Professor Robert Thomas: We all talk about the the gut brain pathway, but there is actually a gut lung pathway, which is just as well established, but not as well talked about. And we know if you have poor gut health, you actually get abnormal inflammatory bacteria leaking into the into the bloodstream and getting to the lungs as well.
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 where we discuss the multiple determinants of what allows you to lead your best life.
Professor Robert is back on the podcast talking about all things to do with long COVID and some preliminary results from the UK's only COVID nutrition intervention trial, the Phyto-V study. A randomised, double-blind, placebo-controlled trial evaluating the influence of a phytochemical-rich whole food capsule plus a probiotic capsule on clinical outcomes among individuals with COVID-19 viral infection. The hypothesis for this study is that starting a nutritional intervention in COVID-19 positive patients displaying symptoms could shorten the severity or duration of illness. This may or may not have an impact on long COVID, and there are some anecdotes of benefit. However, we can't say for certain whether it's useful for everyone. I know what the next question is going to be. What polyphenols were included in the supplement, I hear you ask. Well, the researchers used ones that show promise in other viral illnesses and are found in common foods, including the flavanone polyphenol hesperetin found in citrus, the anthraquinone derivative aloe-emodin found in aloe vera, quercetin, a common flavonoid found in onions, apple, pomegranate, and citrus, apigenin, a polyphenol found in parsley, camomile tea, and fruit, curcumin, obviously found in turmeric, and a whole bunch of others. As a reminder, Professor Robert Thomas is a consultant oncologist at Bedford and Addenbrooke's Hospitals, a clinical teacher at Cambridge University, and visiting professor of sports and nutritional science at the University of Bedfordshire. He is lead of a lifestyle and cancer research unit and is medical adviser to the website cancernet.co.uk. Through his amazing work, Professor Thomas has previously been awarded the British Oncology Association's oncologist of the year and the Royal College of Radiologists medal. On today's podcast, you will learn about the details of the study that is yet to be published, the theory behind using a probiotic as well as a nutrient-dense supplement, the tips for COVID that are evidence-based which actually could reduce severity, the new study looking at how to potentially enhance the antibody response of the immune system for the vaccine. Now, rather than to try and demonstrate the need for a supplement specifically, what Professor hopes to show is that using a polyphenol-rich diet may be beneficial to prevent prolonged COVID symptoms. The details for the trial and other trials that Prof is is mentioning here on the are on the doctorskitchen.com. So, you know, do check out the podcast show notes. We're doing another podcast with Prof dedicated completely to his new book, How to Live, which I cannot recommend highly enough. It is fantastic, and I think it needs its own distinct episode to to dive into. So, for now, please enjoy this conversation with Prof Robert Thomas, but we will be chatting to him again soon.
It's so much easier when I can cook for you and you're here, you know? And I set up all the mics here and everything. I bet you're missing that this time.
Professor Robert Thomas: It's, yes, and it's it's more enjoyable for me to to eat the food as well, obviously.
Dr Rupy: Have you cooked anything yet? I I remember giving you my book.
Professor Robert Thomas: Well, I I yes, uh, yeah, my wife's cooked a few meals and I've I've done one and I've bought an oven. So you've it's uh things are changing.
Dr Rupy: Brilliant, brilliant. Well, it's nice to know you've got an oven. That's uh that's progress. How have you been?
Professor Robert Thomas: Uh, yeah, very well. We're we're busy in the hospital because we've opened up a lot of the uh all the oncology patients which we've been put on hold with hormones and things delaying the treatment has all suddenly opened up all at the same time. So in in typical NHS fashion, suddenly you've gone from having two or three patients in a say a radiotherapy clinic to having 25, you know. So we're we're we're we're rushing to get through the numbers, which is good. Um it means we're we're getting through the backlog. Um but at the same time, COVID's not quite over, so we're dealing with those issues as well. So uh and on the research side, there's still lots going on, as we'll no doubt talk about. Um so yeah, it's all happening.
Dr Rupy: Yeah. Well, let's kick off with that because obviously I want to get to um the amazing piece of work that you you've done, um your piece of literary work. But to start off, I think maybe we should talk about that that nutritional intervention trial that I was uh fortunate to be to be a contributor to.
Professor Robert Thomas: Thank you.
Dr Rupy: So describe the trial to to me.
Professor Robert Thomas: Okay. So, um, as you know, we we do a lot of lifestyle and exercise related studies, um, to do with cancer and other chronic diseases which are more common after cancer. Um, but we've been, you know, put on hold a bit. We had to cancel the start of a gap four study looking at exercise in prostate cancer. So we thought we'd use our resources to see if we can help with the fight against COVID. And it's very obvious from, you know, writing my book and looking at the literature already published and what we've learned over the last year, that although you can't blame anyone for catching COVID, you know, it's it's uh, you know, it's affecting all types of people. There is clearly a correlation that if you have uh different comorbidities, uh you're more likely to suffer from it. Um, so for example, in the New York, uh last New York published data of the 23,000 people who unfortunately died of the disease, it was only 0.9%, so 98 who didn't have a comorbidity. So clearly comorbidities are very important in the severity of this disease, as well as age. But, you know, actually there are some data you can be in your 80s without comorbidities, which is which is unusual, mind you, uh where there's only about a 2% chance of mortality. So, um so we were wondering in in our trial whether you could change people's diets and lifestyle quick enough to have an influence on this pandemic and even have an influence on whether they've caught it already. So that's the the basic hypothesis. So we randomised people to if they've had symptoms of COVID and a positive test, uh we randomised them to um it was basically a food capsule which contained sort of healthy polyphenol-rich foods like um like aloe vera, pomegranate, turmeric, that sort of thing. And we gave both groups a probiotic supplement called Your Gut Plus was provided to us by the manufacturers. And we were looking to see over the duration of symptoms and whether they get readmitted to hospital and whether they pass the disease onto family members.
Dr Rupy: And so what was the name of this trial?
Professor Robert Thomas: It was well, we there's a long name and there's a nickname as trials go. We we've nicknamed it the Phyto-V study, which is basically, you know, because of the phytochemicals we're hoping to enhance in the diet and the V stands for virus.
Dr Rupy: Okay. So to summarise, you had patients who had symptoms and a positive um PCR test, I'm assuming, um proving COVID. And this was um after they've had this and and you gave you randomised them to to either the intervention, which was the high nutrient dense supplement plus probiotic or the placebo plus the probiotic.
Professor Robert Thomas: Yeah, that's correct. We we actually started off with the probiotic um randomised as well. Um but we recruited very slowly um in the first six weeks because nobody actually wanted an arm with potentially two placebos. And actually, once they started reading it, they saw that the the probiotics were probably a a beneficial element, even though it's not been proven. So we had to change it. We had to do a trial submission and change it where we gave probiotics to both arms and just randomised the the other food capsule. And the patients were much more satisfied to go into something uh with their perception that they that it was beneficial, whatever arm they ended up in.
Dr Rupy: Yeah, that's always a tricky thing with trials, isn't it? You have to sort of convince them to want to go in the trial and when they do a bit of reading, they're like, hang on a minute, I kind of want that.
Professor Robert Thomas: Yeah, yeah. So, you know, and and and it's it can be frustrating because, you know, when you publish it, people will be saying, well, why didn't you randomise the both? But, you know, we are in a real world and we have to recruit patients and we have to recruit patients quite quickly. So you have to compromise a little bit, but I still think the design is is good.
Dr Rupy: And and before we talk about some of the preliminary results and and what the stage of it is at the moment, what what was the thinking going in behind the um the Phyto-V element, so the the high phytonutrient dense um supplement that was given in addition to the probiotic in the treatment arm?
Professor Robert Thomas: Uh well, in our unit, we've done quite a few studies using um supplements because in a in a scientific perspective, it's quite easy to quantify the the food intake. I mean, we're not saying that supplements should replace a good diet like what you produce in your books, uh but on a scientific perspective, it's easier. And we did one called Pommy T, which was for uh prostate cancer, and that was quite successful. So we were we've got quite a lot of experience in that. And we know that they are a good way to increase what we call polyphenols in the diet. And these are the chemicals which give food the colour, smell, and taste. And we know that these polyphenols have enormous health benefits. They help with gut health by acting as prebiotics. Uh they have direct anti-inflammatory properties. They also enhance the anti-oxidant pathways, but not by acting as direct antioxidants, um which which aren't good, like, you know, vitamin A and vitamin E supplements. They just enhance the process. So they they help uh an individual create an inflammatory response when needed and then um downgrading it when it's not needed. Um and in COVID, you know, a lot if you look at the the problems why people get this horrible cytokine storm is because they get this inappropriate excess and not very well-functioning inflammation on on the same side, they're using up their oxidative pathways. And that's thought to be the mechanism of um the you know, the the horrible lung disease, which is ultimately fatal. So that's what we're trying to stop in the acute phase. Um and in the in the chronic phase, we know, well, we we suspect the hypothesis is um that you again, you have this long-standing excess inflammation combined with poor gut health. So we're hoping to sort of correct that.
Dr Rupy: Yeah, and this this long COVID phase is something that I think warrants a lot more attention because by some conservative estimates, there're going to be around half a million people who have a post-viral syndrome that we've discussed in the podcast is this prolonged feature which is characterized in a lot of cases by fatigue, um lack of lack of energy, brain fog, um 50 plus symptoms that have been identified in a recent paper. Um but but of which people have a spectrum. Some people might have that for four to six weeks. Other people are still suffering with it even now, a year on.
Professor Robert Thomas: Yeah, you're right. I mean, uh when we started the study, we thought we'd get people, you know, within four weeks of an acute infection, but people were coming forward uh up to three or four months later saying, you know, their joints are aching. And as you say, uh the end points, it's difficult to sort of, I'm not sure if we'll reach statistical significance because there's so many different end points in the long COVID. Some people say they're getting tinnitus, other people joint pains, other people rashes, still got bad taste. Um I think we'll find a way of grouping it together and we're working with the statisticians now. But but you're right, it it's it affects lots of people individually. The number one symptom which seems to affect everybody is fatigue. And um we've got a very sensitive measure of fatigue, as you know, because you were in the study. Thank you very much. Um and uh you know, I think that whenever there's something wrong with humans, we all tend to feel a bit tired. I think it's like a universal symptom of any disease as far as I I'm aware. Um so hopefully we'll get an end point from that. Um but you know, there is there there is my belief or my hypothesis is that gut health is a very common denominator for all these because as you know, um if you have poor gut, you get a bit of a leaky gut, you get gaps opening up. So you get toxins going into your bloodstream, you create this chronic um you get this chronic excess inflammation, uh and then that triggers sort of uh attack on your organs, your brain, and your lung. Um and I mean, I recently gave a talk looking at the we all we all talk about the the gut brain pathway, but there is actually a gut lung pathway, which is just as well established, but not as well talked about. And we know if you have poor gut health, you actually get abnormal inflammatory bacteria leaking into the into the bloodstream and getting to the lungs as well. And when you when you take swabs of people's lungs, you find an abnormal microbiome of bacteria as well as the pathogenic viruses. Uh and you know, that can keep the symptoms going. Uh but you know, it remains to be seen. We're we're we're seeing some excellent early results, uh but it remains to be seen whether intervening in measures to improve gut health would shorten long COVID.
Dr Rupy: Yeah. I mean, I know we can't say for certain right now as the the the intervention trial isn't over, but what sort of responses have you had from people um that you're aware of that might be on the on the intervention arm of the trial?
Professor Robert Thomas: Yeah, well, I can talk about the open phase of the study because as I said, the the the Your Gut Plus was was selected uh mainly to have lactobacillus um on the grounds it was one of the safest uh probiotics. Uh you you're very unlikely to get excess bacterial overgrowth with a lactobacillus. So it's the same sort of bacteria you get in um kefir and milk and yoghurts and things. Um but there's five different strains. Um and but the important thing is it's mixed with a with a prebiotic inulin, which which supports them. So that's open. Um and you know, we've had emails from, you know, across the country saying, you know, wow, I you know, my cough hasn't got better or this hasn't got better, but you know, my my bowels feel so much better. I feel more comfortable. My fatigue's improved. So, you know, it remains to be seen statistically, uh but I would be very surprised if not because um virtually everyone in the study has said, uh who started off with symptoms. You didn't start off with many symptoms, so you can't get you even better. Uh but most people and and as I said before this podcast started, um a lot of people who've entered the study have a long history of um, you know, being on anti-indigestion medication, to have repeat endoscopies, um history of uh, you know, oesophageal reflux, intermittent constipation and and and diarrhoea. So all signs of long-term poorer gut health. And it's that group seems to to me so far to have the best benefit, which makes sense really, isn't it? If you're if you're starting on a lower standpoint, you're more likely to improve.
Dr Rupy: Yeah, absolutely. It's especially with a working hypothesis that it is to do with poor gut health. If you're giving an intervention that could potentially alleviate that, then it would stand to reason why you're seeing such uh incredible potential benefits.
Professor Robert Thomas: Yeah. And it's well, it's not just about that. The other I mean, if you go onto the trial website, so it's phytov.com, you will see the the the hypothesis for the trial. These these polyphenol-rich foods actually in the last SARS and previous flu outbreaks, they have actually been shown to have very significant direct antiviral properties, which may not be such a factor in the long COVID because hopefully the viral virus is is sort of gone. It's just the consequence of it. Um but they show very clearly in a number of different viruses to reduce viral replication, to reduce viral penetration into cells, and viral shredding. Uh and that's been well reported. There's hundreds of papers showing that. Uh but again, nothing yet in in COVID. So that was the other reason for including those.
Dr Rupy: Yeah, you know what, it's really interesting. So I had a conversation with Professor Altman about the potential mechanisms by which long COVID works. And one of the hypotheses is a is a a dormant um viral infection that sort of hangs around and there's a similar way to EBV. So if those phytonutrient uh supplements are actually reducing viral replication, again, it stands to reason as to why that might also be having an effect as well.
Professor Robert Thomas: Yeah, I mean, that that's true. I mean, we we were more thinking of the effect on the body in that in that group. Um but yeah, that that would be that would be interesting as well to we're not actually measuring the amount of viruses, so so it would be hard to to prove that. Um but yeah, that would that would be a factor. And and uh you know, from my knowledge of of resistance, um and these new strains is is it's probably coming from cases of long COVID where where the virus is just hanging around and it's not quite being killed and then it sort of mutates and then spreads out from there. So the sooner we knock long COVID on the head, the the less likely these resistant strains aren't going to emerge in my view.
Dr Rupy: Yeah. I know we have to be very careful about making blanket recommendations for people with long COVID, but if there were some elements of the trial in its current standpoint that you think would be beneficial for people to know about, um it sounds to me like, you know, looking after your gut, using a high polyphenol-rich diet and um uh maybe even some probiotics as well. Um what other elements of the nutrient supplement do you think would might be beneficial?
Professor Robert Thomas: Um yeah, I mean, as as you say, you've got to be careful not to tell people not to get vaccinated and not to socially isolate because those are, you know, the that's, you know, that's said and and we're not blaming anyone. But I did do an evidence review um on the keep-healthy website, which is um, you know, what what have we learned so far in the last year? And none of it is is controversial and most people would say it's it's common sense. But I tried to link it to references. Well, it is all linked to references. And there's there's about 10 things we can we can concentrate on on a daily basis. So, you know, number one would be to try to reduce a bit of weight if you're overweight. We know that obesity is is linked to a high higher risk of COVID. Um of course, it's not easy to do that quickly, but, you know, um number one. Uh the concentrating on factors which improve gut health, so reducing processed sugar, eating live foods like kimchi, kefir, um sauerkraut, etc. Eating, you know, polyphenol-rich foods such as uh anything in your book, basically, you know, herbs, spices, beans, nuts, etc. Exercise, we know that exercise is linked to um improved gut health. And there's various theories behind that. Um vitamin D, I think is pretty well accepted now that if you have low vitamin D, you have a higher risk of COVID and a more serious disease. There's not a lot of evidence that taking excess vitamin D will will improve you, but there was a study published uh last week in fact from Cambridge looking at the um the amount of vitamin D deficiency we have in the UK and it's about 56%. So it's a fair bet that in the winter you should be taking some vitamin D supplements. Um avoiding excess vitamin A and vitamin E supplement, which can actually be counterproductive. Um and as you say, um we want to improve gut health with these measures, but I believe there are some situations where probiotic supplements have a role. We know there are studies with athletes, for example, that if you take a probiotic, you're more likely less likely to get a viral infection which interrupts your training. Uh we've there are studies in school children showing it reduces the number of viral infections. Um so if you think your gut health isn't perfect, a good quality probiotic supplement, I think has a role. Um I wouldn't go for a weird and wonderful one. I as I say, in the study, we just chose the lactobacillus because it was safe. Um then I'm just looking through my notes here. So I'm yeah, making sure you have enough minerals and vitamins because you need minerals to enhance the antioxidant enzymes, particularly zinc, selenium, etc, which you can get that through a good diet. Um making sure you have enough oily fish and there's a couple of things at the end, psychological stress, of course, we always I always ignore. There are data to show that if you are stressed, that can affect your gut health. Uh and there's even an interesting study I came across having hot and cold showers. Um is uh is a a good way to sort of increase the brown fat which has the immune cells. So uh um so yeah, there's quite a few um things.
Dr Rupy: There's quite a few. Yeah. And and the reason for vitamin uh A and E and and how that might be counterproductive. Is that because the virus can almost use those elements to enhance their replication mechanism?
Professor Robert Thomas: Um well, we need those two vitamins, obviously, they're very important. In fact, a common cause of blindness across the world is vitamin A deficiency. So I'm not saying we shouldn't have a enough of them. But the studies which have given vitamin A and vitamin E supplements have all been disappointing. In in cancer, um there was a big ABTB study from Scandinavia which tried to look at the risk of skin and lung and head and neck cancers, and it had to be stopped because actually in the A and E group, um the number of cancers were increasing. In prostate cancer, we saw the same thing in the select study where there was an increased risk of of uh prostate cancer. And in in, you know, as you know, I'm a I do a lot with the sports medicine in the local university as well. And um, you know, athletes sometimes think that taking these direct antioxidants would improve performance because when you exercise, you do increase free radicals initially, which can be damaging to tissue. So their hypothesis was if I took vitamin A and D, I wouldn't get these free radicals. But actually, all they do is they block the natural adaptive increase in antioxidant enzymes. So you may get an initial tiny benefit, but overall, what you want is exercise to improve antioxidant enzymes, and it was blocking that. So actually sports performance was going down if you took those supplements. And that's been shown across the board. So, you know, I'm extrapolating those two data to COVID, uh but you know, common sense tells us is eat those foods containing those vitamins, but don't take any extra because you might be doing more harm than good.
Dr Rupy: I hope that was useful for a lot of people regardless with of whether you have long COVID or any other viral illnesses. I think this information around a polyphenol-rich diet could be super useful. As I said at the start, we're going to be chatting to Prof again uh about his new book, How to Live, which I think is absolutely brilliant. And you can find a lot of these uh the show notes and and the information on the study on the doctorskitchen.com/podcast. Do check it out.
