#301 Anticancer Diet, Lifestyle and Supplements with the UK’s First NHS Integrative Oncologist Professor Robert Thomas

11th Jun 2025

Up to 40% of cancers are attributable to modifiable risk factors, including diet, obesity, alcohol, tobacco use, and physical inactivity.

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The WCRF estimates that around 1 in 3 cancer cases in high-income countries could be prevented through healthier diets, maintaining a healthy weight, and regular physical activity. And according to the National Cancer Institute in the US, physical inactivity is a recognised risk factor for colon, breast, and endometrial cancer.

But even with the best intentions, there’s a lot of confusion around lifestyle and cancer. One day it’s red meat, the next it’s microwaves. We hear about them in headlines, social media posts, or passed around in conversation – which can make it really hard to know what matters most.

I’m joined today by Professor Robert Thomas, an NHS oncologist and researcher who’s spent decades studying how lifestyle (from food and movement to gut health and supplements) affects cancer risk and recovery.

He was recently appointed Head of Integrative Oncology at The Royal London Hospital for Integrative Medicine, making him the UK’s first NHS Integrative Oncologist. This complements his existing role as an NHS Consultant Oncologist at Addenbrooke’s and Bedford Hospitals. He is also a Clinical Teacher at the University of Cambridge. At the start of our conversation, we talk about his new role and the types of patients he works with.

View the podcast on our YouTube Channel

Books: How to Live, Keeping Healthy with Cancer

You can find out more from Professor Thomas on his YouTube channel: https://www.youtube.com/@ProfThomasMD

We talk about:

  • Anticancer diets – what to eat to reduce your risk
  • Gut health & cancer – the powerful connection between your microbiome and cancer Inflammation & risk – how chronic inflammation increases cancer susceptibility 
  • Exercise & cancer – the science behind how movement helps fight cancer cells
  • Microplastics & personal care products – the hidden risks in everyday items
  • Aluminium in makeup & deodorants – investigating the potential health impacts
  • Fertility impact – how lifestyle and environmental exposures may affect reproductive health

Episode guests

Professor Robert Thomas

Professor Robert Thomas is a NHS Consultant Oncologist at Addenbrooke's and Bedford and  Hospitals. He is also a Clinical Teacher at Cambridge University, the health journalist for National World News, a colomist for the DailyMail, a Professor of Sports and Nutritional science at the University of Bedfordshire and author of the bestselling book "How to Live"

He was recently appointed Head of Integrative Oncology at The Royal London Hospital for Integrative Medicine, where he advices self care, lifestyle, complementary and nutritional strategies which aim to help well being and improve outcomes.

At Cambridge and Bedford, he manages patients with chemotherapy, hormonal, radiotherapy and biological treatments. He also leads a Lifestyle and Cancer Research Unit which designs university approved scientific national studies that evaluate the impact of exercise, diet, gut health and natural therapies on cancer, long covid, other chronic diseases and exercise performance. He is currently chief investigator of the national covid vaccine nutritional intervention study and the UK YourPhyto study which was the World's first clinical evaluation to show that an intervention to improve gut health (Yourgutplus) combined with a phytochemical rich supplement (Yourphyto) slowed prostate cancer progression, improved urinary symptoms, reduced markers of inflammation and improved overall strength. His over 100 peer viewed scientific papers and presentations published from this research, can be accessed on cancernet.co.uk/rthomas.htm.

For this work, he has been awarded the Royal College of Radiologist and Oncologist research medal, an honorary Fellowship at the British Society of Lifestyle Medicine,  and "Oncologist of the Year" by The British Oncology Association.

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Podcast transcript

Dr Rupy: Does sugar cause cancer?

Professor Robert Thomas: Indirectly, yes.

Dr Rupy: Interesting. Okay. Can diet prevent me from getting cancer?

Professor Robert Thomas: Yes, it can reduce the risk considerably.

Dr Rupy: Can a poor diet impact cancer treatment?

Professor Robert Thomas: I believe so. It will certainly increase the side effects and reduce the risk of it being curative.

Dr Rupy: Okay. Can everyday products like cleaning products and deodorant raise cancer risk?

Professor Robert Thomas: The evidence is suggesting very much yes, and they're increasing a lot in our environment. So the amount of exposure we get is going up year by year.

Dr Rupy: Can fasting help lower the risk of cancer?

Professor Robert Thomas: That's a more difficult one. I do believe that fasting has a strong place in lifestyle medicine. It can certainly improve wellbeing and gut health and all these other things. There's not been a single publication to say that if you fast, you would have a lower risk of cancer, but I believe the answer would be yes, actually.

Dr Rupy: Is it true that most cancers are not caused by genes?

Professor Robert Thomas: It's about 50/50. So it's not true that most cancers are caused by genes.

Dr Rupy: Okay. All right.

Hi, I'm Dr Rupy. I'm a medical doctor and nutritionist. And when I suffered a heart condition years ago, I was able to reverse it with diet and lifestyle. This opened up my eyes to the world of food as medicine to improve our health. On this podcast, I discuss ways in which you can use nutrition and lifestyle to improve your own wellbeing every day. I speak with expert guests and we lean into the science, but whilst making it as practical and as easy as possible so you can take steps to change your life today. Welcome to the Doctor's Kitchen podcast.

Up to 40% of cancers are attributable to modifiable risk factors, including diet, obesity, alcohol, tobacco use, and physical inactivity. But even with the best intentions, there is a lot of confusion around lifestyle and cancer. One day it's red meat, the next it's microwaves, what about sugar? You hear about them in the headlines, social media posts, or passed around in conversation, which can make it really hard to know what matters most.

Today, I'm joined by Professor Robert Thomas, an NHS oncologist and researcher who spent decades studying how lifestyle, everything from food, movement to gut health and supplements, affects cancer risk and recovery. Today, we're going to talk about common cancer myths, things like mushrooms and herbs, anti-cancer diets, and what to eat to reduce your risk, gut health and cancer, inflammation and cancer risk, exercise and the mechanisms behind how exercise and movement in general fights cancer cells, things like microplastics and personal care products and what the real hidden risks are in everyday items, including aluminium and other things like deodorants. We also touch on fertility impacts too.

Professor Robert Thomas was recently appointed Head of Integrative Oncology at the Royal London Hospital for Integrative Medicine, making him the UK's first NHS integrative oncologist to complement his existing role as an NHS consultant oncologist at Addenbrooke's and Bedford Hospitals. He's also a clinical teacher at Cambridge University. And at the start of our conversation, I wanted to dive in a little bit more about his new role and the types of patients he encounters as referrals. I really hope that this episode is going to serve to empower you, the listener, to prevent this disease that is becoming so much more common, especially in younger populations, and particularly in the UK and the US. We do touch on some of these statistics during today as well. But also, if you're going through cancer, you know someone who's going through cancer, or you've been through cancer yourself or someone in your family or loved ones and want to prevent recurrence, I really want this episode to serve as a reminder of just how much control you have and an information resource.

I'm a really big fan of Professor's books. You can find How to Live and Keep Healthy After Cancer in all good book stores. You can find the links to those in the podcast show notes, and you can also find out a lot more about Professor on his YouTube channel, which I've linked in the podcast show notes as well.

Just for reference, at the end of the pod, we talk about his latest study looking at a phytochemical-rich supplement combined with a probiotic and its impact on low-grade prostate cancer. I want to make it clear that neither I nor Professor have a commercial affiliation with this company. The company is called Your Fyto. They donated their products and they went through a rigorous tendering process for this research study, but in no way am I affiliated or Professor Robert Thomas affiliated with the company commercially.

Appreciate you coming back on the pod. It's been a couple of years. Why don't we start off by talking about what we mean by cancer? Because I think people think cancer to be one thing, whereas actually it's a bit of a catch-all term, I find. So when you explain what cancer is to folks in clinic, how do you describe it?

Professor Robert Thomas: You're right, cancer is not one thing. I mean, it's a diverse set of diseases. Even within the same organ, such as breast, there are genetic changes in the cancers which which are which make it completely different in terms of treatments, outcomes and cure rates and things. So you're right to bring this up. But put in a nutshell, if some a patient says to me, what is cancer? Because it's effectively your own cells which have gone wrong. The genetic precursors for cancer are already in our genes. And that's why your first question, is it nature or nurture? They are already in our genes, but through bad luck or lifestyle, the way we choose to what we choose to eat, mutations occur in our DNA, which rearranges them, and then genes which were previously suppressed get activated. And when they're activated, instead of a normal cell growing to a certain size and then stopping growing or or dying through a process called apoptosis, that then that cell then says, look, I don't want to die now. I want to I want to carry on growing. A bit like a virus, they want to grow as fast as possible, spread into adjacent organs, and then spread to other parts of your body. And that's what the damaging part is. They're replacing your own cells and damaging your own cells. And ultimately, that's what becomes the fatal part of getting cancer.

Dr Rupy: Okay. So when people die from cancer, is it true that we're not really talking about the primary site, the tumor itself, it's the knock-on effect of having all these cells proliferating throughout the body?

Professor Robert Thomas: Yeah, there's a number of facts. Some cells, actually cancer cells can produce hormones and chemicals which can be damaging, and they're sort of hormonal type things. And and those chemicals can then go on to cause failure in other organs. The other part is what you've just said, the the the sheer weight of cells which aren't dying when they ought to, spreading into say the bone marrow, causing bone marrow failure, knocking off tubes from the kidney, causing kidney failure, going into the liver and replacing the normal liver cells with cancer cells, meaning that patient will then die of liver disease, can spread to the brain, and you know, you'll you'll get fitting or you eventually stop breathing. So it's actually the physical impact of having these cells which shouldn't be there is the problem.

Dr Rupy: Since we last spoke, you've actually started a pretty phenomenal position that's a UK first from from my understanding. Can you tell us a bit about that?

Professor Robert Thomas: So two days a week, I've been lucky enough to be appointed as head of integrative oncology at the Royal London Hospital for integrative medicine, which is at Great Portland Street. And three days, I'm still a mainstream oncologist giving chemotherapy, radiotherapy, biological treatments, hormones, etc. So that is a an actual first. Many people will call themselves integrative doctors or integrative nutritionists or integrative oncologists even, but this is the first post where there has actually been a full-time working oncologist doing integrative oncology, which is which I really enjoy and it's given me an opportunity to really sort of get into the subject a lot deeper.

Dr Rupy: Yeah, because you've really been at the forefront of, from my position anyway, you've really been at the forefront pushing diet, lifestyle, and in certain cases, you know, certain supplements and other practices to the forefront of what we should be doing when it comes to cancer prevention and during treatment as well. So walk us through what that position actually enables you to do on the on those two days a week.

Professor Robert Thomas: Well, yes, as you say, we've been doing trials on lifestyle for over 25 years when it wasn't actually trendy to do so. Now, it is. So for me, it's great to be able to be in a position, an NHS position where I can actually spend much more time with patients and go through factors which will help them overcome their cancers, help their improve the cure rates, reduce the side effects, and guide them through strategies which may not be appropriate, which they've gone into. So it's, you know, it's it's very fulfilling and, you know, I just wish there were more posts like that around the world.

Dr Rupy: Yeah, yeah, it's pretty phenomenal. And so walk us through what you might be doing in one of these clinics on a typical day. Give us a bit of an insight. If I was a fly on the wall during one of your consults, what that actually look like?

Professor Robert Thomas: Well, for the post as a whole, what we're trying to do is educate oncologists around us. There's still a lot of patients being told there's nothing you can do to help yourself. And the data is very much against that. There's lots and lots of papers to show that people who look after themselves with, you know, eating food like you're advocating, exercising, they do better, not just better cure rates, they have lower relapse rate and they have less side effects. So it's it's and a lot of oncologists don't know that. So part of the role is to give talks around the country, talk to your colleagues to try to persuade them into sort of lifestyle medicine. So that's the the global position. On a for clinics themselves, the patients are split up into really four different types. There's there's some which are refusing medical treatments with curable tumors. And fortunately, that's less than 5%. And that's very sad. You know, I saw someone last week with a, you know, she's actually in the medical profession with a with a 1 centimeter breast tumor, 90% chance of cure, refusing even surgery. So, um, a lot of that is about trying to explore what the underlying fear for cancer treatments are and and try to wiggle that out and offer them guidance. The second group is say you've had your initial treatments such as surgery or even radiotherapy, and the oncologist is saying you need these adjuvant treatments which could make them postmenopausal or require long-term chemotherapy or biological treatments which have significant side effects. And then going through relative risks and and using packages like predict NHS for breast and prostate or on type DX, which are genetic tests, and saying, well, actually, you know, you've got a point. You've only got a 1% benefit from chemo. So maybe we should go together, go back to your oncologist and say, you would want to reduce your risk through other ways like, you know, not being overweight, exercising, eating healthy foods, or the other side of the coin, they might have a tumor which really does need the treatment and then you're then trying to persuade them to have them. Okay. And then the other group are people with who are on ongoing treatments and they're suffering greatly, either at that moment or after treatment is finished. So they might have menopausal problems and dealing with joint pains, mood changes, weight gain, you know, vaginal dryness, anything, peripheral neuropathy, fatigue. So, you know, the list is endless of the side effects of cancer treatment. And ways they can they can recover quicker or diminish the impact of those side effects. And then the other group, and these aren't mutually exclusive, by the way. The other group would be, you know, people who have ongoing cancer, they're not going to be cured, but maybe they're doing okay on treatment, but we want to make that treatment work better and have less side effects so they can live for longer at a good quality of life. So, you know, it's it's immensely rewarding.

Dr Rupy: It's from the sounds of things as you're explaining to me, it's almost like a a secondary opinion service with someone who is really up to date with diet, lifestyle, and just assessing the need or the true need for some of the treatments that their existing oncologists have have recommended.

Professor Robert Thomas: Well, that's the advantage of being an oncologist as well, is you can actually dip into their main treatment a lot more integratively, which is what the name implies. Uh, some oncologists, of course, see that as a bit of a threat, but most don't. You know, they're happy to have a dialogue. Ultimately, it's their decision what what happens between them and the patient. Um, but also, the other end of the coin, there's a lot of people come already with a long list of um interventions, complementary therapies, some of which are actually totally inappropriate, might be doing themselves harm, but they've just gone down a blind alley of Googling everything and, you know, they're on multiple different mushroom complexes and rare herbs from Tibet and and probably all counterbalancing each other and causing harm. So, uh, you know, it's it's it's to sort of try to steer them in the right direction.

Dr Rupy: And and this is why I think a service like this is so important because it's very easy to dismiss some of these ideas that people have and, you know, the rabbit holes that they've taken themselves down with herbs and mushroom complexes, etc. There's probably like a modicum of truth in some of the things that they've come across, but perhaps it's just being approached in the wrong way and it requires like a a sound reasonable approach. But a lot of people might have felt dismissed, you know, in previous consults. I know certainly during my tenure as a junior doctor, we came across many of these types of patients, in you know, not necessarily oncology patients, but in other specialties. And it was almost part of the culture to dismiss these patients, um, you know, heart-sink patients, whatever you want to call them. And and I think the tide is turning on this quite a bit. Um, would you say?

Professor Robert Thomas: I love the word heart-sink patients, so I do feel I specialize in heart-sink patients, but I like that challenge, but other people may not, by the way. Uh, yeah, I mean a lot of it is is um, I don't want to criticize my doctor colleagues, but a lot of them dismiss patients and they don't know the data. You know, I saw a patient from the city who's he was a CEO of a big bank. He said the worst thing which he was told during his cancer pathway is there's nothing he can do to help himself. And you know, even and there is, but even if it if if if there isn't, I mean to tell someone that, especially a powerful man who wanted to have some control of his destiny. And uh, you know, he came came to us and we said, look, of course there is. I can show you 10 papers tomorrow. Most of them, you know, every journal you read now, there's more and more evidence coming that you can alter your destiny. You can't have 100% control, but you can statistically change your odds. Um, so it's it's, you know, that's a very important factor in itself. Um, but also people are told, you know, don't take, don't I was had someone the other day, don't take kimchi during chemotherapy because there's bacteria in kimchi. You know, probably the worst advice you can have, you know, you really need to look after your gut during chemotherapy. So it's uh, you know, it's every single patient there's something you can help with. And a lot of it is obvious. Yeah. And they've been told by their current doctors completely opposite. And the impact of dismissing them means they then, as you say, go down a rabbit hole and then they end up with lots and lots of things which are, you know, working against each other. Yeah. Yeah. Another example, you know, there was someone was on was taking selenium, magnesium, zinc, copper, all different supplements costing a fortune. I said, well, why don't you just take one mineral supplement with it all in? You know, that will at least save you 30 or 40 pound. So you can actually save them money as well and just be more precise.

Dr Rupy: With the rise of wellbeing and and health conscious people, I'm imagining that you're going you're getting quite a few referrals. How are you dealing with this influx?

Professor Robert Thomas: Uh, well, there's there's a happy medium between getting enough referrals to have your clinics full, which was not a problem, and having too many and having a waiting list because the way the government funding is, if you've got a waiting list, you're not seeing them on time, the hospital gets gets penalized. So, uh, yeah, so your bosses are constantly saying, be be popular, but not too popular. Uh, but I suppose if if you then can, you know, you can then make a case that there are lots of people out there who need help, maybe they can change the funding pathways, but most hospitals are looking to reduce the amount of staff, not increase them. So it is a, you know, you're always fighting that battle.

Dr Rupy: Are there some complementary practices that you've come across during your career that you've sort of changed your mind on? Like initially you were like, that doesn't sound right at all. There's, you know, that doesn't sound like it would work or there's no particular mechanism behind that. It's not plausible. But actually, you've changed your mind on. Like as you mentioned mushrooms and some of these herbs and stuff like that, it just came to mind.

Professor Robert Thomas: Um, I've since I've started the post, I've actually had to do a lot more background reading and evidence research, I have to say. Mushrooms, for example, medicinal mushrooms is are very popular. Uh, there's a lot of products out there and I'm often asked by my colleagues at UCLH to sort of summarize the current data. And uh, for example, there is no double blind randomized trial of medicinal mushrooms in humans to show tangible clinical data. That said, there's quite a few, you know, animal studies and cell line studies which suggest a benefit, but so it's made me a bit more open-minded, but um, the problem is a lot of patients come looking at animal research, looking at cell line data and say, well, these things help. But we all know even for drugs, you know, a lot of them look good on in the lab, but they never um develop into good products. Um, so it's it's uh, I've become more open-minded. I don't want to dismiss people. Um, the main thing is also safety. Um, for example, medicinal mushrooms tend to be quite safe. Um, they are, you know, they're good for gut health. They I I do tend to encourage, you know, your recipes to cook with more mushrooms rather than go and take a mushroom supplement. But uh, yeah, it's it's it's a fine line. Um, there's no therapy out there um which I've suddenly thought, wow, this is amazing. I want to do a clinical trial on it. Okay. Uh, there's the off label or repurposed drugs seem to is a a little bit of a problem at the moment. Um, but then I often point out the data that things like metformin, aspirin, probably aspirin is the most common repurposed drug and there is some benefit for that. Um, saying that, if you have anti-inflammatory foods, like you're advocating, um, you probably have the same benefit as taking an aspirin and and more. Um, metformin probably only works for people who are pre-diabetic. So I sometimes work with their GPs to say, look, do a hemoglobin A1C, if they're borderline, maybe have a lower threshold to start something like metformin. But then the anti-helminths and the statins and and and the antihistamines, I'm looking at the data and not particularly impressed with it. And a lot of people are going on them um with the hope that it could improve cure rates, but I'm I'm concerned it might actually be doing more harm than good. But again, keeping an open mind.

Dr Rupy: Yeah. Just to clarify for the listeners, you mentioned HBA1C, which is a blood marker that is used um very commonly in primary care as a snapshot picture of your blood sugar average over the preceding 90 days or so. And it's something that we use as part of the diagnosis of pre-diabetes, which is the stage before type two diabetes where your sugar regulation is um out of whack. Um, on that on that note about an anti-inflammatory diet, um, is there such thing as an anti-cancer diet? And if so, what does that look like as a means to prevent cancer?

Professor Robert Thomas: Um, well, have you got two hours? We've got we've got more. Um, yeah, if you want to call it an anti-inflammatory diet. The the nice thing about um being an oncologist, when you talk about diet, these diets don't just help cancer. They, you know, they help everything. You know, they they would help reduce the risk of arthritis, dementia, diabetes, weight gain, osteoporosis. So I wouldn't more put it, yes, there is a healthy diet which helps a number of disease. Um, and you you need to split it up, I suppose, into what foods are promote cancer, what could drive cancer, and what foods could help your body protect you from cancer. So if you if you look at the unhealthy foods first, so there's clearly a lot of evidence for processed meats, ultra processed foods, which are full of, you know, chemicals, sugar, artificial sweeteners, which destroy gut health, um, and cause inflammation. Um, and particularly the processed meats, you know, the the cheap meats, tin meats, etc. Um, sugar, I would definitely say put in the list of cancer promoting foods, not because sugar directly drives cancer cells, because sugar damages gut health, um, and if you have poor gut health, toxins go into your body, your body reacts against it and increases inflammation. And it's a strange quirk of evolution that if we have too much inflammation in our body, um, it causes cells to divide faster. And when cells divide faster, they don't have time to repair their genetic mutations, they create more free radicals, which then damages further DNA. So yes, there's a knock-on effect of sugar, but, you know, reducing sugar to an absolute minimum isn't going to be the answer. And then on the other side of the coin, what foods then enhance your gut health and reduce inflammation. So these would be your phytochemical rich foods, broccoli, herbs, spices, tomatoes, berries. And they feed the healthy bacteria, improve gut health, reduce the leaky gut, if you want to use that term, reduce inflammation in your body. And they also have other direct anti-cancer benefits. So for example, they upregulate antioxidant pathways. And antioxidants are the things which mop up excess things like free radicals or other things which damage DNA. Uh, they have direct anti-cancer properties such as reduce excess proliferation, and they can even do things like help the expression of certain genes which promote cancer, it's called epigenetics, which is a big field at the moment. Uh, so they have, so the more of those sort of foods you have, the better. And then on the same side of that, having things like fermented foods, foods with lots of healthy bacteria will also support the gut health. So that's it in in a nutshell, but we can go on and on and on.

Dr Rupy: So I just want to pull up a a few things here. Um, gut health is obviously very important to the prevention of cancer. When we say gut health, what do we what do you mean and and how do you explain that to patients when you say looking after your gut health? And why is gut health so important as a means to prevent cancer? And forgive me if you've got to repeat yourself a couple of times, but I just want to make sure that the listener is getting really clear on why gut health is so important.

Professor Robert Thomas: Basically, um, if you have an inflamed leaky gut, um, it creates a number of problems. Inflammation within the gut is bad because it increases the risk of ulcers, indigestion, food not being absorbed well. So there's a higher instance of inflammatory bowel disease. And of course, inflammation in the gut cells increases the risk of local cancers. So there's an increased risk of bowel cancer, for example. Not only that, if your gut is not functioning well, and and the lay term is leaky gut, it's not actually a medical term, but we all know what it means. It means that the uh your your gut is allowing in toxins and pathogens into the bloodstream and allowing healthy nutritional elements such as minerals and um vitamins to leak out and protein sometimes in severe cases. So when you when you've triggered when those increased toxins go into the bloodstream, your body elicits an immune reaction against it. So you're using up your immune pathways. And that creates this chronic inflammation. And a byproduct of your body trying to get rid of all these toxins which shouldn't be in there is it starts attacking its own cells because it's throwing out these defense mechanisms. And when you mean your own cells, it could be joints causing arthritis, it could be your brain causing brain fog or your heart increasing the risk of heart disease. And and again, for cancer, because inflammation through this quirk of nature causes cells to divide more, it's increasing the risk of cancer in multiple organs. So we know that gut health is linked to cancer in in many different parts of the body, as well as chronic degenerative diseases such as Parkinson's, dementia and things like that. So it is pretty much the cornerstone of ill health.

Dr Rupy: Yeah, and it's something that we weren't really talking about 10, 15 years ago. You know, now it's fashionable to talk about gut health, there's all these products out there, etc. Uh, I think even the idea of intestinal permeability is still somewhat controversial in certain fields because we lack sort of the the means to measure it accurately in lots of people. But, you know, for me it makes sense and as perhaps a a holistic-minded doctor, um, it it makes complete sense and I've seen this with patients and stuff. Um, but it it does seem somewhat controversial in in certain circles. Do you still get that pushback on this idea?

Professor Robert Thomas: Yes, I mean, during COVID, uh, when we had to stop all our medical trials, we the first thing we did was a was a gut health and COVID study. And uh, we showed uh very obviously, and I wasn't surprised by the results that if you did an intervention in that case with a probiotic and vitamin D which improved gut health, people's COVID symptoms significantly diminished. And there's been three or four other trials around the world all showing the same thing, which is very reassuring. But you're right, before, you know, when we were putting the proposals to the government to say we need to improve gut health to reduce COVID, they were not even considered. We had to use this anti-helminth which we all had to do and it came out completely negative. Um, but you're right. So even with cancer, although there's a strong correlation looking retrospectively at data, there's very few prospective or randomized trials. That's why we went on to do some of those trials. Uh, but you say that, um, uh, but now with the new biological treatments, I'm sure you know this data, which work by recruiting your own immunity to to find the cancer cell and kill it. If your own immunity isn't working so well, um, they don't work as well. And there's lots of published data now from good institutions such as MD Anderson in Texas, which show that uh these things called PDL1 inhibitors, which is the main category of immunotherapies, which we're all using and they're brilliant drugs, they work uh 40% better in patients with good gut health. So, I mean, that's an amazing fact. So they're now doing prehabilitation programs to people starting these drugs to improve the gut health so the gut the drugs work better. Oh, wow. Unfortunately, that's not happening a lot in Britain. It's it's very sporadic. In my center, we always do it. Uh, but around Britain, it's not done that well. Uh, but in America now, in the large institution, it's it's a it's a prerequisite before starting them because you'll get a better chance of response. Also, you get more side effects if your immune system's all over the place. You're more likely to get lung toxicity, joint pains, diarrhea. So, um, you know, it's safer to improve gut health. And the president of ASCO, for example, stood up a couple of years ago and said, we need, this is what we need to be directing research at. And the pharmaceutical industry is also actually, you know, the one examples are also supporting lifestyle medicine because they think, hang on a minute, these are 80,000 pounds a year. Now you do the maths, you know, if you've got 40% response rates, these people are going to be on it for another two or three years. You know, you're talking billions of extra profit for drug companies if people are healthier. So it's an all-win situation for everyone. And hopefully that money will get recirculated, they'll pay taxes and we can start building hospitals. But uh, yeah, so it's it is it is definitely a field which is evolving rapidly, not fast enough in my opinion, but it is evolving rapidly.

Dr Rupy: Yeah, because I'd love to talk about a prehab uh menu, you know, for anyone who is going through cancer, regardless of whether, you know, we're we're using immunotherapies or radiotherapy, etc, a combination of all the above, having a prehab menu to optimize your general wellbeing and yes, your gut as well. That that would be amazing. This is something that we should be promoting on the NHS.

Professor Robert Thomas: 100%. I mean, the Macmillan and the Royal College of Anesthetists did a prehab sort of brainstorming session and produced a document recently. They mainly just concentrated on exercise, which is also really important, of course. Um, and they they just felt the data needed a bit more robust sort of evidence for for it to to to start recommending. But I think it's there. And certainly, um, you know, as I say, in large American institutions, they're doing it. We already refer to dietitians sometimes, but they tend to look very much at have you been given some recent antibiotics and uh, very much mainstream. Right. And I think that could be taken further. I like you said, they they need to be, you know, you need someone to go into their house, look in their fridge, take out all the bad foods, get your cookery book, start making foods which are going to improve their gut health. No, you know, I'm joking, but it's actually true. You need to sit them down and say, this is what you need to do. And a lot of people don't understand, you know, they're still having sugary breakfast cereals. Half of them never heard of of sauerkraut or kimchi or kefir. So there's no sort of healthy bacteria in their diet, especially in the British diet. Um, so yeah, you know, I I think it it takes time, but I think that should be part of a integrative part of an oncology service.

Dr Rupy: Why do you think it's so controversial uh to say that we should be removing sugar from our diet and that sugar has links to cancer?

Professor Robert Thomas: It's less controversial now than when I first started going on about this. I mean, I was literally 10 years ago, I was giving talks and and dietitians were standing up and shouting at me saying, how dare you say that sugar is harmful? You know, you're you're you're making them anxious and and making them feel guilty about enjoying food. Um, so I then first of all, we did a systemic review of the evidence and published it. So I could actually then, you know, put on the table of the the critics and say, well, read that. There are at least 50 cohort studies which say show that people who eat more sugar in their diet have a higher risk of cancer, have higher cholesterol, have higher heart disease. And of course, at that time, remember we were all being told to eat less fat and and almost more sugary things instead. But that's been proven wrong as well. So it's about collecting the data and showing it to people in a nice way. And then since then, um, you know, there's been more studies coming out showing that there's there's strong links with inflammation, strong links with um, when you give cancer treatment, sort of the risk of high cholesterol goes up, risk of heart disease goes up. So it's strong list of subsequent problems after cancer treatments. But it's very hard to do a double blind randomized trial of say a population having no sugar and a population having high sugar. So that's the problem. And then some doctors would say, well, there's no randomized data, so there's no data, which is not true, but some people stick to that doctrine.

Dr Rupy: And looking at the other extreme, ketogenic diets have become quite popular in the weight loss industry. You know, some other people are utilizing ketogenic diets for therapy, um, you know, beyond treatment refractory epilepsy in pediatric patients. You know, we're seeing it being used in things like inflammatory bowel disease, other autoimmune conditions. Some some of whom are actually having some success with it. Um, but within cancer, it's it's a bit of a murky field. What are your top line thoughts on ketogenic diets?

Professor Robert Thomas: Um, well, I'm not trying to promote my book, but there is two there is a chapter exactly on this. It's quite complicated. Um, the purists actually cut out fruit and veg from their ketogenic diets, which which actually I don't advocate because those have got lots of phytochemicals. So that's my main problem with it. Um, also the underlying um hypothesis of why the ketogenic diet works is in my opinion, essentially flawed in many explanations about it. That said, it's actually quite healthy. So if you could do the ketogenic but keep your vegetables and some fruit, I think it's a pretty much a perfect diet. So I you know, I don't want to criticize it, especially if you're a bit overweight. Uh, and if you throw in some sensible fasting, such as overnight fasting, 13 hours and that sort of thing, I think it's very good for your health. So, uh, but, you know, some of the things that cancer cells can't uh can't feed off ketones and therefore if you you if you increase the ketones, they're going to die out is just fundamentally not true. But reducing your sugar, reducing processed carbohydrates, having periods where you're fasting is also very good. So I don't want to criticize it. Um, so I'll probably leave it there.

Dr Rupy: Are there certain cancers that would be more responsive to a ketogenic diet that you're aware of?

Professor Robert Thomas: Uh, well, things like pancreas and and gut are supposed to be more susceptible to it. Uh, I think it depends more on on the individual patient. So if you've got a pre-diabetic patient or someone who's overweight, um, then I think that you'd probably get more benefit.

Dr Rupy: Okay. And that could potentially be explained, I guess, by um sugar regulation as well generally. So reducing their fasting sugar levels and average sugar levels. Um, I want to talk a bit about the things that we should be taking out of our diet. Uh, just just pushing on this a little bit more. Acrylamides, nitrosamines, processed red meats. Uh, should we be removing all red meat from our diet? Is this something that would be advisable for everyone? Because this is what certainly a lot of people are pushing for looking at, you know, big population studies.

Professor Robert Thomas: Um, well, on an ethic perspective and an environmental perspective, we should be eating less meat. I mean, clearly, it's quite bad for the environment to have so much meat. Uh, on a health perspective, um, WHO did a very good sort of meta-analysis and worked out that meat three times a week is probably the optimum. You know, you're getting your B12, you're getting more proteins, you're getting minerals and things. Of course, it's very much meat is not just one thing. You could have a, you know, a grass-fed cow from the Shetlands who's eaten lush green grass. So it's the meat's got full of omega-3s and very few toxins would be healthy. Um, but then of course, you've got the processed meats or or cattle which has just been force-fed ultra-processed food, you're and, you know, hormones and chemicals and pesticides and herbicides. I mean, that's not going to be healthy either. All right. The more processing, the worse it is ultimately. Um, so yeah, I mean, try to eliminate all ultra-processed meat and ultra-processed plants for that matter. Limit it to one or two days a week or three at a push. Um, you know, and try to have more oily fish and things like that. That would that's where the evidence seems to be lying.

Dr Rupy: Okay, because I think there is and you'll hear this a lot from, you know, on social media, but certainly from from well-meaning uh academics and other doctors who are typically of a plant-based uh persuasion that any red meat in the diet is going to be pro-inflammatory and pro-carcinogenic and it is significant. So we should be removing it completely from one's diet. I personally take the sort of middle way here where, you know, you look at some of those big studies, like the one in JAMA, I think it was 2016, they found that actually, if you had red meat and an unhealthy behavior, that's where you see the pro-carcinogenic effect. But if you take away the unhealthy behavior, it appears to be neutralized.

Professor Robert Thomas: Yeah, that's exactly what the data is showing. If you have it excess or poor quality and you don't counterbalance it with herbs and spices, etc. Um, I mean, the the way meat becomes carcinogenic is is if you if you heat it to to high temperatures, you you you convert the amino acids into uh nitrosamines and and that's the thing which causes the cancer. Um, but there's lots of studies show if you have it with, you know, vitamin C rich foods or phytochemicals, those uh amines actually get converted into nitric oxide and then nitric oxide is actually a vasodilator, improves perfusion of your organs and your brain and improves sports performance. So it's what you eat it with. So if you're having a nice bit of good quality meat, make sure you've got lots and lots of vegetables, herbs and spices with it.

Dr Rupy: Okay. Um, pressing on with this prevention arm of our conversation, uh, microplastics and toxins in our atmosphere. I think a lot more people are becoming aware of microplastics. Um, what are your thoughts on on plastics and aluminium and pesticides in general?

Professor Robert Thomas: I mean, it's it's worrying. Yeah. I mean, you know, I hope it's not too late because there are a lot of microplastics out there. You know, it's you can apparently you can filter what's in your brain and produce a plastic spoon. I'm not sure if that's correct, but I read that recently. So we've already got, you know, our body's full of them. And the problem is they they they're carcinogenic in one river. The main way they're carcinogenic, they have hormonal effects. So they're xenoestrogens. Okay. And these xenoestrogens are probably responsible for men becoming having low fertility rates, the increased risk of younger breast cancers and testicular cancers. Um, so, you know, it's worrying the estrogenization of the planet, uh, you know, might have really dire consequences in the long long term.

Dr Rupy: So do you take the opinion that these are in some way responsible for reduced fertility rates and increased rates of testicular cancer and

Professor Robert Thomas: It's hard to put a, you know, it's hard to have a direct correlation, but of course, you know, microplastics have gone up recently and these things have also increased. There's other factors as well. Perhaps, you know, people are getting more overweight and generally not eating as well. But I I certainly believe there is. I mean, if you look at the breast cancer institutes, there was there was it was quite a long time ago now, about 15 years ago, there was someone from um from Reading who was pointing out that uh, you know, aluminium and parabens in deodorants from girls who'd been using it from a very young age was contributing to cancers. And I believe that data is true, particularly if you look at the quadrant where people were getting cancers where you tend to get absorption from these. So I certainly would not, I've got a 15-year-old daughter and I say, look, please limit the amount of uh deodorant, try to use paraben-free, aluminium-free. Of course, they're not as effective to reducing sweating. Sure, yeah. Uh, you know, try to limit them to days you need them. So it's the total quantity, try to reduce the total quantity and just use them, you know, for a special event.

Dr Rupy: Because I remember having some natural deodorant six, seven years ago and showing it to some of my friends and they just thought I was completely bonkers, you know, one of these conspiracy theorists, like, you don't need to worry about aluminium, you don't need to worry about these parabens and thallates and all this kind of stuff. And it's only now that the, you know, the sort of the message is coming out there, but there were early signals quite, quite, you know, a number of years ago, I would have thought.

Professor Robert Thomas: Yeah. No, I think I think it is a big risk. And that, you know, that's why we're trying to, you know, not buy so many plastic bags and reduce plastic in cooking and things. I think, you know, I think it's I just hope it's not too late.

Dr Rupy: Yeah, yeah, yeah. I mean, we've changed all of our pans to stainless steel and um we we tend to use glass tupperware as much as possible. So, um, in in terms of like the the prevalence of cancer, in in your opinion and perhaps having a read of the data, is it go to give the listeners and viewers an understanding, is it going up? Is the incidence of cancer, the prevalence of cancer, is this is this increasing?

Professor Robert Thomas: Um, well, the number of cancers is increasing, but we are getting older, of course, and and there's that factor. But the proportion of cancers is going up in younger people. Um, I mean, I up until this year, I was writing for National World News, which is a newspaper, and I was having to churn out three or four articles a week. So, uh, one of the things, um, we we were a recurring theme was, you know, for example, breast cancer in young women, bowel cancer instance in in young people. And it it there is a genuine increase. It's not just that you're screening the older people and they're getting cured and therefore we're not screening younger people. So in proportion, there's more young people. No, there's genuinely more, uh, there's an increase. And uh, and as an oncologist, I'm seeing, you know, a lot of young people. I mean, I I've got three people under 30 with with metastatic breast cancer at the moment and many under 35. And 20 years ago, that was unheard of. Um, so it is it's common to see young people with cancer now. Uh, you know, and there's there's lots of things, you know, it could be the gut health when you're growing up, it could be the exposure to the to the plastics because there's more around. Uh, it's a very sad fact that I read recently that the 60% of the calories for children are taken through ultra-processed foods. Um, you know, and they're just becoming more prevalent, cheaper, and the culture in young people is to to eat, you know, unhealthily. I mean, I suppose it's always been there, but it's just it's ubiquitous now. It's it's all around us. And those are the things which we need to change.

Dr Rupy: Do you think there's one core lever that is leading to the increase in the number of young people getting cancer, like obesity or processed foods or um poor gut health or exposure to some of these toxins? Or do you think it's the confluence of all these things all having their part to play on the acceleration and the likely the increased probability of of cancer?

Professor Robert Thomas: Yeah, I mean, we all call call it about multiple hits for cancer. You know, if your DNA can sustain some hits, but if you if you're hitting it from all different directions, it's much more likely those mutations will will go through and become a cancer cells. And, you know, I love Britain, I'm proud to live here, but you know, we're top of the we always seem to be top of the rankings. You know, we've got the highest childhood obesity. We had the lowest in Europe exercise levels in under 16 year olds. We have the highest intake of ultra processed foods. We seem to be, you know, unlike the Eurovision song contest, we come last, we seem to be coming first in all the unhealthy things.

Dr Rupy: Yeah, that's terrible. I mean, I I I get the Eurovision. I think that's more political. Yeah, yeah. But so with all these, you know, factors, I mean, the the big one that comes to mind is obesity, but I think we can't just explain the increase in cancers through obesity because there are uh lean individuals getting cancer. Um, it it seems to me in my mind that the ultra processed food, regardless of whether you're lean or obese, is having this pro-inflammatory, pro-cancerous effect on the body. Would would you share that opinion?

Professor Robert Thomas: I totally agree. I mean, obesity is is one risk factor, not in all cancers actually. I mean, there's some cancers it's slightly protective. Uh, but you know, that's more probably estrogenic type cancers a bit later. But I think it's the lack of exercise and the ultra processed food and the and the poor gut health. I mean, Great Ormond Street did uh a meta-analysis recently looking at what what could cause an increased risk of leukemia in young children. I mean, they've done pretty much nothing wrong. Um, and they found out that it was um clean kids. That was the only statistically valid factor that over cleaning, over clean children were actually a risk factor for leukemia, which, you know, we all get told, you know, buy a dog for your kids or people who are born by cesarean section because they didn't get exposed to feces when they were, you know, it seems to be true. The the data is is coming out. But on that, how that's relevant to you and I is it just shows that the microbiome and gut health is really important to protect us if it's good and increase the risk if it's bad. And that's why we want to do a lot of our research programs now are directed towards trying to do interventions to improve gut health and see tangible endpoints such as a progression of cancer or markers of inflammation so we can convince our colleagues to prioritize gut health uh to a greater degree.

Dr Rupy: Yeah. Um, I feel like we've done food in quite a nice way, you know, getting uh an anti-inflammatory diet, lots of polyphenols. We're going to touch a bit more on polyphenols in a second. Exercise, you'd mentioned it uh a little bit earlier that we have the lowest rates of exercise in Europe in under 16 year olds, which for me is mind-boggling because I've got, you know, harsh memories of having to do PE in like my underwear when I forgot my kit and stuff. So I don't believe that that the the under 16 year olds are not going to to their PE lessons because there was nothing in the way of mine. Um, what are the mechanisms behind exercise and and cancer prevention? Why is this such a a powerful anti-cancer tool?

Professor Robert Thomas: I agree. I don't know why kids are are doing less exercise. That's more of a sociology sort of question. Uh, but, you know, there there I mean, I I wrote a paper recently, um, you know, what are the biological anti-cancer mechanisms of exercise? And it was published in the British Journal of Sports Medicine. And, you know, it was a long paper because there are so many mechanisms. Uh, I mean, I can just, you know, list them off. There's the indirect and the direct. So the indirect would be it does help to reduce weight, even though some people say it doesn't, but you know, in in time it does. Uh, you know, you're outside, you get your circadian rhythm improved, especially if you exercise in the morning, which I always advocate. Um, you get some vitamin D exposure, so that's indirectly helping you. It improves mood because it gets your serotonin levels up, and mood can be a a driver for cancer as well. So there's the indirect mechanism. The direct mechanism is they improve gut motility, so they helps gut, um, it helps gut health. Um, and it actually changes the it's actually it creates a little bit of inflammation, but in a in a good way, it improves your immunity, so it enhances immune response. It actually produces these things called free radicals, which uh when you produce energy, they they start and then the body reacts by increasing your antioxidant enzymes. So exercise is an antioxidant. And then the list goes on and on. It helps with um various hormones which for example, it dampens down estrogen production um in people where it tends to be excess. So it reduces estrogen in your body without reducing weight. Uh, and then of course, it increases your muscle to fat ratio and that's also very beneficial.

Dr Rupy: And those muscles sucking up um IGF-1 as well. So IGF-1 is something that can be uh released with excess sugars and and dietary sources as well. Is that one of the mechanisms?

Professor Robert Thomas: Yeah, definitely. It it it, you know, if if people are struggling with pre-diabetes or want to promote the ketogenic effect, the best thing you can do is exercise on an empty stomach because it decreases your glycogen stores in your liver, it dampens down your your sugar levels or lowers your sugar levels, so your insulin levels then subsequently lower and insulin can actually drive cancer cells as well. So the mechanisms just go on and on and on.

Dr Rupy: If I were to exercise in the morning, but then sit like I am right now for eight hours during the day, am I lessening the effect of that exercise? Am I am I counterbalancing it in some way?

Professor Robert Thomas: Uh, yeah, I'm afraid it does in a way. There was a paper studied looking at um, well, look, if you do no exercise at all, that's that's the worst. Sure. Um, but if you if you are a weekend warrior, and I bet you are a bit of a weekend warrior, you do a park run on a Saturday morning or do something like that, uh, about then do nothing in the week, they were actually uh, they were they were still at a high risk. And this has been published this paper. Yeah. Uh, but if you are someone who manages to do a bit of exercise during the week and particularly avoid long periods of sitting, they were the ones who did the most. So, um, I sometimes give talks in the city and I said, look, you know, there really is evidence for stand up and sit down desk. There really is evidence for making sure people get up out of their desk and walk up and down the stairs every sort of hour or so. So you're right, it's a combination of avoiding sedentary behavior and then doing something where you really feel you've exercised. And that's another point. A lot of patients say, well, you know, I walk around the park a couple of times a day, which is good, but if you can throw in something where you actually get hot and sweaty and feel you've done some exercise, that's when you start seeing these changes happening in your bloodstream which have anti-cancer properties. And there's apparently 180 genetic uh signals which activate when you've when you've done that sort of exercise, most of which are are healthy.

Dr Rupy: Okay. So I should definitely be looking at some of those, you know, the treadmills that you put underneath your desk and you're walking. I don't know if you've seen those. I'm getting served loads of ads about them. Maybe I looked at it once. I've seen it, but I'm definitely going to look out for one. Yeah. Uh, great. Okay. And screening tools. So, there is one screening tool that I think uh has got a lot of news in the press recently around prostate cancer. Um, in the paper that we're going to talk about in a bit, I think you use the standard PSA test. What what are your thoughts on on prostate screening?

Professor Robert Thomas: I personally get a PSA because I want to be reassured. But if I um if my PSA is raised, uh I would be willing to accept no treatment as an option if I turn out to have a low-grade cancer. Okay. The problem is when you screen, uh the word cancer is so emotive that people might it will pick up a lot of early uh indolent or low-grade cancers, which actually is of real no benefit to that patient that it's been picked up. But because they've got the word cancer, then they demand surgery, they then after that become incontinent and have erectile dysfunction. So you're actually getting a large proportion of the population who had no symptoms and you're doing expensive treatments and rendering them symptomatic of no difference to their cure rate from that cancer. And that's the problem with prostate screening. That said, if you if people accept that they will go on to surveillance with a low-grade tumor and then you only treat the ones who need treating. I mean, ex-President Biden, for example, apparently's got an an aggressive cancer. So clearly picking up an aggressive cancer early is beneficial. And I have, you know, I specialize in prostate cancer. So on a weekly basis, there are some people who've gone along to the bowling club and had a PSA and they've come back and they have got what we call Gleason 8, more aggressive cancers, and they've done really well from screening and might well have saved their life. But on a health economic perspective, as over 80% on screening are going to be non-significant tumors, it's completely burdening the health system. So I think it's a question of education. We could say screen, but you can't, you have to then say you have to accept no treatment as an option if you've got an early cancer, which frightens many people.

Dr Rupy: Yeah, yeah, because I think the impetus would be to treat something. There's something there, get rid of it, cut it out, treat me with something. Um, I think that's quite stress-inducing for a lot of people. Um, so you can understand sort of this idea that you're just there like a sitting duck and it can be quite, you know, hard to explain the watch and weight um uh approach uh to to low-grade cancers.

Professor Robert Thomas: And the way the government has got around that is they've just told all the doctors not to screen. That's why the official statement is not to screen for prostate cancer. And I've sometimes been called by, you know, regional officers and saying, you're not promoting screening, are you? Um, I think it's more of an educational thing. But and it and it's sad. You see, for example, we're just writing up our paper at the moment and we're looking at the sort of back down data. Even though 60% of men initially accept uh active surveillance if they've got low risk cancers, only 10% at five years are still on active surveillance. So most of them over, you know, the five years since diagnosis, just as you've said, they're sitting at, you know, they're sitting in the middle of, you know, when they're over a cup of tea thinking, you know, I've got cancer, nothing's being done or they're waking up in the early hours of the morning and they sort of uh they're ending up getting a treatment. And it could be triggered by the PSA going up, for example. Um, or maybe the MRI scan showing, oh, it's a little bit worse. So it it then creates this even further anxiety. Sure, yeah. Um, so what we're doing now, we're doing trials to um give patients or empowering patients to help themselves to reassure them that they don't need to go on to treatment. And the best way to reassure them is making sure their PSA doesn't go up and making sure the cancer doesn't get worse on uh on the MRI scan or, you know, sometimes improving symptoms. Um, and that's not been looked at to a great deal, but I think it should be because that would save, you know, thousands and thousands of men from unnecessary treatments, which is happening. Of course, coming back to your original question, yes, if we had a screening tool which only picked up the aggressive cancers, that would be perfect. And I think there's, you know, there's school, there's a new saliva test, there's new urine tests, which maybe be able to look at the sort of DNA of the cancer cells and say, yeah, that is actually something you need treatment for. So, um, if they can do that, that would be fantastic.

Dr Rupy: Yeah. You you mentioned um stress and mood earlier. Um, as a potential factor in um cancer development. Is is that is that been explored at all? Do do we know stress is is a potentially is potentially an independent risk factor?

Professor Robert Thomas: Um, yeah, I mean, um, again, as a chapter on my book looking at stress and how it integrates with with cancer. Um, most of the data is actually looking at people with established cancers to see if people who are stressed are more likely to have a relapse. Okay. And there are quite a lot of data for that. There's a there's a very good study from San Francisco and it looked at about three and a half thousand men with prostate cancer and then um did questionnaires looking at stress levels, which we don't often do actually. Um, and it found that the men who had the highest stress levels actually had a higher risk of prostate cancer relapse and higher death from prostate cancer. So there was, you know, so there's no doubt that the data is there. The underlying mechanism is more difficult to explain. Maybe people who are more stressed are more likely not to eat healthily, more likely maybe not to exercise. Uh, there could be other mechanisms that stress can be linked to poor gut health or and vice versa. Yeah. Um, so there's definitely a correlation of why that why the mechanisms are more difficult to explain.

Dr Rupy: Yeah, and it brings you back to the earlier points we were talking about with regards to um younger patients getting cancer because everyone, I think is a lot more aware of the mental health crisis. You know, there is a a high rate of anxiety amongst younger people. Um, I personally went on a silent retreat recently and I realized just how addicted I am to my phone. And I'm so glad that I'm not in school where smartphones were readily available and used all the time. And I think that distance between my phone is personally really, really beneficial for my mental well-being. But a lot of young people and those in work, obviously depend on their phone for a lot of things. So, you know, that's sort of like my bias. I think phones are are responsible for a lot of stress in in our environment. And I wonder if this is also having an impact on on cancer rates.

Professor Robert Thomas: I would I would agree. I would agree. I mean, multiple, I mean, they say that social media is increasing stress generally in kids and things. So, yeah, I mean, I I'm, yeah, I think we need to do more work exploring the exact mechanism. Um, you know, it could be just that it's it's causing your gut to just um, you know, have too much motility and reducing gut health. It could be something as simple as that. It probably probably isn't that simple, probably more mechanisms, but yeah.

Dr Rupy: Yeah, yeah. Um, you did a really interesting study that I want to dive into. Um, I mean, a number of years ago, you did the Pom-T study. Um, but there's something recent that you've done that sort of it's sort of like a a combination of all the different things that you've done within your career looking at probiotics and polyphenols and phytochemicals. Um, can you explain what this study uh was looking at?

Professor Robert Thomas: Um, thanks, Rupy. Uh, yes, you're right. I mean, I I'm a little bit selfish in my research because I really want to find out things which I can do for myself. And as a consequence, hopefully my patients and friends and family and things. So, you know, there's a lot of data on, you know, gut health is bad for you. There's lots of um retrospective studies correlating poor gut health with uh higher risk of diseases. But there's not a lot of data in humans on whether you can do an intervention to improve gut health and um reduce the risk of say cancer progression. Um, there wasn't a lot of evidence that it reduced the risk of developing long COVID until we did a trial three years ago. Um, so this current trial, we looked at um we as you mentioned the Pom-T study from 14 years ago, which was a a capsule which contained four phytochemical rich foods. And we did show it had a a small effect on PSA progression. And that hopefully that guided men to say you can increase your phytochemicals in your diet and have some impact. Um, that's quite old now and there are ways with new food technology to enhance capsules to make them more potent, to get rid of some of the impurities. And there are new ingredients which have been shown to help prostate cancers like cranberry and ginger and things, all most of which are geared for reducing inflammation. Um, so we wanted to sort of combine the latest technology in in phytochemicals, but the main question we wanted to ask is, could we do an intervention to improve gut health such as a a good quality probiotic for the trial against placebo? Could an intervention improving gut health reduce the risk of cancer progression? And that was the hypothesis for the study.

Dr Rupy: Okay. And so looking at this study, so we had 200 men, early stage prostate cancer, some of them were given the phytochemical rich supplement that we'll go into some of the ingredients in a second. And the other arm were given the same supplement but with with a probiotics. Is that right?

Professor Robert Thomas: Uh, yeah. I mean it was a we this trial, we very much worked with patients with prostate cancer because there's no point us sitting around with our dicky bows on and say this is what we should be doing. And then we ask patients, they say, no, thank you. We need to work with patients. We we were the fastest recruiting trial in the UK for the six months it was on because all the patients just said, yep, I like that. I'm going to go into it. And we're not claiming credit for that. It was actually because the patients helped us design it. It was attractive to patients. So we said, look, you know, we know that 60% of them take lots of different supplements, some of which could help, some definitely don't help. But the problem is if you use that very uh diverse baseline, there's too many variables for it to reach statistical significance. So we need we need to have a level playing field. So we said, look, we will give you what we think is the best phytochemical rich supplement right now. And by the way, we have to use supplements in trials because uh they're objective, but of course, we'll come on to that could we achieve this with diet later. But for the sake of a trial, we have to use a supplement because it's an objective way to increase the intake of measurable phytochemicals. So we said, look, we will give you what we think is the best currently available. Will you then stop everything else? The answer was yes. So good. So we got everyone on the same baseline.

Dr Rupy: So they stopped all their vitamins and minerals that they were taking because you were going to give them a phytochemical rich supplement and they weren't willing to do that. So they weren't willing to to be part of an arm of the trial that didn't have anything at all.

Professor Robert Thomas: Correct. Gotcha. Yeah. Or or just a placebo, for example. Gotcha. So they were all happy. They got a free baseline, which they all took. And we then we measured the rate of progression of their cancer before and after the intake of that, which actually was successful. It did reduce slow the rate of cancer to a um, you know, a statistically significant but small degree. Then on top of that, we randomized what we were really wanted to find out, the probiotics or not. And it was double blind, so the patients didn't know they were actually on a probiotic or not, and nor did the doctors or the statisticians when they analyzed it. And then they they stayed on that. We measured uh the MRI progression on uh of their cancer on MRI. We measured um markers of inflammation, we measured grip strength, uh and then we measured uh PSA progression. And the patients who were on the phytochemical rich supplement alone had a reduction of about 20% in their progression rates, which I forgot to mention, everyone in the trial actually were progressing at trial entry. So they were slightly a worse group than your standard active surveillance because they were progressing and they were sort of thinking of coming off it. That's why they were referred to us really. And uh so so there was a 20% reduction, which is highly significant. Yeah. If they took both, there was a 43% reduction in PSA progression, which actually dipped below normal. So most people actually their PSA went down. Wow. Uh, which was very much welcomed by men in the study. And on top of that, uh we were very surprised to see that in the in the patients who were on both, there was actually about 10% had actually the disease shrunk on MRI scan and there was there was just a few patients where it progressed compared to the other group where there was quite a few who still progressed. Uh so it wasn't just a um, you know, a marker on a blood test. It wasn't just a number of PSA. It was reduced progression on MRI. It was also reduced markers of inflammation and there was actually strength had slightly improved in the combined group as well. So in other words, their overall wellbeing improved as well as markers of cancer.

Dr Rupy: Which is pretty remarkable and it sounds like it would have been quite shocking for you to see that there was regression in some of these patients. I mean, did you do a deep dive into those patients? Be like, what what is it about them that led to regression? Because that is that's sort of unheard of.

Professor Robert Thomas: Absolutely. Um, we were we were expecting that the PSA would slow because we've previously um shown that 14 years ago, albeit with a sort of inferior to today's standards uh supplement. And we were very pleased that the level of uh reduction was was greater than we'd achieved 14 years ago. I'm, you know, like yourself, I'm 100% convinced that gut health has been underestimated as a risk factor for cancer and cancer progression. So I was not surprised by the results that the probiotic significantly reduced rates. And you could sort of see, you know, patients said they felt better, they had less, you know, they had less fatigue, they were more alert. You could just feel that people were looking better. Um, and, you know, but that said, we presented the data in ASCO, which is the world's biggest cancer conference in San Francisco. And, you know, there was genuine surprise um from the audience. Um, but nice surprise. I mean, it went down very well. And, you know, they've all got the core data. It's been, you know, triply analyzed because it's being submitted to some very uh good journals who will, you know, want to look down and make sure all the trial has been conducted properly and independently audited. So, you know, it's it's everyone's happy with the data. It's not just a fluke. Um, but what I was surprised about, as you say, um, because it's fairly subjective on the MRI when you look at a prostate cancer, but to say that there were um, there was no, there was only regression seen in the patients who were on the combined group. And you very rarely see regression. So it was only about 10%. And the number of people who progressed was about three times higher in the single group compared to the combined group. And that was also statistically significant. So then we looked at those and said, look, you know, what's what there must be something else with these. So we have been, as you said, deep diving into that. First of all, we wanted to check that, you know, did that correlate with PSA? So the, this we're getting quite technical now. So the patients where they showed um a regression, there was a massive reduction in PSA. So it was a real, it was definitely a thing. And people who showed progression in both group, the PSA still had gone up quite a lot. And what that tells us and colleagues that the PSA is actually a reliable marker. It does correlate with underlying disease. And these ingredients aren't masking the PSA. Sure. Which has been a criticism of trials. And I still get this daily from colleagues saying, oh, you might just be reducing the PSA, so you're not really affecting the disease. That said, we did a a meta-analysis of foods which could reduce um PSA. And how many trials did you think we found? Zero. Zero. Okay. So it's one of those myths which people talk about. And I said, there must be one trial out there. No, not a single trial. Nevertheless, you have to respect their opinion. And therefore, we could say, we've absolutely proved that, you know, phytochemical rich foods and strategies to reduce gut health reduces PSA significantly. And that correlates with underlying disease and markers of inflammation.

Dr Rupy: Okay, there's two questions that I know the listeners are going to have. What were the ingredients in the phytochemical rich supplement? And do you think we can mimic this effect if you don't have the supplement with food and and other elements of the diet?

Professor Robert Thomas: I mean, that is the key question. Um, because as I've just said, in a trial, you have to use supplements because you can't reliably change diets objectively enough to see differences in people because people won't be compliant to that degree. Um, and, you know, supplements are a good way. If they're a well-made supplement, they are a good way to boost your intake of these things. People in the British diet, for example, don't have much fermented food. And I spend my life telling people to eat more kimchi and and things. But, you know, we don't in the British diet, you know, other than sort of the the converted like you and I. Um, so they are, they're a practical tool. I call it low-lying fruit. You know, you take two supplements in the morning with your breakfast, you're actually massively increasing those elements of foods which have anti-cancer properties. But, you know, they're not really the answer on a population basis. You know, we really need to make sure people's diet as a whole changes. Now, there are, there was in San Francisco in the conference, there was next to me was um, a similar because obviously put all the dietary talks in one room. Right. Uh, there was a a guy looking at omega-3 foods and and prostate cancer and he found a correlation between um increasing omega-3 and reducing progression as well. So it's not just about what I'm talking about. Um, and he quoted two trials where people had got patients with prostate cancer and advised them to eat healthier and there was no effect. Unfortunately. Um, so the only two trials we've got where they did somehow try to randomize a group where they ate healthier and not, although how they, you know, measured that is difficult to say, but they did and they showed no benefit. Okay. That's not to say that you shouldn't be eating healthily. I think when you look where you deep dive into those studies, I don't think they did enough. I think if you're going to change your diet for an anti-cancer perspective, you really have to do quite a lot from your average USA and British diet. Absolutely. As we said before, you know, we eat a lot of processed foods and blah, blah, blah. You really have to make an effort. And I I suspect if you were to do those trials again, but, you know, force them to eat your food every day. Not that that would be bad, of course, it'd be fantastic. But you know what I mean, if you you really have to work at it. You have to wake up in the morning, you have to go for a walk before breakfast, get your vitamin D and circadian rhythm right. You have to start with no sugar at all. You have to, you know, have slow release carbs in your your lunch would be full of herbs, spices, chemicals. You really have to do that level to replicate what you can get in a supplement. But I think you can. 100%, I think you can.

Dr Rupy: I agree with your point about doing enough to educate people on what a healthy diet is, because your average person who isn't listening to the Doctor's Kitchen podcast as an example, you know, will probably go to the supermarket and just choose the healthier looking cereal or choose a healthy snack bar or, you know, choose the the healthy looking sandwich or go from white bread to brown bread. And we know, you know, it's it's swapping one ultra processed food for another and there's not going to be a significant difference in terms of fiber intake or the impact on your gut health or polyphenol increase either. So, um, I think there's probably that. And I think you've shown eloquently in this study when you do increase polyphenol, uh, phytochemicals in the diet, um, because I went through the uh ingredients list and it's cranberry, green tea, pomegranate, turmeric, broccoli, ginger, um, all of which were contributing around 1,000 milligrams of phytochemicals across those varied foods on top of whatever they're consuming. So you you're showing, you know, this is to your point why we have to do supplement studies, you're showing the objective increase. I believe it would be uh powerful enough to mimic with diet, but I mean that would take a lot to get those ingredients alone into your diet every single day. It would requires a in some cases a complete overhaul of their habitual diet.

Professor Robert Thomas: Yeah, I I agree. I think it is achievable. Yeah, sure. But it's not for many people. They don't want to do it. They don't maybe like those foods, uh, not, you know, they they they they have excuses, you know, they say it's expensive. I don't think eating healthily is expensive at all. I think it probably might even be cheaper. Um, but uh, you know, supplements are attractive to them because as I say, it's low-lying fruit, they can just add it. But um, on their own, you know, you know, and you still got a terrible diet, they're probably going to do nothing either on the other end of the spectrum. You need to do both, don't you?

Dr Rupy: I'm going to bring this chat to a close, but I want to ask a couple more questions. Um, what do you wish more people heard in clinic earlier on their journey if they've if they have been diagnosed with cancer?

Professor Robert Thomas: It's a difficult question. I mean, every every person's an individual. So, you know, it depends what um, what they want to hear, what what's going to help them. I mean, look, if you're really morbidly obese and you start saying you need to lose weight, you're actually completely wasting your time and actually probably upsetting them. Um, I would say if you are going for biologicals, I think there should be a more integrative approach to improving gut health as well as exercise. Um, encouraging them to know that they can help themselves, I think is very positive. That said, we don't we want to avoid a blame culture. So, you know, you've got this cancer because you've you've been doing all the wrong things. Your cancer's come back because, you know, you didn't, you know, you didn't make the effort. And and that that guilt is actually counterproductive. It actually increases stress and and and so forth. So I can't really answer that question in a single one or two words. I think it's looking at an individual. I would love it that patients have have more opportunity to speak to, you know, integrative oncologists or, you know, nutritionists or exercise clinicians. You know, the perfect oncology clinic would, you know, would have a chef, a a a nutritionist, an exercise psychologist, or sorry, an exercise clinician and and a psychologist. But I mean, you know, that's perhaps a long way off.

Dr Rupy: Yeah, yeah. I think we can achieve that at some point. I I definitely think with the advent of virtual appointments and AI, I think it's achievable. I think we're going to see a rapid progression of some of these services being made more available just because of the technology enabling that. Um, and the last thing I want to ask you about is what are some of the things that you do personally to ensure that not only you're preventing cancer, but also looking after your your general health and well-being? Are there two or three things that you do every day to help with that?

Professor Robert Thomas: I try to start each day without any processed sugar at all. And I found that's probably the number one thing which has helped me over the last few years because you can have, you know, a breakfast with some nuts, uh pumpkin seeds, pine kernels, um fruit, plenty of fruit. Um and then you just don't get hungry till till till 2 o'clock because you haven't got this dip and fall in your sugar levels. I try to keep exercise. I have to confess, I do eat, try to eat um salad and and something colorful with each meal, herbs and spices. I do take um two of the supplements we used in the trial. Really, yeah. Because I just think, look, I know what's in them. They're now commercially made, by the way, if they what's the brand? They're called Your Fyto and Your Gut Plus. Your Fyto. Okay. Um, you know, they they provided them free for the study. Um, and, you know, I just it just gives me reassurance that that that I'm just boosting my phytochemicals and and gut health. Um, so I do I do take those supplements. Um, you know, try to avoid snacking between meals to allow your gut to to empty. Um, but, you know, I still enjoy a few glasses of wine at the weekend, you know, and probably get too much sun from being outside, but, you know, life's about a compromise. Yeah. And enjoy it.

Dr Rupy: Yeah, absolutely. Um, the phytochemical supplements, I was going to ask this actually whilst we were talking about prostate cancer, that that trial was obviously looking at men. Do you think there would be benefits across different types of cancer, particularly in in women's uh cancers as well?

Professor Robert Thomas: Um, yes. So when we made um Your Fyto, as it's now called, or when I say we, there was a committee, one thing we didn't want to do is make sure there was phytoestrogenic properties with any of the ingredients because they are a bit more controversial. Phytoestrogenic foods are very healthy. When you start putting them into a supplement, it could be a bit too estrogenic. Sure. Um, so yes, and and there was a study in Japan which looked at those ingredients of um women with cancer who cancer survivors who had many menopausal problems and they saw a benefit for mood, joint pains, um and other things like hay fever and stuff. But, you know, so we know those food help help multiple things. So I do actually say to women, you know, maybe if you're looking for a supplement, that would be something to try. And a lot of them come back and say their joints feel better, as you would imagine with food which contain, you know, ginger and turmeric and stuff like that. Yeah. And in the in the trial, I forgot to mention, uh there was actually a 25% improvement in urinary symptoms, um such as getting up at night to pass water, as well as a slight increase in erectile function. Um, what it also showed is that the um testosterone levels marginally increased. So despite an increase in testosterone, you're reducing the prostate cancer, which is really quite, that's they call that the testosterone sort of uh dichotomy. Um, now, so in other words, men who are looking maybe to increase their fertility or people with arthritis, I say, well, these are the type of things you should be looking at as well as the diet, of course. So yes, for different diseases, I do think there is a role. And also for the probiotic because it's um, you know, well-made and it's been used in a clinical study, so the quality assurance had to be quite high. It also contains some vitamin D. And I don't know if you know, but vitamin D and probiotics are are are synergistic, they help each other. Um, and there's many situations such as if you're traveling, if you've had some recent antibiotics, uh if you've been into hospital where probably boosting your probiotics would be useful. Yeah. Um, in the longer term, if you have good gut health, you don't need a probiotic, but there are, you know, for short-term things or if you're going through the winter and needing your vitamin D levels to be high, I think there is a role.

Dr Rupy: Brilliant. Professor, I don't know how you do this. Uh, you've got a full-time gig in Cambridge and you've got the uh uh the integrative position now and you do books and talks and all the rest of it. It's phenomenal. So, I appreciate you. Thanks so much for for coming on and sharing some of your wisdom. It's brilliant.

Professor Robert Thomas: Thank you, Rupy. It's always a pleasure.

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