Episode 274 - Food and Cancer: The Truth

Chadi sits down again with Dr. Urvi Shah for an in-depth, evidence-driven exploration of the often confusing relationship between food and cancer. They dive into how nutritional research is actually conducted—and why it’s so challenging—while separating widely regarded myths from what high-quality data truly support, including nuanced discussions on processed foods, red meat, plant-based diets, ketogenic diets, intermittent fasting, and alcohol use. Dr. Shah also offers practical, science-backed recommendations for cancer prevention in the general population, as well as thoughtful guidance on how patients might approach diet and lifestyle changes after a cancer diagnosis.

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Transcript

SPEAKER_00 0:12

Hey everyone, it's Healthcare Unfiltered, and it's your host, Shadi Nabhan. I'm a hematologist and a medical oncologist with interest in all aspects of healthcare delivery, treatment, leadership, mentorship, and policy. Today we address an important topic: food and cancer. Anytime you scroll on social media, anytime you look at newspapers, anything, you're gonna find some opinions about the relationship between food and cancer. Certain foods, certain drinks may increase or decrease some cancers or not. Well, it's an important topic. And because this topic is essential, we have to look at data that really solidifies the information that we are looking at and consuming. I've invited Dr. Irvi Shaw, who works as a medical oncologist and a hematologist at the Memorial Sloan Kettering Cancer Center in New York, and who has really done a lot of work in the field of food and cancer. She has published, she has spoken on the topic, and I couldn't be happier than Dr. Shah joining me on today's podcast to tell us everything we need to know about food and cancer. Folks, don't forget to share this podcast with your friends and colleagues. Let them know about this episode and other episodes. Subscribe to the show. And if you write a brief review, it will go way along in letting others discover this podcast that is really essential. Healthcare Unfiltered comes to you every Tuesday morning at 7 a.m. Central Standard Time. Also, check out my website, chaddinaban.com. You'll see all of the episodes. You can reach me and offer any opinion, any advice or any suggestions on future podcasts and future guests. Also, and lastly, check out my books, Toxic Exposure, The True Story Behind the Monsanto Trials and the Search for Justice, and The Cancer Journey, Understanding Diagnosis, Treatment, Recovery, and Prevention. And stay tuned for two more books coming out in 2026. Well, without further ado, Dr. Irvi Shaw on Healthcare Unfiltered. Always happy to have you back.

SPEAKER_01 2:33

Thank you again for the invitation, Chathi. Looking forward to this discussion.

SPEAKER_00 2:37

I also know that uh you've been traveling um overseas, so uh it doesn't go unnoticed that you take time of your busy schedule despite the jet lag and join us. So thank you so much.

SPEAKER_01 2:47

Well, thank you for um uh giving me a chance to discuss this important topic with your audience. I appreciate you doing that too.

SPEAKER_00 2:56

So, what got you interested? I mean, you you when you take care of patients at Memorial, you do myeloma mainly, right?

SPEAKER_01 3:03

Yes. Or plasma cell disorders.

SPEAKER_00 3:06

Yeah, plasma cell disorders. This is what you do clinically. Correct. So um, and I've had you before on the show. I think for folks who are listening to you for the first time, you did have your own bout with cancer and think that you are doing very well. But tell me what got you interested in the topic of food or nutrition and cancer.

SPEAKER_01 3:24

I think my own personal journey was really where it all started for me. Um, going through training in medical school residency fellowship and realizing that we don't get much training around this, or we don't even think about it much when we talk to patients. So I didn't really spend much time discussing this with patients throughout my training. But when I was diagnosed, I found that friends, family members would suggest, oh, you should eat this food or avoid this food because it will be good for you. And then I realized like I as a doctor don't know enough about this, and I started reading about it more as a side hobby. I never thought it's possible to make a career studying this as an oncologist. So it was more a passion or interest. But when I started in Memorial Sloan Kettering, I wanted to do one pilot trial just out of my interest, looking at that, and that was our new prevention trial. And the success and interest in that trial from both patients, patient foundations, other doctors led to us building on this and me realizing that I could possibly make a career doing this. So I focused pretty much on studying modifiable risk factors in cancer. And now we have six dietary intervention trials, and when they're all completed, we'll have enrolled over 600 patients onto these studies.

SPEAKER_00 4:47

Amazing. So let's back up a little bit. How difficult it is to do nutrition studies for patients with cancer? And the reason I ask is because there are so many other things that we are doing at the same time. Yes. Right? Uh could be treatment, could be you're doing chemotherapy, radiation. If somebody has cancer, if somebody doesn't have cancer, they could be, I don't know, doing exercise, sleeping well, whatever it is. So, how are you able to study it in a way that you can conclusively tell people that if you do this from a nutrition or drinking standpoint, you will achieve that?

SPEAKER_01 5:26

So it nutrition research and lifestyle research is hard for multiple reasons. One is that, like, when you study a drug, the patient's either getting the drug or not getting the drug. And then the placebo, the same thing, they're either getting it or not. When you study something like diet or physical activity, every patient has their own baseline of what they're doing. So if you're trying to study a certain food group, they might already be eating that food group. So it's not like you're starting with a group of a control group that's none or not eating it compared to those that are eating it. So the effect size and also lifestyle interventions generally have a smaller effect size than a drug because a drug is more potent, but they also have less side effects than a drug. So often to do these studies to really look at meaningful clinical endpoints, they require much larger sample size. That's one thing. Two is you want the intervention arm to actually follow it almost completely the best they can, and you want the control arm not to follow it, so that becomes a challenge. And then funding is always a challenge with this too, because um usually and typically you don't get pharma funding for studies like this. And writing grants or bringing in funding to do large-scale studies can be a little bit more complicated. And I think that's the reason we don't see more oncologists or researchers doing it. I found that while I've been doing this for the last seven years, there have been a lot of researchers or um uh trainees who will reach out and say, Oh, we'd love to do the research you're doing, but once they hear about, okay, we need to write the grant or we need to figure this and the barriers to setting it up, I think many get uh find it gaunting and maybe decide not to pursue that.

SPEAKER_00 7:12

Yeah, understandably, it's not it's not it's not easy. So so, I mean, okay, how do we how do we try to understand diet-wise? Let's start with diet and food.

SPEAKER_01 7:24

Sure. So we actually published a um article in blood cancer discovery um end of last year, looking at how do we build dietary trials in hematologic malignancies, but it's applicable to any cancer, and thinking about all the different aspects when you're designing such a study, whether it is um the duration of the intervention, the type of intervention, the funding source, um the patient population, all of these aspects, which is some of them are very unique to dietary studies and some are similar to any trial, but we've tried to like break that down and summarize it into the key points that somebody would need to think about when they're designing such a study.

SPEAKER_00 8:07

Okay. So that was more of a like a setting putting a platform into how do we do nutrition type of trials?

SPEAKER_01 8:15

Yeah.

SPEAKER_00 8:16

Okay, so let's step back or forward, depending how you look at it. When you meet a patient, um when we say patient is somebody who has an actual disease, or you need a person who doesn't have a disease, are there things that an individual person who does not have cancer that could do to prevent some cancers from happening? I think we know smoking is one of them, but short of smoking.

SPEAKER_01 8:44

So that's definitely an important point. So when the American Cancer Society published a paper some years ago looking at modifiable risk factors for cancer, and about 40% of cancers could be avoided or prevented just through lifestyle and environmental changes. So things that they looked at and counted and calculated that's a four in 10 cancers related to smoking, alcohol, obesity, diet, physical activity, infections. So if we just did all the regular things in terms of vaccines to prevent some infections, avoiding risky substances, eating a healthy diet and lifestyle changes, we could potentially reduce our risk by 40%, which is I think quite significant. It's almost one in two cancers.

SPEAKER_00 9:34

Okay, but that's broad, right? That's broad. Um, and you know me, I'm gonna add pesticides here on Roundup because I think Roundup is an awful thing that people still spray and it causes um some cancers. So but uh but let's uh let's step back, let's take one at a time. Diet-wise, what can somebody do from a diet? I know healthy diet, but what does that mean?

SPEAKER_01 9:58

So um the American Institute of Cancer Research has evidence and guidelines around cancer prevention recommendations, and even the American Cancer Society. And six out of those ten guidelines are around diet. Um, they focus on avoiding refined sugars or sugary drinks and beverages, avoiding processed meats and red meats, avoiding um processed foods, increasing consumption of fruits, vegetables, whole grains, beans, seeds, and nuts. Supplements are not going to be the answer to prevent cancer. They have that as one of the recommendations. And um, I think these are the main ones. And then, of course, alcohol would be the next to avoid.

SPEAKER_00 10:43

Going back to the diet before we talk about alcohol, when we say you know, avoiding red meat or things of that nature, is that complete avoidance or can I have some steak every so often? Or a burger? Or a burger or a burger, Urby, please?

SPEAKER_01 10:58

I think it's a risk benefit that each person needs to make a decision for. Um, processed meats have been considered by the IARC as a group one carcinogen, means definitely causes cancer. Red meat is a probable carcinogen, means most likely causes cancer. And the um increased risk is seen with as little as about 50 grams per day of processed meats or 100 grams per day of red meat. And those that do eat meat regularly probably eat 50 to 100 to 200 grams per day often. So I think limiting the amount to maybe saying it's only on special occasions or actually considering shifting the kind of meat a person eats, I think those changes could go a long way.

SPEAKER_00 11:50

Like, what do you mean the kind of meat uh they change to?

SPEAKER_01 11:53

So we talked about red and processed meat having the most clear evidence. So thinking about whether they're moving towards fish or eggs or um uh chicken or poultry. Of course, um the best uh evidence is for substituting plant proteins over animal proteins. So if somebody is willing to do that or go one step further, I would recommend doing that for risk reduction. But I think we're we have to see where each person is and what they're they think is possible for them.

SPEAKER_00 12:28

Okay. Um other things in terms of diet. You have written and published and studied plant-based diet. Can you explain to us what plant-based diet is and and what what's what's what does the evidence show?

SPEAKER_01 12:42

Sure. So uh our first study that was just recently published in Cancer Discovery looked at a high fiber plant-based diet in patients with a pre-cancer or precursor state to multiple myeloma called Mgus and smoldering myeloma. What we saw in these participants is that when we shifted diet quality from a Western diet to a high fiber plant-based diet, it improved dietary fiber intake significantly. They were able to adhere to this diet. It went from their calories being 20% of their calories being unprocessed plant foods to 90% of their calories on intervention being unprocessed plant foods. And then even one year later, it was about 60%. So we were really able to shift dietary patterns on the intervention and beyond the intervention, close to one year later. We saw an improvement in dietary fiber intake, improvement in quality of life, improvement in patient-reported outcomes such as GI issues, um, mental health issues, sleep, um, metabolic changes, confidence, patients were able to stop prescription medications and save an average of $65, the four patients that stopped medications. Um, what's most important and interesting to oncologists was could this delay progression? Now, this was a small study, but we did see that two patients who had clearly rising M spikes before going on intervention had stabilization on intervention. And we calculated a rate of change of this M spike for 20 months on and after intervention to 20 months before intervention, and that was significant, the p-value suggesting that that may have delayed progression. For example, there was one patient who had an M spike of 0.2 that increased to 1.2 over the course of five years from 2016 to 2021. During that period, that patient actually had lost weight on a GLP1 drug for diabetes, but was also on insulin. So one might say, like, okay, they've lost weight, but their but their M spike still progressed during that period. Then they went on our study. In a month, they were able to stop insulin, they changed dietary pattern, lost an additional amount of weight to normalize their BMI. And then we see a stabilization of the M spike over the course of the next few years. So that to me suggests that the dietary pattern is not just working through weight changes, but it's working through the microbiome and other mechanisms too, such as insulin resistance and those aspects. And then we looked at all these different uh biomarkers or key cancer risk markers, as you would say, that we know are associated with progression. So we looked at things like insulin levels, which we saw reduced and went down despite them eating more carbohydrates than usual, but these were complex carbohydrates and not refined carbohydrates. We saw an improvement in gut microbiome diversity. And you're probably aware that in cancer studies, diversity is associated with progression, free survival, and overall survival, higher diversity, better outcomes. This may be one of the few dietary studies in a pre-cancer population that has been able to show that actually, with an intervention, we can change this biomarker and improve diversity. We also improved in increased butrate producers or bacteria that make these short-chain fatty acids that have anti-cancer, anti-inflammatory effects. So we were changing the composition of the microbiome through this dietary pattern shift as well. And other aspects on the immune system. So you may say, was there any change in immune cell subsets? We saw the C-reactive protein levels significantly drop in all patients by one year, but even in the seven that it was clearly elevated, it dropped by 50%. Then the subsets or immune subsets, the anti-inflammatory immune subsets like classical monocytes increased, and the inflammatory ones like non-classical monocytes reduced. And lastly, when we looked at the bone marrow, so this may be the only trial that has done single-cell RNA sequencing on paired bone marrow samples after a dietary intervention. And what we showed is that there's a shift in the immune cell populations. There is increased innate immunity in the bone marrow because the granulocyte-monocyte progenitors increased. But in the blood, there are less circulating neutrophils, suggesting less inflammation and need to circulate, but enhanced immune potential in the bone marrow. And then lastly, we saw the crosstalk between cells. So the myeloid compartment cells, so like the monocytes, the MDSCs, these were interacting at baseline mainly with the exhausted CD8 T cells. One year later, their interaction was much more significant with the cytotoxic CDA T cells and natural killer cells. While this is an exploratory analysis and what we call cell chat or cell interaction analysis, we do see a shift in the crosstalk or function of the cells too. So, in summary, our dietary intervention could change weight, quality of life, inflammation, microbiome, and metabolism, potentially delaying progression in some patients.

SPEAKER_00 18:24

I read the paper. Congratulations. Yes, it's a small it is it is a small, but uh you've done so much in terms of correlative uh studies with just 23 patients. So um for sure, I mean I have not seen that much analysis on a small cohort of patients. So congrats for that. But my question to you when you do something like this, how do you assure that patients are indeed following the diet modification you requested? Because you're not with them 24-7.

SPEAKER_01 18:54

Yes. And meaning I think some of it is these objective biomarkers significantly changing, like weight going down by 7%, other things, it shows you that they've made a change, but of course, we want to measure it as well. So we do this through multiple methods. Um, there these are validated methods. So the food frequency questionnaire is one method where you ask people to complete a survey of a few hundred questions. It takes about 30 minutes and it looks at the dietary pattern over the past year, and you can do that at multiple time points. That's one way. Um, in dietary intervention studies, while we did those surveys, we also do a more detailed analysis called a 24-hour dietary recall. So at specific time points, we will call the patient and ask them what they ate in the last 24 hours and document that into uh software that can then calculate all the macros, the micronutrients, all of those aspects. So we know exactly how much fiber they're getting and other aspects. And then we use that to uh calculate compliance or adherence to the diet. And we have a really detailed table in the supplement of the paper on all of these aspects of the diet. So you can see at baseline what their diet was like 12 weeks, 24 weeks, 52 weeks. So you can see the significant changes there.

SPEAKER_00 20:13

Now these were patients who had pre-myeloma, kind of. Um, and uh the data suggests that you are preventing that progression into myeloma, obviously. Do you think that translates into other diseases, whether it is solid tumors or other hematologic malignancies, or do you believe that the findings you you have are just specific to myeloma?

SPEAKER_01 20:36

So I think um I think that it can be generalized to other diseases. However, I think the degree of effect may be different for different cancers, in the sense that when we I think about diet, I think about um diet affecting the immune system, strengthening that, and dealing progression, whereas the cancer is progressing through genomic approach mutations. So if there's a cancer that's highly genomically driven and not really being able to be controlled by the immune system, then maybe the dietary factors might play less of a role in those cancers. But other cancers that are more um due to an immune system that's less robust, then the dietary changes that modify the immune system and enhance it may have a greater effect. And I think we know that from the aspect that not all cancers are associated with obesity, or not all cancers have the same risk factors. So that tells us that maybe diet plays a more significant role in some cancers like GI cancers, maybe obesity related cancers, and maybe a smaller role in some really aggressive, viral driven cancers or other aspects. But that being said, I think across the border in generalizable terms, I think. It could reduce risk or prevent um or de improve survival for patients overall. So I think if we don't have data in general, we have data in population level studies if we don't have clinical trials.

SPEAKER_00 22:15

Tell me about uh the keto diet. The keto diet, uh, there's a lot on there. I've done a couple of uh shows on keto diet, but uh it's one of these. I want to specifically hone in what do we know about keto diet and cancer, and what do we know about intermittent fasting and cancer?

SPEAKER_01 22:33

Sure. So we published a paper in JAMA oncology in 2022 looking at plant-based versus ketogenic diets. The reason that we wrote that paper was when I was trying to design our first dietary trial, I looked on clinicaltrials.gov and I typed in to see all the dietary intervention studies. What I found was very surprising to me that the majority of studies, about five times as many ketogenic diet studies were there on clinicaltrials.gov for cancer compared to plant-based diets. And then when I looked at epidemiologic studies or population studies based on which we should be doing interventional trials, I see that plant-based diets are associated with a 15 to 20% lower risk of cancer in many huge cohort studies. So we're seeing this diet metrically opposite pattern where Epi studies are telling us that fiber-rich dietary patterns reduce cancer risk. And then we are doing interventional studies in cancer patients with a ketogenic diet, which doesn't have any observational data. So to me, that led me to think about what is common between these two diets and what is different and how might they reduce cancer risk or help. So I would say the common aspects between these two diets would be things that both diets will lead to some weight loss, possibly because you're avoiding like refined carbohydrates or things like that. They will help with inflammation and uh um insulin resistance, probably. The differences is that in a ketogenic diet, because the diet is an extremely low carbohydrate diet, it is not very physiologic and difficult for people to follow often. And many times they think they're doing a ketogenic diet, but in fact, they're just doing a low carbohydrate diet, and then they're not getting the benefits of the ketone bodies. The ketone body or beta-hydroxybutrate that is the main molecule that a ketogenic diet benefits from is um got anti-cancer, anti-inflammatory effects, effects on the immune system that may be driving some of those benefits. Take that molecule, and the parallel to that molecule in a plant-based diet is butrate. So beta-hydroxybutrate in a ketogenic diet, butrate in a plant-based diet. Butrate is made by the microbiome in the gut. And high fiber-rich foods increase butrate producers and increase production of butrate. Butrate also has anti-cancer, anti-inflammatory effects, and there are numerous studies, including in our cancer discovery paper, where we've actually looked at the effect of butrate on myeloma cell lines and in my mice showing the anti-myeloma and anti-cancer effects. So though that molecule is increased in a plant-based diet. The other things about a plant-based diet is because it is plant-based foods and fiber is the fiber only comes in plant foods that are unprocessed. A plant-based diet is rich in fiber, that is important for gut microbiome health. Ketogenic diets, because they're avoiding carbohydrates, are often very low in fiber and high in meat and saturated fat. Um, one study in healthy individuals was from uh the NIH. This was that they put patients in a metabolic chamber and they put them either on a ketogenic diet or a vegan diet. Basically, they were trying to compare the low carb to the low-fat diet. And for two weeks, they would be on each diet and then swap. And because it's a metabolic chamber, understand that every calorie of theirs is measured and they are like admitted for that time. So you know exactly what they're eating and what food they're given. They both lost weight in the ketogenic and the vegan diet, but the difference in the weight loss is important and telling that in the vegan diet, because it's a low-fat diet, they lost fat mass. In the ketogenic diet, which is a high fat diet, what did they lose?

SPEAKER_00 26:45

Muscle.

SPEAKER_01 26:46

Muscle and water, because it was fat-free mass. And so to me, that's healthy individuals, which maybe may be okay, but if it's a cancer population, to me, that is very concerning because carceia, we know muscle mass, all of those things are issues. So personally, I think when a when a ketogenic diet study is done, body composition must be measured because that we need to see what's happening in these patients when we do that. I think a ketogenic diet, maybe in the short term, if a patient feels might be something they could do. But long term, the other risk with a ketogenic diet is also cardiovascular risk because of the high saturated fat. There are enough studies showing that too, that we increase it. And in cancer survivors, cardiovascular disease is a risk factor, and we might actually be doing long-term harm if that risk increases.

SPEAKER_00 27:43

Okay. So to me, just so it's not, yeah, yeah, keep going. I was gonna say you would push, like if a cancer patient says I want to do a ketogenic diet or a healthy pair of ketogenic diet, you would say it's okay short term, but it's not something you'd recommend long-term.

SPEAKER_01 27:57

Yeah, exactly. And even short term, there are there are other ways to lose weight. You could do it as a low carb, where you're I I think every healthy diet should avoid refined carbohydrates, right? Whether it's a ketogenic diet, a plant-based diet, Mediterranean diet, like the common theme from all these is avoid processed and refined foods. So I think people feel good when they do a ketogenic diet because they are avoiding all carbs. So all the cookies and croissants and cakes go out.

SPEAKER_00 28:26

I wouldn't feel good about that. Well, I wouldn't feel good about that. I won't like that.

SPEAKER_01 28:32

Yeah. So I think that's one of the challenges with um ketogenic diets. And I think if it needs to be studied in cancer, these aspects need to be thought about and studied more carefully. And that's part of, and then the other aspect is the microbiome, uh, right? That we are now just scratching the surface in oncology about the benefits and the importance and the role the microbiome plays. But time and again, and research study after research study looks at what dietary patterns and what foods improve microbiome health. And one of the most important dietary components is dietary fiber, and less than 5% of the US population get enough dietary fiber. Yeah, so um one thing that and and to get enough dietary fiber, we need to increase consumption of unprocessed plant food.

SPEAKER_00 29:28

For sure, for sure. Intermittent fasting, tell me tell me a bit about that.

SPEAKER_01 29:33

So uh intermittent fasting, when we look at it, um some studies have looked at it um just thinking about it as okay, we don't change dietary pattern, but we just ask patients to fast during a window. It is in one way a method of calorie restriction because you're just eating during a shorter window. However, some patients will end up eating more during that period because they're really hungry and then they might say, okay, I'm just gonna eat whatever I want. So if the diet quality is getting more unhealthy or not changing, I don't think that intermittent fasting has as much benefit as changing diet quality. Um, there is quite a bit of data, however, with the fasting mimicking diet, which is a type of intermittent fasting, where um done by research from Dr. Walter Longo's group, where patients will for five days do an ultra-low calorie diet of 500 calories on day one and 250 on day two to five. And they do this for every for five days every cycle of chemotherapy. There is now emerging evidence that that fasting mimicking diet, and during those five days, the food that they provide in the fasting mimicking is basically a plant-based low-calorie diet for five days. And then the rest of the 25 days of a cycle, you can eat whatever you want. And what they show is that that kind of resets the immune system and improves metabolic parameters and may actually enhance response to cancer therapy. So they've looked at that in breast cancer. So I think that data is emerging and maybe we will see some more, but that's mainly with the fasting mimicking diet. I have not seen as promising data with like daily intermittent fasting for it. But I think it's important that the circadian rhythm, and we know that that's important. So eating within a defined time is helpful where we're thinking, okay, we're not going to eat after a certain time every day. So I think intermittent fasting brings that regimented nature to eating and not snacking at any time, which could be beneficial.

SPEAKER_00 31:57

So, I mean, a lot of us when um you know, when patients are diagnosed with cancer and they're asking for diet modifications, I mean, our maybe our poor uneducated recommendation is usually eat healthy and balanced diet, but enjoy your food. I mean, you already have cancer, you've been there, you already have to get chemotherapy, you've been there, and it's just it's not fun, and some of the chemotherapy affects your taste buds and so on. It becomes a little bit for us challenging to kind of tell deprive, I guess, a patient who is undergoing chemotherapy. So I I admit, I mean, I often just would tell a patient, you know, look, uh eat healthy, try to avoid refined sugars, like you said, and but enjoy food because God knows, you know, what you're going through.

SPEAKER_01 32:52

So that's a great point. And I think that just the point you're making is that we need to individualize this and we need to think about the patient in front of us. Like, even though I do this research, it doesn't mean that I'm telling every patient that they need to change their diet because there will be some patients who are not yet receptive to it, they're overwhelmed with the current chemotherapy or treatment, and I'm not going to try to add more things to their plate at that time. But I think there are other patients who really want this. And like you said, eating a balanced diet. Uh, I've had patients tell me that my oncologist said, just keep eating a balanced diet. And I realize the onus or the responsibility is ultimately on me to understand what that is, because we know most people don't know what a balanced diet is. And even many physicians are not aware. And most people don't follow dietary guidelines, recommendations, and things. So I think starting small and thinking about like one or two tips you can tell a patient. Sometimes I might just say, like, okay, add a cup of beans every day to your diet. You're not changing too much, but you will get 15 grams of fiber if they are on the average of the US population where they're getting 10 grams. If they get um 15 more grams, they will reach the recommended daily intake of it. And then also that has a good amount of protein too. So, you know, something like that, or thinking about tiny swaps that they could make in terms of what they're already eating, where um instead of having a processed meat in the sandwich, maybe they will change it or swap it out for hummus or a different kind of meat that's less processed or something. So those small changes can add up. What lastly, I'll say is that we think that dietary changes are very difficult for patients to make. And it is true if we're not guiding them and coaching them, it is difficult. But what I have found in our studies, and that has been surprising to me as well, despite doing them, is the number of patients that tell me that this has been life-changing for them. And the number that are actually doing this even after the study is over, like a year later, two years later, when we follow them in the clinic, they're like, oh yeah, we're still following many of the things we learned, or all of the things we've learned on the study. Because once they start feeling better, then they're able to continue it and they've learned also the foundation of how to do it. And I think the challenge is that we don't have a medical system that makes it easy for us to really help patients make these changes. So we're able to do it because we're doing it through our blood trials. We're providing the food to them. We have personalized coaching with a dietitian, and all these aspects help to make the behavior change. And once they've made the behavior change, seen the benefit, then they are ready to do it on their own, whether we give them the food or not, because now they they feel better.

SPEAKER_00 35:50

Let's just like a few things that are, you know, as we wrap up, because this is, I mean, you have to come back again, but just a few other things.

SPEAKER_01 35:58

Yeah.

SPEAKER_00 35:59

Coffee. We hear a lot about coffee. There's some studies, uh, coffee, yes, coffee, no. I mean, we lost track. Um, is there really any evidence about coffee's association or not association with cancer?

SPEAKER_01 36:13

I think uh in general, coffee has is is uh a healthy food. A lot of people feel like coffee may be associated with like they shouldn't have it, but coffee has um the plant chemicals that are associated with better outcomes and better microbiome health in many studies. So, in general, I would say black coffee without the sugar and without the milk, if possible, because the milk will reduce the absorption or of the healthy aspects of coffee.

SPEAKER_00 36:44

Alcohol is clearly associated with cancer because we we know that. Um, and I think in some estimates, 6% of cancers uh are caused by alcohol. My question to you is there a safe minimum amount of alcohol that somebody could actually drink? No, I'm not I don't drink, so it doesn't matter to me, but many of my listeners do, especially if they're watching or listening, they have to drink to tolerate me. So uh what can you tell them?

SPEAKER_01 37:10

I think uh every person needs to decide how much they enjoy it and what's that limit for them. Alcohol clearly is associated, and now the new guidelines say there's no safe limit for alcohol consumption. Uh when we look at population studies, we do see sometimes that people who drink a little bit have better outcomes than people who don't drink at all and people who drink too much. And the reason is because probably the people who don't drink at all, some of them used to drink and are much sicker, and so now they're in the group that doesn't drink, or the people who are more social and drinking a little bit are getting the benefits of social connection through that drinking and being out with friends. So I would say that um all of this evidence we have to understand what's possible and feasible for us to do, and the less is better, of course.

SPEAKER_00 38:02

Some people are absolutely convinced that stress causes cancer.

SPEAKER_01 38:09

It's a very hard thing to study compared to diet or physical activity, which are already hard, but they're still measurable. Stress is much, much harder to measure and study in an interventional trial. But I think that we know that stress affects the immune system, and we know the immune system drives cancer. Um, so it is certainly possible.

SPEAKER_00 38:34

How about sleep? My last question.

SPEAKER_01 38:36

I think same as um as uh dress.

SPEAKER_00 38:40

Anything I should have asked you, Urby, about food and cancer or anything like that that I completely forgot.

SPEAKER_01 38:48

No, um, maybe we just one thing would be like I think soy and uh breast cancer, it's a common myth that many oncologists will tell patients that you had breast cancer, so you should not eat any soy products or tofu. Um, what the evidence shows time and again, and it's even in the American Cancer Society report from a few years ago, there are three paragraphs on it, that actually soy consumption reduces breast cancer risk. And because soy has, even though it has estrogens, these are phytoestrogens or plant estrogens that actually are milder or weaker estrogens than our own estrogens, and so they actually reduce cancer risk, not increase it. So I would not tell patients with breast cancer to stop consuming soy. Maybe soy protein isolate or processed soy products could be avoided because they might be more concentrated forms, but the ones that are like tofu, tempeh, soy milk actually might reduce risk of recurrence and improve outcomes.

unknown 39:51

Dr.

SPEAKER_00 39:51

Urvisha, this is a topic that is so difficult and challenging. You always are generous with your time telling us what to do and what not to do. Um I think I'm gonna still have a little bit of French fries every so often.

SPEAKER_01 40:03

I I think that's perfectly fine.

SPEAKER_00 40:05

I may I think if I text you a picture of it, you may have a heart attack like that.

SPEAKER_01 40:10

That may not be fine.

SPEAKER_00 40:12

Well, thank you so much for coming on Healthcare Unfiltered.

SPEAKER_01 40:15

Thank you so much for the invitation, Chadi. Nice chatting.

SPEAKER_00 40:27

Thank you, Dr. Shah, for joining me on Healthcare Unfiltered. I really appreciate the time, folks. This is a very difficult topic. It is an important topic: food and cancer, what type of nutrition we can modify. I would put that in the category what are the life-modifying factors that we could do to reduce the risk of developing cancer or of pre-malignant conditions becoming cancerous. Dr. Irv Shaw at Memorial Salon Kettering does a lot of research on this, and I promise you that she's gonna come back on the show again. Before I leave, I want to make sure you can subscribe to the show. You can find this everywhere, and you can follow me on Twitter, Instagram, YouTube, Facebook, TikTok, and everywhere you can zoom podcasts or social media. Check out my books, as I mentioned earlier. And before I let you go, I'm gonna leave you with a saying by Winston Churchill. We make a living by what we get. But we make a life by what we give. Until next time.