
Dr Matthew Bultitude: I thought you're going to do it at the same time. Water.
Dr Nish Bedy: Water, yeah.
Dr Matthew Bultitude: Um, yeah, I mean, the most common problem is people don't drink enough water. And so dehydration is common. So if you I I tend to say to patients, if you're going to change one thing, change the amount of fluid you drink. That is absolutely key to all stone types. There's no exceptions. Fluid is key. And for those who got infections as well, it's good, it's important for reducing infections as well. So if you're going to change one thing, change fluid. And typically we sort of say you should be drinking two to three liters a day. But that is going to be depend a lot on the individual, um, and where they live, their lifestyle. If you go to the gym and you lose a liter in sweat, you've got to replace that on top of that. And so really what the studies have shown is that you need to be producing about two liters of urine a day. So that's what comes out. And to do that, the typical person has to have about two and a half, three liters in to achieve that. But as I say, some people, if you run a marathon, you lose lots more than that. You got to replace loads more, haven't you? So so quite a useful guide is actually to either measure your your urinary volume if you want to in one a given day just to see what you're doing. But I also tell patients to just look at the color of the urine as well. You know, if you've had a few drinks, if you like beer and had a few beers, you go to the toilet, your your urine looks almost colorless, doesn't it? Or does look completely clear. Now, that's going to be hard to do in day-to-day life during the day. But actually the lighter it is, the more diluted it is, and that's because you're drinking lots and got lots of lots of fluid passing through and just flowing through the kidneys. So so that's good. Conversely, if you go to the toilet and it looks like treacle, so it's, you know, really yellowy, then that's a sign of very concentrated urine. And that's how stones form because they crystallize out in concentrated solutions. So that's a sign you need to be drinking more. And you're allowed to look like that first thing in the morning. You haven't drunk overnight. So you get up and you go and it's quite concentrated. But after that throughout the day, you want to try and get your urine looking much more dilute.
Dr Rupy: Yeah, yeah.
Dr Nish Bedy: Yeah. I mean, it's interesting because the um the the Bouse leaflet we we spoke about actually talks about tactics to try and drink that much water because it's not a normal thing that you would do. So I actually try and repeat that to patients and kind of in the spiel of telling like actually what you might try and do is have a glass of water or a pint of water first thing in the morning, then every time that you have some food, you have a glass of water before and afterwards, every time you go and pee, you have a glass of water when you come back. Um, and it kind of builds it into your day then that you're drinking throughout. Um, but then it's speaking to colleagues and like friends as well, um, they they said similar things like aim for colorless urine. But if that seems a bit vague to some people, and um, and then one of my colleagues actually at Imperial said that um, he said he bases it on the sort of motivation of the patient a little bit where if they seem very motivated to really know exactly how much, then he would give them a jug and say, um, you can measure your output and you're aiming for that two to three liters that you said, like you said, measuring. Yeah. As well. So then if they are motivated enough, they can keep track of it themselves rather than looking at input of like drinking two to three liters.
Dr Matthew Bultitude: And you only need to do that once. You only need to know once roughly what your urine output is. You don't need to do it for a lifetime every week you've got to test it because then you know roughly what, you know, if I go to the toilet six or seven times a day. Everyone's got a different bladder, so everyone's got a different bladder capacity. So some people have small bladders and need to go go every maybe store 200, maybe 250 mil. Some people who maybe been rugby players can store 600, 700 mil. And they only go four times a day, but they're probably making the same amount of urine. So actually the number of times you go during the day is not necessarily a reliable sign if you've got a smaller bladder capacity.
Dr Rupy: I've got a dog, uh, and uh, we've trained her to sort of like hold her her urine. Is that something that humans can do as well? Yeah, I'm just because we we have to keep on taking her out like out of our flat. We don't we don't have a garden. So, you know, we've been basically training her to keep her urine for a bit longer whilst still making sure that she's drinking enough water, particularly in the hot weather. Is that something that you you can do?
Dr Nish Bedy: Yeah, definitely. I mean, that we we call that things like bladder training or bladder drills for people with the the small capacity bladders we spoke about.
Dr Matthew Bultitude: So in that situation, that's correct because you want to try and train your your brain that you don't need to go so often. So actually you're going to let your bladder expand a bit more. But for other types of other groups of patients, doing that long term can be damaging to the bladder because you're over expanding your bladder. So we see that sometimes in certain professions, taxi drivers, bus drivers, people who can't go to the toilet regularly over years and years and years end up getting chronic retention where they get, you know, liter capacity bladders, which then slowly sort of stop stop working properly. So.
Dr Rupy: I wonder if it's the same in medics because I remember I got into a habit of drinking like 5 to 600 mils of water at the start of the day before the ward round because I knew during the ward round, like three, four hours or whatever, I wouldn't be able to drink any water just running around and stuff. So I wonder if that's the same.
Dr Nish Bedy: Yeah, I think sometimes in the hospital environment, it's the combination of not drinking anything and then not going to the toilet as well.
Dr Rupy: Yeah, yeah, exactly. Yeah, yeah. I don't know what that does to your bladder, but.
Dr Matthew Bultitude: I think surgeons who do long operations struggle with that as well. You know, you drink a bit and then you do if you start a 10-hour operation, you don't drink anything at all. That's really bad for stones.
Dr Rupy: Yeah, yeah, I can imagine. Um, I had another question there actually about, uh, oh yes, um, the timing of when you drink as well. So I I I was looking through a number of different patient leaflets from different hospitals, different trusts. And some of them suggest that you should drink before going to bed as well to to maintain sort of hydration levels throughout the night as well. And obviously, you know, that's going to mean that you're going to disrupt your sleep, you're going to have to get up in the middle of the night. Is that something that we have to also take into consideration, the fact that you should be hydrating throughout the 24-hour period?
Dr Nish Bedy: Yeah, I think it's that circadian drinking. Is that yeah, essentially, you know, if you're going to be dehydrated at any point, then that's going to increase your risk of stones. Like you were saying that first morning pee is going to be quite concentrated.
Dr Matthew Bultitude: So, yeah, I was going to say, so in that rare situation, we we do sometimes, well, we do. Um, but it life's got to be livable, hasn't it? So, you know, you don't want to be doing that so then you get up once or twice a night to go to the toilet just from a lifestyle point of view and then tiredness. So I think for a lot of the listeners who've had one or two stones, that isn't something you particularly need to be doing. There's any different from what you currently do. For very rare stone formers or very very common stone formers. So cystinuria is a classic example, then yes, they are often, you know, in extreme examples, we have probably only one or two patients, they actually set an alarm for the middle of the night to drink a pint of water. To right. So, but that is a real extreme. And if you think about it, what you want to do is just be trying to spread your water out throughout the day. You know, my example of the surgeon not drinking during the day, that's that's bad, isn't it? You're dehydrated all day. You can't then just have two liters at six and think that that solves that. You want it to be trying to continuous throughout the day. So I think like you said about having a glass of water, just drinking it regularly. I I have a a little 600 mil bottle that I carry. I can't believe I haven't got it now. I nearly brought it with me and I didn't. I should have done. But I actually keep it on my on my desk and I show patients and when they go, oh, I can't drink that much. I go, well, I can. Here's my bottle. Where's your bottle? Oh, I don't have one. Why not? And so many people are desk-based in their job. And actually, there should be no excuse for them why they can't do that to drink more. And I think if you if you get in the habit of doing it regularly, you then actually do feel thirsty and you do want to keep doing it. But you just got to get into that habit of just going every morning I come into work, fill up my bottle, drink it by 11, fill it up again, fill it up again after lunch, something like that. And then suddenly if you have three or four of those a day, that's two liters you've had of water on top of everything else you're doing. That's just a very simple way of just trying to trying to achieve that.
Dr Rupy: Yeah, definitely.
Dr Matthew Bultitude: And stones are a lot more common in the summer. There's a reason for that, isn't it? It's hotter, you're more dehydrated. So actually you need to drink more in the summer to replace the loss you get through sweat.
Dr Rupy: Let's talk about the type of water. Because I know that we're definitely going to be asked about that. You know, are there particular types of water we should be drinking? Is there a difference in the type of water you get in different parts of the country or different parts of the world? Should we be worried about that? I know you you've looked into that. You've probably been asked that a bunch of times, haven't you?
Dr Matthew Bultitude: Yeah, and patients always ask this question. Um, you know, where I live, the water's really hard. You should see what it does to my kettle. That sort of thing. So no wonder I keep forming stones. And you know, this idea that you're furring up inside by drinking water, which isn't actually true from hard water. So hard water is hard because of calcium carbonate, which isn't what stones are. I just said stones are mostly calcium oxalate. So but it does contain calcium. Um, but the the real, I would say the take home message is I think volume is the most important thing. So I don't think people should um, should need feel they need to spend money on expensive bottled water, particularly when I'm saying drink more of it, you've got to drink two or three liters. Well, that's quite expensive every day, isn't it? So it's actually volume that is important. And I think we're going to probably come and talk about calcium next, but actually calcium is important in the diet. And you don't and low calcium also increases your risk of stones. So actually the calcium you're getting in hard water may be important for a lot of the listeners with just general occasional stones. It may actually be important that they are getting that calcium. There will be some people who have high calcium in the urine where maybe you do not want to be, you want to have lower calcium diets. And maybe there, that is where soft water is more important. But I think those are the people who are should be being picked up in a hospital and being advised through through like a metabolic stone clinic or urologist or a nephrologist. So that I so I think for for general people who don't know that they're in that situation, um, I think it doesn't really matter what type of water is, it's just the volume.
Dr Rupy: Yeah.
Dr Nish Bedy: I think um, it it's kind of reassuring. There have been studies on this as well. So people have looked at the different types of uh water or fluid and uh it doesn't make a difference on your stone output. But um, we were just saying this earlier actually that it does look like some of the the fluid that you drink, like the mineral water, for example, or certain types of tap water can make a difference to your actual amount of calcium, for example, in your urine. But then it could be potentially buffered more. Um, so maybe that's why you don't form stones. We were saying this earlier, weren't we? But um, yeah, so essentially those studies have looked at that and it doesn't look like it's increasing your stones. So just like Matt was saying, it's about quantity really, isn't it?
Dr Matthew Bultitude: Yeah. And people have done big big studies, big population studies looking at hard water versus soft water areas to see if they have more stones. And the answer is they don't. So you can look at their urine and you will see that their calcium will go up a little bit. But as I just said, maybe that's a good thing. But maybe it's also buffered by an increase in citrate in the urine. So that's and citrate is an inhibitor of stones. So so overall, when you look at the hard end point of do you make more stones if you live in a hard water area compared to a soft water area, the studies have said you don't.
Dr Rupy: Yeah. Uh, let's talk about alkaline water now. Because I know that's the other thing. We're definitely going to be asked about alkaline water, whether it alkalizes the urine. Actually, I was doing a little bit of research and I typed in alkaline water on YouTube. And there's a YouTuber who's literally tested all the different types of water that's uh uh marketed as alkaline to see whether it is actually even alkaline. And a lot of them are just just normal, like neutral compared to tap water. It's interesting. Yeah, yeah. But you you had some thoughts on uh on alkaline water.
Dr Nish Bedy: Well, um, just because I when we were sort of planning, we mentioned this before, um, I thought I'd look it up and the uh the one that I looked up anyway, the couple that I looked up didn't have the same ingredients that we we would use to alkalinize the urine, which is something that we do sometimes suggest. So, um, I think on that point, uh, then I I suspect it wouldn't be as as useful for for stone reduction. Um, so that's the the thought I had now. So I don't think they would have the same quantities, but I didn't know that then if it's not even alkaline.
Dr Rupy: I it could have been like a sample issue. I mean, who knows, but yeah, but alkaline water, not worth your money.
Dr Nish Bedy: I I don't think so. I think but, you know, we can't say that for sure, I suppose, without testing.
Dr Matthew Bultitude: Uh, yeah. So I think we we sometimes in our in our clinic, we do if people do want to look at bottled waters, you can look at the amount of bicarbonate. So this is a slightly different thing, but you can look at the amount of bicarbonate on the label. So you can compare them and then ideally, you probably want a if you're choosing bottled water, something with a higher bicarbonate level, but with a relatively low sodium level. And they will go and they they could both go up together, in which case that's not necessarily good for you either. So higher higher bicarbonate, lower sodium if you're choosing one. That's different slightly different from alkaline waters which are being marketed. I don't think it's such a problem in this country at the moment. I know there's a huge issue in America. And there's um, a friend who's a professor of nephrology in New York, we've had over to London a couple of times. I think you've probably seen him speak. Um, I was spoken to him about it and he has a real bug bear about it because actually that alkaline water doesn't matter what that is. It doesn't it's all to do with the free bicarbonate in water. So it's got nothing to do with how someone is marketing it as alkaline water. So that isn't probably influencing the acidity of your urine at all. And therefore it's no beneficial for stones and you're spending a lot of money doing it.
Dr Rupy: Yeah, yeah, yeah. I I wanted to get on this a bit later actually, but um, just walk me through if someone has a stone or maybe has had two stones, what what would the management of that person be in terms of looking at their urine? Would we be sending off their urine for analysis to look at uh how their urine is faring over a 24-hour period? Is that something that's the norm?
Dr Nish Bedy: So generally once they're clear of stones is when you might do a more of an in-depth screen. Um, uh, beyond like basic blood tests. And you generally should be sort of risk stratifying people, which we there's no sort of formal way of doing that, I think, but it's a sort of rough guide of like the particularly high risk people, for example, if they've got one kidney or they're forming really frequent stones. Um, and then you might go into an in-depth um uh analysis of of why that might be happening with blood tests and with um a urine collection. Okay. Um, yeah, I don't know if you want to add into that now.
Dr Matthew Bultitude: Yeah, so if you try to identify high risk stone formers, you're normally talking about the very young. So anyone under 18 should definitely be investigated for a metabolic cause because that is not normal. Um, um, the EAU guidelines sort of suggest anyone under 30, anyone with bilateral stones, so you're getting stones in both kidneys, then that's a higher risk. Formation of big stones, so a staghorn stone would would would drive that. Um, possibly a very strong family history as well. So there are reasons why you might look more in depth. I mean, as a general screen, most people will will have looked at the other kidneys to know that the well, both kidneys to know that there aren't any other stones. We should be doing a blood test on everybody to know what the kidney function is, but also know what the calcium and the uric acid or urate levels are in the urine. That should be a minimum that everybody should should have had if they've had a stone episode before. Beyond that, it's more complex. And the way that we tend to screen people is with these big fluid collections, urine collections, 24, 48 hours, you get given these big things to carry around. You got to and they can be very frustrating to do. You got to bring them back. They got to be sent off. Often they get it's mislabeled, they get lost, they get spilled. Um, and I would say a lot in my experience, a lot of the time it is all normal. So you do all that effort and it's normal. So you've got to try and I think you've got to try and find the right patient. The one who's making coming back to you every couple of years, another stone. You want to be looking, is there anything else we can find in them that is beyond diet? So you're finding another cause. So, you know, hyperparathyroid or hyperparathyroidism is a cause. That's why we do the blood test for calcium. Um, other things. So those are the people you want to identify so you can offer offer different tailored advice, maybe some drugs to try and reduce their risk.
Dr Rupy: Yeah, yeah. Absolutely. We we've alluded to this already. Uh, so we might as well talk about it now. Calcium. Uh, so I I I was telling you before, I did a little poll of my not a formal poll, but like a little poll of some of my colleagues in primary care and actually in secondary care as well, some A&E colleagues. And uh, I asked them about whether we should be restricting calcium in the diet if someone is having frequent stones. And the majority of people said, yes, but that's not necessarily the case. In fact, that's the opposite of what we should be doing in the majority of people, right? In terms of dietary restriction to reduce the recurrence of of stones.
Dr Nish Bedy: Yeah, it seems counterintuitive because some of the other things that in stones we we might we'll be talking about, you may be able to reduce through your diet. But calcium, you've you've got a huge amount of calcium in your body. The first thing to say really, because your bones and your teeth are all calcium. So, um, the amount that you eat is not necessarily representative of your store of calcium. But therefore, if you start to lower the amount that you're eating, you might end up reabsorption more of the the calcium that's from your bones and your teeth, causing issues that way. Um, and it can actually put uh because of your hormone pathways as well, can put the calcium in your urine up. Um, so it can have a sort of counterintuitive effect where you then end up having more stones because of that. So calcium is um something to just have in your normal diet and to have a sort of normal amounts if you have even if you have calcium stones. But you're right, it's something that people might want to go to and reducing the diet and that would be the wrong thing to do in this case.
Dr Rupy: Yeah, yeah.
Dr Matthew Bultitude: Yeah. And studies have looked at that, haven't they? Studies have looked at trying to compare two groups, two randomized groups between a low calcium diet and a high and a normal calcium diet. And the people in low calcium diet had an increased risk of stone formation. So so people should definitely not, I tell people not to cut back on dairy particularly, unless you have a lot. Then of course it's working out what that means. And you know, I'm a urologist, I'm not I don't feel I'm in a position to really scrutinize someone's diet and say how much you're getting, how much milk, how much cheese, other sources of calcium. You know, if you're really want that depth, you probably need to see a dietitian or a nutritionist, I would have thought. But as a general rule, don't cut back on dairy and you want to have a normal amount, which is something like 1000 milligrams a day for for most adults. I think it goes up a little bit as as you get older.
Dr Rupy: Yeah, there's a there's a cut off like after when the risk of osteoporosis increases, that's when you want to increase it to 1.2 grams per day or 1,200 milligrams. But in the most adults, it's around 1,000 milligrams.
Dr Matthew Bultitude: And there's a relationship with oxalate as well, right? So if you're restricting calcium, that changes the oxalate absorption, which can increase the risk of calcium oxalate stones. Yeah, so most most we said most common type of stones are calcium oxalate. That's probably what most people have got. Um, oxalate is often the bad party in that rather than the calcium. We get all our oxalate, but some of it comes from the from the can be in the diet. If you and what it does, calcium and oxalate actually bind in the gut and then comes out in our in our feces. If you don't have the calcium, the oxalate is left unbound and gets absorbed in the gut. And then you so you're doing increase your amount of oxalate in your blood, which can then come out in the urine and will bind the calcium again and form your calcium oxalate stones. So that's why counterintuitively, you want to have a normal calcium intake to bind the calcium in the gut before the oxalate, sorry, in the gut before before it can be absorbed.
Dr Rupy: Yeah. We'll talk about oxalates in general actually in terms of whether a low oxalate diet is useful or whether it's recommended. But we're going to stick to the general advice for now because I want to keep keep people on on this journey. Um, salt or sodium more specifically. Uh, what what are our thoughts on on sodium restriction as as general advice for.
Dr Nish Bedy: So general advice is uh that you reduce the amount of sodium in your diet, um, and you reduce the amount of essentially calcium in your urine. So, uh, it's good for basically, I guess it's generally good for your cardiovascular health anyway. It's better to have less salt, sodium chloride in your diet for other health reasons as well. But for uh calcium forming stones, then it's going to uh, you know, potentially help. So I think that's good advice and we'd say that to everyone.
Dr Matthew Bultitude: Yeah, for sure. And the mechanism is that in the kidney, sodium and calcium go out together. So if you've got more salt, more sodium, sorry, that then goes out as a with the same transporter as calcium. So it puts more calcium out in the urine to then increase your risk of getting a calcium stone. So that's the mechanism for that. So it makes sense. So everyone would be advised to have a low salt diet. I think in our diet sheet at guys, we say six grams a day. I think some say less than three grams a day. But the principle is salt is bad for the body, bad for blood pressure, bad as you say for other cardiovascular risk factors. So, you know, I think everybody should be trying to follow a low salt diet. And there can be a lot of sneaky salt in diets, can't there?
Dr Rupy: Yeah, yeah. And in fact, the issue I find with salt in general and the conversation around salt is that most of the salt is coming from processed foods, which has got a lot of sugar in, a lot of other additives, a lot of things that can be harmful for the gut, which are all sort of like conspiring uh to disrupt your cardiovascular system and and sort of cause all sorts of like inflammatory issues. Um, and I was going to ask about that actually because in terms of some of the diet sheets that I've seen, they've recommended 5 to 6 grams, which is basically what the British Heart Foundation recommends as well. Some of them were quite low, so two to three grams, which is really. Is there any are there specific examples where a very low, a highly restricted sodium diet is is useful for particular stones or is that just are they are they just trying to be a bit more aggressive with the management?
Dr Matthew Bultitude: I think probably the evidence would suggest as low as possible. So if you so you say go aggressive. But like we said at the beginning, it's got to be livable. This is a lifetime risk we're talking about. This isn't just do it for a year and then then you can stop it. It's got to be it's got to be doable, hasn't it? So but it's useful for people to go away and just try and work out how much salt they are getting. How much processed foods, how much fast food, all the the salt you you know, people can say, oh yeah, I've stopped putting it on my food, but actually where you're getting it in other sources.
Dr Rupy: Yeah. Yeah. We we've also touched on this, but um, one of the recommendations was exercise, but as it pertains to weight loss rather than the exercise itself. So having a normal quote unquote weight or making sure that you're not obese or have metabolic issues.
Dr Nish Bedy: So I think obesity is linked with stones. So but it probably is a bit multifactorial as some of the other dietary things we might come on to in a minute. Um, but uh, so that I my understanding is that generally, yeah, exercise will uh uh reduce your weight, which is then going to have a knock on effect in terms of reducing stones. Obviously, the rest of your health benefits that we know about. Um, I suppose with stone formers, as we said, the important thing is then to be maintaining that uh fluid output or urine output still when you're exercising, you're going to probably dehydrate yourself a bit more. So get the balance right. Um, but yeah, that that's my thoughts on weight loss.
Dr Matthew Bultitude: And exercise contributes to an overall healthy lifestyle, doesn't it? Yeah. You know, if you're someone who exercises regularly, you're probably you're probably not having burger and chips once a day. You know, it's part of your health, it's what you're doing, it's part of a healthy lifestyle, isn't it? And you're regulating your weight and then weight is, as you say, obesity is linked with with increased risk of kidney stones.
Dr Rupy: Yeah. There's quite a few crossfitters who love a low carb keto diet. So and that brings you nicely on to the next uh the the next part of the general advice, which is protein in general. And but we're specifically talking about protein from animal products. Uh, is that right?
Dr Nish Bedy: Yeah. So it's a bit of a contentious subject, I think, because, you know, some people are like, well, I need quality protein in my diet, you know, it's useful for uh the exercise I'm I'm doing, uh osteoporosis, you know, uh after menopause, particularly people are quite um uh cognizant of the amount of protein in their diet for their health benefits. Um, however, a high protein diet with too much of the purines and methionine can contribute to stones. Is that?
Dr Nish Bedy: Yeah, I think um, animal protein particularly has a it's important obviously to have protein in your diet, but if you have um animal protein, which includes uh supplements that may be derived from animal, for example, uh products like dairy, so whey protein and so on, then uh the issues there are um to do with acidifying your urine uh as a result of the uh amino acids in that. So, um, that's quite specific to high levels of animal protein in your diet and that that can increase your risk of those types of of of stones from the acidification point of view. Um, I guess we can't really say therefore that you should have lots of vegan protein instead, but, you know, you could eliminate that to improve your sort of risk factor from that side.
Dr Rupy: Yeah.
Dr Matthew Bultitude: Yeah. Protein is important. Getting enough protein is important, isn't it? That's a message we give in our cystinuria clinic. For the children, we don't they don't limit their protein intake at all because it's important for growth. Uh but in adults, I mean, you know, we talked about why people are getting stones, Western diets. How common was 100 years ago, how common was meat on a on a table? Probably very rare, probably a real treat. Now, most people probably do it every day and just view that as routine, isn't it? So there is a problem, I would say with animal protein, we're having too much. Um, and so and it's been linked, as you say, it acidifies the urine, linked with calcium oxalate stone formation, uric acid stone formation, which are the two of the big common types of stones we've talked about. So, you know, the general advice is to try and cut back on animal protein. I tend I try to tell patients to have one or two vegetarian days a week. So you don't it doesn't say you can't enjoy life, you can't enjoy a steak, but just be aware of that that is increasing one of those things that does increase your risk. And actually, maybe it's fun to try and cook at home and do a vegetarian one every Wednesday is a vegetarian day. Something like that just that makes it fun as well.
Dr Rupy: Yeah, yeah. Are vegetarians less I haven't looked at this. I'll probably have to go and do some research, but are vegetarians less likely to have stones for that reason or is it is it not shown in the data?
Dr Nish Bedy: I don't think specifically vegetarians, but the vegetarian diet in general will have more alkaline urine. So that's we know that's beneficial as we've said, you know, alkalinization of the urine is protective. So from that point of view, yes. I think that's uh that would be protective.
Dr Matthew Bultitude: Yeah. So fruit and vegetables are good. So fruit and vegetables do the opposite of animal protein. Fruit and vegetables cause alkalinization of your urine. So, um, so it stands to reason there that a following a a typical vegetarian diet rather than high animal protein diet will is the sort of diet we're trying to say to stone formers you should be having. So so yes, I think is the answer to that.
Dr Rupy: Yeah, yeah. And I I guess it also increases your fiber consumption as well, which reduces the absorption of of calcium in the gut.
Dr Matthew Bultitude: Yeah. So fiber is good. Yeah.
Dr Rupy: Yeah. Yeah. Let's talk about the type of water. Because I know that we're definitely going to be asked about that. You know, are there particular types of water we should be drinking? Is there a difference in the type of water you get in different parts of the country or different parts of the world? Should we be worried about that? I know you you've looked into that. You've probably been asked that a bunch of times, haven't you?
Dr Matthew Bultitude: Yeah, and patients always ask this question. Um, you know, where I live, the water's really hard. You should see what it does to my kettle. That sort of thing. So no wonder I keep forming stones. And you know, this idea that you're furring up inside by drinking water, which isn't actually true from hard water. So hard water is hard because of calcium carbonate, which isn't what stones are. I just said stones are mostly calcium oxalate. So but it does contain calcium. Um, but the the real, I would say the take home message is I think volume is the most important thing. So I don't think people should um, should need feel they need to spend money on expensive bottled water, particularly when I'm saying drink more of it, you've got to drink two or three liters. Well, that's quite expensive every day, isn't it? So it's actually volume that is important. And I think we're going to probably come and talk about calcium next, but actually calcium is important in the diet. And you don't and low calcium also increases your risk of stones. So actually the calcium you're getting in hard water may be important for a lot of the listeners with just general occasional stones. It may actually be important that they are getting that calcium. There will be some people who have high calcium in the urine where maybe you do not want to be, you want to have lower calcium diets. And maybe there, that is where soft water is more important. But I think those are the people who are should be being picked up in a hospital and being advised through through like a metabolic stone clinic or urologist or a nephrologist. So that I so I think for for general people who don't know that they're in that situation, um, I think it doesn't really matter what type of water is, it's just the volume.
Dr Rupy: Yeah.
Dr Nish Bedy: I think um, it it's kind of reassuring. There have been studies on this as well. So people have looked at the different types of uh water or fluid and uh it doesn't make a difference on your stone output. But um, we were just saying this earlier actually that it does look like some of the the fluid that you drink, like the mineral water, for example, or certain types of tap water can make a difference to your actual amount of calcium, for example, in your urine. But then it could be potentially buffered more. Um, so maybe that's why you don't form stones. We were saying this earlier, weren't we? But um, yeah, so essentially those studies have looked at that and it doesn't look like it's increasing your stones. So just like Matt was saying, it's about quantity really, isn't it?
Dr Matthew Bultitude: Yeah. And people have done big big studies, big population studies looking at hard water versus soft water areas to see if they have more stones. And the answer is they don't. So you can look at their urine and you will see that their calcium will go up a little bit. But as I just said, maybe that's a good thing. But maybe it's also buffered by an increase in citrate in the urine. So that's and citrate is an inhibitor of stones. So so overall, when you look at the hard end point of do you make more stones if you live in a hard water area compared to a soft water area, the studies have said you don't.
Dr Rupy: Yeah. Uh, let's talk about alkaline water now. Because I know that's the other thing. We're definitely going to be asked about alkaline water, whether it alkalizes the urine. Actually, I was doing a little bit of research and I typed in alkaline water on YouTube. And there's a YouTuber who's literally tested all the different types of water that's uh uh marketed as alkaline to see whether it is actually even alkaline. And a lot of them are just just normal, like neutral compared to tap water. It's interesting. Yeah, yeah. But you you had some thoughts on uh on alkaline water.
Dr Nish Bedy: Well, um, just because I when we were sort of planning, we mentioned this before, um, I thought I'd look it up and the uh the one that I looked up anyway, the couple that I looked up didn't have the same ingredients that we we would use to alkalinize the urine, which is something that we do sometimes suggest. So, um, I think on that point, uh, then I I suspect it wouldn't be as as useful for for stone reduction. Um, so that's the the thought I had now. So I don't think they would have the same quantities, but I didn't know that then if it's not even alkaline.
Dr Rupy: I it could have been like a sample issue. I mean, who knows, but yeah, but alkaline water, not worth your money.
Dr Nish Bedy: I I don't think so. I think but, you know, we can't say that for sure, I suppose, without testing.
Dr Matthew Bultitude: Uh, yeah. So I think we we sometimes in our in our clinic, we do if people do want to look at bottled waters, you can look at the amount of bicarbonate. So this is a slightly different thing, but you can look at the amount of bicarbonate on the label. So you can compare them and then ideally, you probably want a if you're choosing bottled water, something with a higher bicarbonate level, but with a relatively low sodium level. And they will go and they they could both go up together, in which case that's not necessarily good for you either. So higher higher bicarbonate, lower sodium if you're choosing one. That's different slightly different from alkaline waters which are being marketed. I don't think it's such a problem in this country at the moment. I know there's a huge issue in America. And there's um, a friend who's a professor of nephrology in New York, we've had over to London a couple of times. I think you've probably seen him speak. Um, I was spoken to him about it and he has a real bug bear about it because actually that alkaline water doesn't matter what that is. It doesn't it's all to do with the free bicarbonate in water. So it's got nothing to do with how someone is marketing it as alkaline water. So that isn't probably influencing the acidity of your urine at all. And therefore it's no beneficial for stones and you're spending a lot of money doing it.
Dr Rupy: Yeah, yeah, yeah. Let's talk about urine alkalinisation and acidification uh as it relates to to stones. What what do we mean by by this? Because there's a bunch of uh diets out there uh over the last, you know, couple of decades that have, you know, claimed to alkalinize your body. And I think there is a sort of implied it it's sort of implied that it changes your blood pH level, which, you know, as as we all know is is not going to happen. Um, so what do we mean by by urine alkalinisation and and acidification?
Dr Nish Bedy: Well, um, in general terms, what for what we mean, uh, when we do it, it's sort of for for stone patients is that you're uh giving medication to achieve that rather than just doing it through purely through your diet. Um, and typically it would be something like potassium citrate that that's how you can um, and you can have strategies for doing that. But then that's sort of taking it through the day that then ends up uh with them having alkaline urine compared to the normal pH for urine. Um, so that's what we mean sort of in general terms for us if that's like a broad view. And then obviously like we said, for most stones, that's going to reduce your risk. I mean, the exceptions we said like we've already mentioned those sort of struvite type of stones. Uh, and pure calcium phosphate stones as well. So you wouldn't do it for those types, but everything else would pretty much uh have a benefit from that.
Dr Matthew Bultitude: Yeah, and I suppose to explain that slightly differently, the pH of the body the urine is actually quite a tight range. It's between 5.5 and 8. So whereas you can buy pH strips that measure from north or one to 14, actually, you're not going to get you don't get urine, it can't it's not physiologically possible to have a urine of pH 3 or 13, 14. So it's quite a tight range. And so what we tend to see is in the more acidic urine, so that's on the sort of 5, 5.5, maybe six level, you increase your risk of getting calcium oxalate and uric acid stones. If you can get that level that pH level up to more like 6.5, 7, then you significantly reduce that. And in fact with uric acid, you can actually dissolve them. So you don't you really do prevent it by getting there because because actually it moves that the uric acid sort of dissociation point in the urine so that it's fully dissolved if you can reliably achieve about 6.5 to 7.
Dr Nish Bedy: You can have amazing results with like really big stones, uric acid stones just be dissolved.
Dr Matthew Bultitude: It's the only type of stone you can dissolve. So patients often ask that, can you dissolve this stone? So yes, in the situation that is uric acid. But that does happen and we have seen that with as you say with complete staghorn stones that can that can be dissolved. Interesting. Um, and then just finally to say sort of and we I was saying talking a lot about cystinuria and cystine stones, but that's another one where actually the more alkaline you can make it, the more it gets dissolved in the urine. So we actually aim for even higher than, which is more like 7.5 to 8. And if people can achieve that, then that does significantly reduce the amount of of solid cystine in the urine. So that obviously reduces your risk of stone formation. The risk with all of this is if you get it too high, you then can precipitate calcium phosphate, which you just mentioned is why you wouldn't do it. So in situations where you have a calcium phosphate stone, you do not want to be up in the you don't want to be over alkalizing the urine and getting it up to 8, 8.5, anything like that. But again, for the majority of people listening, that is not you. So, you know, for the majority of people, you would you probably if you're getting that and getting it regularly, you're going to be under a urologist, under a stone clinic and you're going to know that's your type of stone. So most people are going to have calcium oxalate stones.
Dr Rupy: Yeah. On on that note, uh, is there any rationale for somebody who has recurrent stones to check the pH of their urine on a weekly basis using a strip, using a strip? They're very easily, you know, purchasable, cost a few quid.
Dr Matthew Bultitude: I suppose it would be useful to I mean, I've not ever suggested it to anyone, but it would be useful to know, obviously. I think for someone who's had one or two stones and worried about about stones for the future, probably isn't particularly useful because I think you just want to follow it's more important to just focus on the things we've talked about. So focus on fluid, focus on just a healthy diet, low salt, mixing up the diet, not too much all of that, rather than going, oh look, my pH is 5.5 or my pH is 7. What does that mean for someone who's had a stone every five years? That probably doesn't mean anything at all. I mean, we do give um, I do advise people to test their urine. So if they've got uric acid stones, you want to and we're deliberately alkalizing their urine in the stone clinic, then we get everyone to try and measure their their urine pH either with dipsticks or with pH meters. And actually, we did a little study on that and you can buy really cheap pH meters on Amazon say for about 10, 15 pounds, which are just as reliable as pH meters that have that are 100 pounds and probably more accurate than strips and stuff or or certainly comparable, but much easier to do because otherwise the strips you're looking at. Is that that shade of green or that shade of green? You're not you're not sure. Whereas this just gives you a very accurate digital reading. So for those patients, um, yes, I definitely definitely is useful. And we get all our system patients to do it obviously, but again, that's that's a niche uh a niche group of patients.
Dr Rupy: And just to clarify, you'd be alkalizing the urine using medications in those instances or is it would would it be through diet as well?
Dr Matthew Bultitude: So so the principles of diet are there and people should be doing it anyway. But yeah, we we're alkalizing the urine deliberately because they because they've got a uric acid stone that either you don't want they keep getting it and you want to prevent it. So you get the urine pH up or or you're dissolving it or in cystine or something like that where you're and and so yes, we're deliberately giving medications there to alkalize their urine. And we want to check that the medications are actually having the desired effect because there's no point giving the medication and it's not making any difference to the pH. So you need to know in that situation.
Dr Rupy: Yeah, yeah.
Dr Nish Bedy: So with that, with those pH meters, did you find that they're I'm not seen that before. Was there pH varying a lot during like a weekly basis for those patients or?
Dr Matthew Bultitude: Um, it does fluctuate a lot during the day. Yeah. So, um, it's got a lot to do with what we eat and drink, not surprisingly. But it is fascinating. We've had a couple of patients who look really in depth at this in our system. They're a very driven group of patients to um, uh, to look at this and done some amazing diaries of every single time for a few weeks they've done it. If you have a steak, you can see that pH goes down. You know, if you have a beer, it goes down a bit, but um, and then they just drink more water and it comes up a bit and you can see. So that one in particular, that patient in particular I'm talking about really showed beautifully the effect that diet can have. And he was then compensating. And then he stopped doing it, but he says, I now know what I'm doing. So I'm still going to enjoy a steak, but I know I'm going to drink more water when I do it because I know it's going to cause my my urine pH to dip.
Dr Rupy: I think that's a really important point actually, because all these things are just tools that give us a bit more granularity on how we are reacting to what we eat and drink. So it's the same thing with like continuous glucose monitors. It's just a tool. A lot of people, I think, can go a bit too in depth with it and just eat fat, for example, which is just going to keep your glucose level completely flat. As long as it's fat with no sugar in. Um, but that's not going to be a a good strategy lifelong for having that. You want to have all the other elements in your diet. So this, I think, is it's good to do for a little while to see how you react, but not necessarily something that you want to get overly obsessed with.
Dr Nish Bedy: I think that's right. It's a kind of understanding tool, isn't it as well?
Dr Rupy: Yeah. Yeah.
Dr Matthew Bultitude: But I think that's why we kind of risk stratify a little bit when we're deciding treatment. So not everyone is going to have that full in-depth like extensive blood work and metabolic stone screen because it's just not necessary because stones are, like we just said, are so common. You get one in 10, one in eight people having them in their life. Um, and that might just be their one stone that they have. You know, then they maybe had a bit more fluid into their diet or whatever and it and you don't need to kind of, you know, go crazy chasing your urine pH every day or every like throughout the day. Whereas for that the sort of cystine patients you mentioned that where they are doing that, that could be really relevant because that will help them balance it out.
Dr Rupy: Yeah. Yeah. Green juice is really popular. Particularly raw green juices where you have literally like a bag of kale, a bag of spinach. Every now and then, all good. But some people will have this every single day. Are they putting themselves at risk of stones given what we just talked about with regards to the fact that it's high in oxalates, but it's also going to alkalinize your your urine as well.
Dr Nish Bedy: Yeah. So we're doing about oxalates.
Dr Rupy: Yeah, let's talk about oxalates.
Dr Matthew Bultitude: So, yeah, so oxalates common type, most common type of stone, calcium oxalate. So, but only about 10 to 15% of oxalate comes from the diet. So most of it's made by the body. So 85% of it you can't do anything about. So that's number one to say. Um, you can look online and find huge lists of um, foods that have got different oxalate levels and break it down into high, medium, low, etc. But a lot of the stuff that you find in those lists is actually really healthy stuff. So spinach you mentioned then is one of the ones that is actually on the particularly high end of the spectrum with oxalates. But it's healthy in other ways. And fruit and vegetables are good and they help to alkalinize the urine and. So I tend to people they I tend to tell people that they can have a look at that list. If you have any one of those in particularly high quantities every day or all the time, then you might want to just moderate that. But that doesn't mean you have to cut it all out because otherwise you're cutting out a lot of very healthy things as well. So but again, it's just about awareness, I think. You know, life's there to be enjoyed. If you enjoy eating that and it's healthy, then then do it. But just be aware of what that's doing. And maybe just drink more water with that. So if I'm going to have something that's high in oxalate, well, I'll just drink some more water to counterbalance that. It's a sort of general advice I try to give rather than people going, oh yeah, I've cut this out, cut this out, cut this out, cut steak out. You're like, well, what what are you enjoying then?
Dr Rupy: Yeah, what are you eating?
Dr Nish Bedy: Yeah. I think that's it because you can in general terms as well, everything else is a bit easy because you can say, look, water, drink lots. We've told you the strategies. So you've got to reduce that, protein you've got to reduce that. Then you come into oxalates. And people are like, you know, generally the public and the patients won't know what that is. And I don't think I would unless, you know, I did this job and looked into it. And like you say, the list is it's lots of fruits, vegetables, nuts, sesame seeds for some reason, you know, soy products as well. Um, so uh, it's a really broad spectrum of things. And I think that's most of the advice would be avoid excessive consumption. Because your body produces oxalates anyway and you know, it's involved in other um metabolism, like we've said. So there will still be oxalates there regardless of what you do with your diet. But if you are forming lots of calcium oxalate stones and you do have an excessive amount of one of those things, then it is something to look at and reduce.
Dr Rupy: Yeah. Where's most of the oxalate coming from? You mentioned it earlier.
Dr Nish Bedy: Well, it's it's kind of a byproduct of like respiration essentially in your body. So you're you're making it anyway. Um, but there is a certain amount that's coming through your diet as well.
Dr Rupy: Yeah. I I looked through these lists and this is basically what I use to make all my recipes. So it's got it's got nuts, sesame seeds, peanut butter, some fruit, tangerines, plums, rhubarb, soy products, like a lot of stuff. And and I guess uh we were talking about this before before in terms of if you have a moderate oxalate consumption and you're reducing your calcium levels, that's going to increase your risk of uh calcium oxalate stones as well. So it yeah, it's just something to to bear in mind, I guess.
Dr Matthew Bultitude: Yeah, bear it in mind, but don't go crazy with it and um, there's a there's a lady I'll give a shout out to her, Christina Penniston, who's a dietitian in Wisconsin who who I know quite well and also had over to London recently and gave us a gave a talk at the at the Royal Society of Medicine. Um, and she's just written an article saying don't cut back on oxalates. She's a dietitian because of because of actually all the benefits in most of those that food stuffs that you get. Look at the other bits. Look at the animal protein bit of it. You know, look at the balancing thing is to sort that bit out, not to not to cut back on what is what is largely healthy stuff.
Dr Rupy: So I think you're okay with all your. Yeah, that's great. Yeah. Um, vitamin C and oxalate. Uh, is that something people I mean, vitamin C has become very popular post-COVID as well.
Dr Nish Bedy: Well, I think it's interesting actually because I in general in your your medical history, I I've not really asked about vitamins or supplements before. Um, but uh, I guess more like reading around for this talk as well, looking into vitamin C. And um, essentially a lot of people like you say having high dose vitamin C, it's a precursor for oxalates. So they may be unwittingly sort of putting a lot of oxalates into their diet. Um, and if if you're having over like a gram and some people are having like three grams a day, then they're going to definitely uh raise the amount of oxalates in the body and probably in the urine. Um, probably okay for most people, but again, then if you are forming calcium oxalate stones, that might be the reason why or that might be contributing to it. So something to be aware of, I guess.
Dr Matthew Bultitude: Yeah, and I've got much to add to that, but definitely vitamin C intake being correlated with increased risk of kidney stone, calcium oxalate kidney stones. And it's not something we usually ask about or I've not until now. And you might not be told what drugs you take. You don't patients don't say, oh yeah, it's a supplement. They don't mention it. So yeah, and it is the high dose, isn't it? It's 500 or greater. You know, kind of dose.
Dr Rupy: How high? Like 500 milligrams?
Dr Matthew Bultitude: Oh, okay. Or greater. Because there's something like you need about 60 milligrams of vitamin C a day. That's why for to do normal.
Dr Nish Bedy: There are some some sort of recommended like up to a gram or even more like you know, I've seen before. So.
Dr Rupy: One to four grams is what people have been taking as a as an antiviral sort of dose. So yeah, pretty high, pretty up there.
Dr Matthew Bultitude: Um, yeah, but if if you've never made a stone, I think you probably keep going with what you're doing, don't you? If you're making a lot of stones, you're making calcium oxalate stones in particular, then you probably should look at that and work out what the risk benefit ratio is because there's definitely a risk to taking it. So where's your benefit? You know, where's the actual evidence that taking those high doses is beneficial?
Dr Rupy: Yeah, yeah, yeah. Um, we were talking earlier a bit about um, the uh overly acidic urine being the main risk factor for uric acid stones. Um, when people think of uric acid, they think of allopurinol, uh, which is a medication that we use for gout. Has that been shown to be effective at all or is that is that old-fashioned advice?
Dr Nish Bedy: No, allopurinol is very effective at lowering your uric acid in your your sort of blood particularly. And I think as a knock on, then it will help with your urine. Um, but I don't think it it specifically lowers the urine uric acid. Um, that's my understanding of it. Um, but yeah, definitely if your your uric acid is high in your in your bloodstream, then you you would be suggesting that.
Dr Matthew Bultitude: And that's why one of that's one of those mandatory blood tests I said earlier, you should do is uric acid or urate to know that. So, um, so yeah, if you're getting gout and you've got a high urate and you've got a uric acid stone, then I think it's no brainer you should be on you should probably you'll be advised to take allopurinol. Um, not sure a lot of people have very with uric acid stones necessarily have high urate levels. So if if the blood level is normal, then there is no benefit to taking allopurinol. Gotcha. So, but there is clear benefit to alkalinization of the urine. And as I say, if you can you can reach a certain level where it will be fully dissolved if you if you can achieve that that level of alkalinization.
Dr Rupy: I feel like I'm going to have like a green salad and check the pH of my urine. I've never done that before. But just out of interest, I think it would be. Because there are no there are no symptoms of like if you were to have a steak or, you know, beer and whatever, there aren't any specific symptoms of acidic urine, are there? Assuming that we're not doing it long term, we have a stone.
Dr Matthew Bultitude: No. You wouldn't know. You wouldn't know at all. You'd never know.
Dr Rupy: Yeah, yeah. Okay, great. Uh, any other specific dietary factors for specific types of stones before we move on to supplements?
Dr Nish Bedy: Uh, I think that's yeah, I mean.
Dr Matthew Bultitude: What have we done? Um, drinks, different types of drinks we haven't talked about.
Dr Rupy: Oh, yeah, let's talk about that. Yeah, good drinks, bad drinks.
Dr Matthew Bultitude: Yeah, yeah, tea, coffee, fizzy drinks.
Dr Rupy: Yeah, let's talk about that.
Dr Matthew Bultitude: Um, so it doesn't have to be water. So water's boring. Yeah. People ask about beer. I love water. So you can definitely flavor it. Number one. Um, you know, that's absolutely fine and like we keep saying, it's the volume that's important really. Yeah. Um, one way of flavoring it which is good is to put lemons in it. So, um, lemons is a very natural way of alkalizing your urine. And I quite commonly say to patients to squeeze and there is evidence for this, to squeeze the juice of one or two whole lemons per day into a liter of water. So get a big liter jug, squeeze one or two whole lemons in and then drink that as your as your throughout the day as your as your fluid. And you're getting the benefits of all that citrate from the from the lemons naturally, which will alkalize your urine and and it's a way of flavoring it as well. So that's a really good thing to do.
Dr Nish Bedy: To be really sort of geeky on this, I had to look into this and to see what like whether that was good advice or not because I think I've definitely heard it throughout and I've said it to people as well, whether it's a few drops or like two lemons. Um, but I think what what I tend to eventually see was essentially that the citrate may end up um becoming more of a like a bicarb buffer because I was thinking actually is citrate something that you drink like the lemon juice citrate there going to end up in your your urine or not because that's obviously citrate is a buffer in your urine that we we're hoping will help. But um, I think it looks like probably through metabolism, it's not going to end up there. But um.
Dr Matthew Bultitude: But it but it increases the bicarbonate. So you're right. Because citrate as a stone inhibitor naturally in the urine. But lemons and things like that don't or potassium citrate, potassium citrate either, they don't increase your citrate level specifically in the urine. But they but they increase the bicarbonate and by increasing the bicarbonate, that that causes your citrate to go higher in the urine. So that's the mechanism.
Dr Nish Bedy: So I had a moment where I was like, oh, I shouldn't be suggesting them juice and then I went back to, oh yeah, it's good. But for another reason.
Dr Matthew Bultitude: But the mechanism is through bicarbonate, which is why your citrate goes up in the urine. Not that it just goes through the body and suddenly comes out as the same lemon juice.
Dr Rupy: Is that the same for all citrus fruits then? Like, um, limes or grapefruit or or is it specifically lemons?
Dr Matthew Bultitude: I think lemons and limes are equally good. Okay. Equally ish. Um, grapefruit, I think is okay, probably not. I think lemons and limes are the best. Orange less so, but you do read different things and get different different take home messages from stuff.
Dr Nish Bedy: Some people say that some certain like fruit juices and things and like I guess you're going to come on to it as well, could be harmful because of like the other side effects with having like more acidity and so on. So it's yeah, you always sort of it's a delicate balance, isn't it?
Dr Rupy: The acidity from that maybe coming from the sugar? So if you're having a fruit juice, which is something that we don't recommend anymore as part of um, you know, if you're literally having like apple juice, you've got rid of all the fiber, you have a high amount of the natural sugar, fructose. Um, and so you're basically having the equivalent of like a sugar sweet beverage like Coca-Cola or whatever, which can increase your uric acid level as well. Um, so that might be one of the reasons why.
Dr Matthew Bultitude: I think that would be contributing probably.
Dr Rupy: Uh, other drinks, sorry. So we're going off on a tangent of lemon juice there, which I liked.
Dr Matthew Bultitude: Um, so um, in general, tea is considered to be bad. A little bit controversial in studies because some big studies that have grouped everything together have sort of not shown a difference. So there may be a volume effect that's that's playing out there as well. But tea does have oxalate in it. So again, just be aware of that. If you have 15 cups of tea a day and people do. A lot of people do. People do, then that is probably that is too much.
Dr Nish Bedy: I think I could say that's black tea, isn't it? Rather than green tea just in case people.
Dr Rupy: I was going to say, yeah, like is it English breakfast, Assam.
Dr Nish Bedy: The black tea that have the oxalates in it. So other things may be okay or.
Dr Matthew Bultitude: Yeah. And it's the difference between brewing time as well. If you're someone who dips the tea bag in and takes it out, then that is going to be far lower risk than someone who lets it stew in there until the teaspoon almost stands up in it. So there's a there's a massive difference in difference in that as well. Um, and then regarding fizzy drinks, in general, carbonated these carbonated drinks are bad for kidney stones. But certain ones are worse than others. So things like diet Coke, diet Pepsi, that sort of thing. And it's because they're acidified using phosphoric acid.
Dr Nish Bedy: Phosphoric acid, yeah.
Dr Matthew Bultitude: So if you're going to have anything, you're better off with things like diet, and they're all better being diet because of the sugar, like you mentioned. So diet seven up, diet Sprite, diet Sunkist. Those have been shown to be better because they've got they're acidified with citric acid.
Dr Rupy: Ah, okay. Interesting. So it depends on the it's on the ingredients list.
Dr Matthew Bultitude: Yeah. Yes. Yeah, you can see on the.
Dr Nish Bedy: That's what I was thinking when we were saying earlier about sugar. I was thinking the the acid component is yeah, is different and important.
Dr Rupy: Yeah. But some people drink a liter of Coke a day. Yeah, yeah. I mean, that's not uncommon. And that is definitely that's increasing your risk.
Dr Matthew Bultitude: Yeah.
Dr Rupy: Yeah.
Dr Nish Bedy: I don't think I had anything else with fluids, did you? I think that's my main list.
Dr Matthew Bultitude: Alcohol, I suppose. Yeah. Yeah. Some of your listeners might drink alcohol.
Dr Rupy: Oh, yeah. I mean, I enjoy a nice glass of wine every now and then.
Dr Matthew Bultitude: People always ask about beer because they're like that if I drink lots of beer, then I'm peeing loads. Yeah, yeah, yeah. I don't think you can really recommend it. No. Although I came across, I don't know how up to date this was. I think it was from like 2019. They found that uh moderate drinkers actually had a slightly reduced risk of stones, which I I personally didn't understand, but yeah, so it seems that as long as you're not drinking excessively, it shouldn't be an issue and you're hydrating properly, but.
Dr Matthew Bultitude: Yeah, I mean, I sort of fall back on the normal advice about alcohol and not being excessively anyway. So actually you shouldn't be doing that from a lifestyle point of view, should I? So, you know, your standard 14 or 21 units, whatever it is per week type of advice. But I guess you're that's all it is fluid, isn't it? But that's not the recommend it's not recommended you should have two pints of beer a day. But people often would colic. So when they get colic pain, say, oh, I'm going to drink more beer because then flush it out. And there probably is something in that, isn't there? Because actually you do want to make sure you're maintaining good hydration. You don't need to go crazy, but maintaining good hydration. So some people do swear by that.
Dr Rupy: Yeah. Um, citrate supplement. I'm on the subject of lemon juice. I just wrote citrate supplement. You can get citrate supplements these days. Is that something that we use at all? Is there any evidence?
Dr Nish Bedy: Would that be do you know what that's combined with?
Dr Rupy: Not too sure. Yeah. I just I just wrote it down as we were talking about lemon juice and the impact of citrate on oxalate stones specifically.
Dr Matthew Bultitude: Yeah. Is that something you looked at in your supplement? Well, I mean, so we alkalize the urine with potassium citrate. That's what we use. That's what we use. And it can come in different forms. So, um, and so, yeah, and that can be liquid, effervescent tablets or or tablets, but they're very hard to get a hold of. But that's the medical forms. Yeah. I think on Amazon, you can find all sorts of things. Yes. But it's very hard to advise on those because we don't really know what's in them. Uh, there are some well-known brands in America. There was a couple of papers that have got like a list of 10 of the top brands. And they do actually list the alkali quantity the quantity in them because that's the important thing. And what what I wouldn't I don't know by just looking at a thing on Amazon and going, oh, yeah, that is whether that's good or bad. What is actually in it? What you're marketing it for. So but potentially something that's like that will be good at alkalizing the urine. And generally that's a good thing to do.
Dr Rupy: Okay. Fine. Um, let's without recommending it. Without recommending it. Yeah, yeah, yeah. I think with all this stuff, you you really do need to like work with your primary care physician as well or your urologist if you if you have one. Um, vitamin D is very common. I recommend vitamin D as something that people should at least get checked. A lot of it's part of government guidance during winter months, particularly for people with darker skin complexion. Uh, adverse effects of vitamin D, um, are there any?
Dr Nish Bedy: Vitamin D is the sort of that you don't want it too high or too low. You want the sort of Goldilocks in the middle. In the middle, yeah, essentially. So if it is too low, then um, yeah, exactly. You can cause uh issues with that as well. Um, because it's linked with your calcium again. So it's essentially increasing your calcium uh reabsorption. So you want it in the right levels or it's not too excessive essentially.
Dr Rupy: Yeah.
Dr Matthew Bultitude: But how do you know that unless you're getting it tested? So therefore you should have it tested. So particularly people who have come to see us with kidney stones and they're on vitamin D, you know, do you actually need it? Why are you taking it? If it was given by their GP because of medical advice, then then again, risk benefit, that's probably fine, isn't it? You probably do need it. Or if it was given from medical reason because you had low vitamin D, then that's good and that's fine. If you're just given it because, oh yeah, it's a good idea, you're, you know, you're 65 now, I'll give you some calcium supplements. I would say that's not a good reason to be on them. And maybe you should be referred for a sort of, you know, like a bone scan or something like that to prove whether you have osteoporosis and whether you whether you need it or not is what I say to patients. Yeah. The risk is that some some supplements have got calcium in them as well. So they combine calcium and vitamin D together. And so calcium supplements are definitely bad for kidney stones. There's no two ways about that because for the reasons we said earlier, you know, you want normal calcium, but calcium supplements are going to are going to put you up quite a long way, I think, because you get you should get your 1000 milligrams or whatever it is relatively easy in your diet unless you're, you know, unless you've got a very strange diet or something. So you would get that.
Dr Nish Bedy: Well, that's quite easy with with dairy, isn't it?
Dr Matthew Bultitude: Yeah. So if you're not if you don't have dairy, then then yeah. Um, so if you take calcium supplements, I think what I say to patients is there's got to be a good reason why you take it. And there are good reasons. You know, people get osteoporosis, um, risk of fractures from that. And that's, you know, a 10 to 15 year risk, isn't it? Which is which is improved with calcium supplements. But it's that risk benefit ratio. And I'm as a urologist, I'm not here to try and judge what your individual risk is for osteoporosis and getting um, uh, and getting or potentially fractures from it. But I can advise you on the fact that this is increases your risk of getting kidney stones by being on the supplement. So then you've got to work out with whoever prescribed it, where that benefit is. If it was given just because, oh yeah, it's a good idea, you're, you know, you're 65 now, I'll give you some calcium supplements. I would say that's not a good reason to be on them. And maybe you should be referred for a sort of, you know, like a bone scan or something like that to prove whether you have osteoporosis and whether you whether you need it or not is what I say to patients. Yeah. In the situation where you are told you should or you you do need to take it, there's a definite benefit to taking your calcium supplements with meals. And that's because like we've already talked about, the calcium when it goes in with your meal, binds the oxalate from that meal in the gut. So some of that then comes out as as calcium oxalate in your feces and doesn't get absorbed. So if you don't do it at that time, then you're getting your more calcium being absorbed because you're taking it outside meal times and you're not binding it with the oxalate, which is also then being absorbed at meal times. So you're definitely increasing your risk of getting kidney stone formation by doing that.
Dr Rupy: Yeah. If you think about that 24-hour time period and you've got these spikes of different things. So I'm having a big uh rich meal of spinach, my oxalate level goes up there. And then I I take my calcium later on that day and I have a big spike of calcium, you're not giving the opportunity for the calcium and oxalate to bind and be naturally processed through feces. So I I guess that's like that's that's generally good advice. If you have a genuine indication for taking calcium supplements. I won't ask you to go into calcium homeostasis here, but low vitamin D, why would low vitamin if I had a naturally low vitamin D, why would that be uh a risk factor for renal stones?
Dr Matthew Bultitude: Because parathyroid hormone controls is involved in controlling um vitamin D and calcium. And so when you've got a low vitamin D, your parathyroid hormone goes up to try and compensate for that. And by doing that, it generates it generates more calcium protection in the body. So it increases your amount of calcium. Yeah. So therefore, you get a high calcium and therefore increase risk of kidney stones. So if you correct the vitamin D, if it's low, you increase it, you bring down your parathyroid hormone and then you so then you you correct the calcium. And we see that sometimes in blood tests. You do it and the calcium is a little bit high. Um, and that's because of that you then need to check to see the vitamin D because maybe it's the vitamin D that's the problem and they do need vitamin D.
Dr Rupy: Yeah. Great. I said I wasn't going to ask you about that, but you did. That's right. That's right. Yeah, yeah. No, that's right. Yeah. Yeah. Um, what I I did I did find some stuff on on particular uh types of microbes that degrade oxalate, but there isn't too much evidence around that. And the last paper I saw was literally like eight years ago, but I think it's sort of uh one of these spaces which is like watch this space because I I think there's going to be a lot more um uh research looking at particular types of microbes that will degrade uh oxalates in your in your gut. Um, so that's definitely. I mean, a high fiber diet is recommended as that, you know, it could be for a whole bunch of things, but um, it might be related to the fact that it's improving your microbiota, um, which can improve uh the oxalate balance. But uh, in terms of other supplements that we are aware of that have a potential beneficial effect, what what are the ones are there? We've talked about um, uh vitamin D and and.
Dr Matthew Bultitude: So, I mean, the other thing people take about, I don't know about benefit, but risk, um, is protein supplements. Well, yeah. So protein build up drinks. I go to the gym, I need to do this. Um, and I universally say that that increases your risk of kidney stones. So people with kidney stones should avoid them.
Dr Rupy: Yeah.
Dr Nish Bedy: Yeah, I think it's quite common actually to see like maybe someone who's going to for weight gain, like um muscle size and things. So it's going to the gym a lot and being quite built up to have uh kidney stones now. So and that's, you know, you could say that's quite likely to be related to the supplements.
Dr Matthew Bultitude: Yeah. And there's clear evidence that that's that is bad. So, um, some people don't like it because obviously they do it and they want to build up their muscles and they say they need it because they're doing it all. And I tell them they need to go and see a dietitian or a nutritionist in that situation because I can't advise you then. But in general, protein build up drinks and shakes are bad for kidney stones.
Dr Rupy: Okay, fine. Because they're being marketed pretty heavily, I think these days, particularly to men who are more at risk of of kidney stones in general. Um, and is it because of the uh excess amount of purines that would lead to acidification in in the in the kidneys? Is that the general?
Dr Nish Bedy: Yeah, I think it's the the sort of amino acids particularly in um the animal protein that will end up then acidifying your urine.
Dr Rupy: Okay. If it was a vegan protein, I know we.
Dr Nish Bedy: So I don't think it has the same effect, but it doesn't mean that I can therefore particularly recommend vegan protein. I don't know if there's any other risks with it, but it wouldn't have that effect. I know for sure.
Dr Rupy: Yeah, because they're generally derived from like peas, brown rice, um, hemp.
Dr Matthew Bultitude: But that's not what people are taking, is I don't think, are they for gym supplements?
Dr Rupy: Oh, yeah, it's becoming a trend. I think as more people move to more flexi and plant-based diets, these types of powders are becoming a lot more popular. But I I guess they don't have.
Dr Nish Bedy: Because the typical ones are whey protein, aren't they? Which is kind of.
Dr Rupy: The typical one, yeah, traditionally the incumbents are whey from dairy. Yeah.
Dr Matthew Bultitude: Yeah. And people try to argue that with me and say it's it's whey, that's fine. And it's definitely not because I then I then went away and I thought I'll just check that. And it definitely does increase your risk as well.
Dr Rupy: Okay. Fine.
Dr Matthew Bultitude: Um, intuitively, I think you're you're your other sort of vegetarian vegan supplements are probably fine intuitively.
Dr Nish Bedy: That's what I think as well, but it's one of those where you don't know if you can really recommend it because I don't know if there's any evidence for that.
Dr Rupy: Yeah, I think it's also, you know, looking at your total protein consumption and actually seeing whether a supplement of protein is even necessary. Uh, because I think most people are obsessed with protein and actually they should be more concerned with the quality of their diet, the amount of fiber in their diet and making sure they don't have all the other additives like sugar and excess sodium.
Dr Matthew Bultitude: That's right. And I think if you're getting kidney stones and then you're thinking about that, that's when you need to get advice on that. And I say as urologists, we can't do that.
Dr Rupy: Yeah, yeah. Yeah. There are a bunch of other supplements that you can find, particularly expensive ones, uh, that are, you know, shown or, you know, claimed to to be beneficial for for different types of.
Dr Nish Bedy: I mean, I looked at just this briefly online to for the purposes of this talk really or this um discussion. And from what I could see in in the terms of what they contained, a lot of them just didn't seem to have anything, you know, anything that I would recognize as helpful for for reducing stones. But um, you know, that's I think that's the problem with supplements, isn't it? There's not really a regulated area, is it? Um, and I think.
Dr Matthew Bultitude: Yeah, it's not a regulated area. So I did I did research this a little bit for a talk last year. Yeah. So there is very little evidence for any of it. And of course, people are going to say, well, just because you haven't studied it and you, you know, you medics don't like, you know, only rely on evidence, you don't want to look at it because it goes against your traditional medicines. Sure, but if it was that good, then people would have done it because drug companies and everyone would pick it up and go, we're going to we're going to make money out of this. So I well, so so there's very little, so first of all, I think people need to be aware there's very little evidence. You also don't know what harm you're doing. You don't know what's in these things. Um, and probably less so with kidney stone um, supplements that you find, but certainly there's a lot of supplements for um erectile dysfunction, for um muscle muscle building and things. And a lot of those are adulterated with other drugs. And there was something like a quite a high figure of amount of supplements, particularly in those areas, where it's adulterated with common drugs that we use. So all sorts of things, steroids, a whole good. And that's how they work. And some of them have got Viagra in them. So they don't they don't say it on the label, but that's of course how they work. So people take them and think, oh yeah, this great herbal medicine that I pay 30 pounds a month for, it's really helping my erections. But actually, it's because it's got one of the drugs that you prescribe for it in it. So that's why. So I think that's less so with kidney stones, but there's definitely a risk of what what is actually in that. Second thing I say is just be careful because somebody is making money out of this. This isn't for free. So someone somewhere is making money out of being able to market this to you with pretty outrageous claims on some of them about what they do. And it's and it's not based on good evidence because there's very little evidence. There's like, you know, hundreds, you know, hundreds of these things. Um, loads of different products, loads of different things mixed up. Some of which actually do the opposite. So some quite a lot of them have got cranberry in them. Cranberry is thought to be a good thing for the urinary tract. People take it for urinary tract infections, slightly acidifies your urine if anything. But actually that's probably bad for kidney stones. So, but it's marketed as being, you know, specific for the urinary tract because it's got cranberry in it. But it might be, but it's not good for kidney stones. So.
Dr Nish Bedy: And I I always thought like I look at one paper like I saw which was looking at they just took a whole bunch of, I think it was cranberry or or some particular compound which said it had a certain amount, like one gram of this in each uh in each packet. And the amount that actually was contained varied between each packet. And then even within the packet itself, between the different tablets, there was a big variation in the actual amount. So I was like, well, you know, if you're taking this, you've got no idea really what you're you're actually achieving because like you said, it's not regulated. So.
Dr Matthew Bultitude: Yeah. No regulation is there. So yeah. So there's lots of things and people do come in taking these things. So, you know, I've had some pain, been to A&E, been diagnosed with a kidney stone, online, and then come in with various different things. One of them is called Chanca Piedra, which is also known as stone breaker. That's one of the common things that we've seen. Tiny little bit of evidence when I looked that up, but not very much. And some of it's negative. Quite a lot of side effects in some of the studies with that. So that's that's a herb that's found.
Dr Rupy: What's it called? Sorry?
Dr Matthew Bultitude: Chanca Piedra or stone breaker. Or Quebra Piedra as well. It's got various different names.
Dr Rupy: Is that is that derived from a plant or a root or something?
Dr Matthew Bultitude: Yeah, from about yeah, the leaf, I think. Yeah. Yeah. Um, and the trouble is with small ureteric stones, small ureteric stones tend to pass. So if you do nothing, they pass. You drink water, they pass. You stand on your head, they pass. You take this this herbal medicine, they pass. And then you go, oh look, I swear this worked because I passed my stone. So it isn't really proof unless someone does a proper study. And that and that's the problem with it. The other common one is apple cider vinegar. No human, no studies in humans at all. Nothing at all in humans to show that that works. There's some I found one animal study that showed a very tiny alteration in the acidity of the urine and tried to justify that as therefore it prevents stones. As in, did it alkalize the urine? I think it's tiny. It was a I presume so, but it was a tiny amount. So actually, but if it was that good, someone's going to someone's going to do it. So, you know, um, I yeah, I think you just got to be careful and you know, there are horror stories, aren't there from, you know, over the years of herbal medicines that go wrong as well. And are then years down the line found to have uh to have, you know, cancer forming properties and stuff like that. So just be very careful with what you're taking because there will almost certainly be no evidence for that sort of thing. The type of things you then find online to about alkalization may well do for the reasons we said, that may well be reasonable. But it's just the problem is finding finding the one that is actually good and is has got the right amount of alkali in it to to do to have the desired thing. And therefore you should probably be measuring your pH to that sort of joins this whole conversation up, doesn't it? If you're going to do it, you should measure your pH to see rather than just taking a tablet and going, oh well, I'm on this thing from Amazon and it must be preventing my stones.
Dr Rupy: Yeah. And I think also with regards to checking your pH, if you don't know what type of stone you have, that can also not be beneficial as well. So you need to make sure that you have all the the information correctly before you start doing all these things.
Dr Nish Bedy: And alkalization um, like which could be done with other uh medications or other supplements that may have sodium in them because sodium bicarbonate is quite a common one. Then that may have a knock on effect of increasing your calcium in your urine. So it's not necessarily just alkalization itself as well. So it's just about, yeah.
Dr Rupy: Yeah. Yeah. Being getting the right thing, I guess. Yeah. Um, any other supplements that are positive or have we covered all of those? Can you offer that list? Is that the one that works?
Dr Matthew Bultitude: But there aren't. There's nothing we we recommend to patients, is there? So I don't think there is anything that is.
Dr Rupy: Not for this. Well, I think there's like water is a supplement. And it's free from a tap. Yeah, yeah. I think we've covered a lot of things that people can do to make sure they're not at risk of a stone if they have anything in their family history or if they have a recurrent stone as well. And I think if a lot of people did that, I mean, I I I read something uh about just fluid, uh hydrating yourself appropriately can reduce the recurrence up to 30%. Is that right? For certain types of stones, I guess.
Dr Nish Bedy: Yeah, I think that's the the evidence that's kind of in the in the Bouse leaflets even, I think something like 30%.
Dr Matthew Bultitude: Yeah. The figure I quote is two liters, more than if you can reliably make two liters of urine coming out every day, that might be difficult every day, you reduce your risk by 20%. That's the figure I quote from one of the papers. So but that's in the same ballpark, isn't it? 20 to 30%.
Dr Rupy: Yeah. Brilliant. That's awesome. Well, I think we've uh we've covered a lot on kidney stones. Bar the surgical intervention. But I'll let you guys chat about that afterwards.
Dr Matthew Bultitude: Surgeons, we love operating. So don't do any of what we said. Yeah, yeah, yeah.
