How Obesity Raises Cancer Risk with David Heber

James Hill:

Welcome to Weight Loss And, where we delve into the world of weight loss. I'm Jim Hill.

Holly Wyatt:

And I'm Holly Wyatt. We're both dedicated to helping you lose weight, keep it off, and live your best life while you're doing it.

James Hill:

Indeed, we now realize successful weight loss combines the science and art of medicine, knowing what to do and why you will do it.

Holly Wyatt:

Yes, the “And” allows us to talk about all the other stuff that makes your journey so much bigger, better, and exciting.

James Hill:

Ready for the “And” factor?

Holly Wyatt:

Let's dive in.

James Hill:

Here we go.

Holly Wyatt:

Today's topic might surprise some people. I think most of us know that obesity is linked to type 2 diabetes, heart disease, and a whole bunch of other things, but I don't know that we know or we think about the fact that it's also linked to cancer.

James Hill:

Yeah, so if you've ever wondered, does my weight really matter beyond the scale? If you have a personal or family history of cancer, this episode might be really useful for you.

Holly Wyatt:

Yeah, and to unpack this critical topic, we've invited one of the world's leading experts on clinical nutrition and cancer prevention.

James Hill:

Yeah, Holly, our guest today is Dr. David Heber. Now, David really is a pioneer in nutrition research. You know, we've said before, we bring some of the world's best people in, and we've got one today in Dave Heber. And Dave and I go way back. We've worked together probably for almost half a century, and he has been a leader in nutrition. He founded the UCLA Center for Human Nutrition back when few people were looking at this. And he spent decades researching how food and weight impact chronic diseases, including cancer. He's authored four books, including The L.A. Shape Diet and What Color Is Your Diet? And he's made it his life's work to make science understandable and actionable for the public. So you're in for a treat today.

Holly Wyatt:

Yeah, David, we're thrilled to have you here. So let's start at the kind of the very beginning. Can you explain in simple terms how being overweight or obese increases cancer risk? Why there is this association between the two?

David Heber:

Well, you know, I look upon obesity as a systemic disease, something that affects the immune system. It affects many. We know about diabetes and heart disease, but people were surprised about obesity. And where we get the clues for this is from population studies, epidemiology.

David Heber:

And this is where this thing first popped up. And what they found was significant increases in risk of cancer for obese postmenopausal women for breast cancer and for other cancers that we can talk about. But the first one, the first signal was really postmenopausal breast cancer. And it made a lot of sense as to why that one popped up. As you know, with menopause, a lot of problems arise. Bone health problems, loss of muscle occurs, and increase in body fat, mostly in the upper body, and particularly breast fat. It turns out that women who have excess breast fat or undergo a breast reduction have it in the upper outer quadrant. Well, it turns out the place where most postmenopausal breast cancer occurs is at that junction of the upper outer quadrant with the breast cancer cells. So for a long time, we've been looking at how these fat cells are more than bags of fat, but actually are endocrine and inflammatory immune tissues that communicate with cancer cells. And I'm a big fan of looking at the whole person as opposed to looking at individual cells. We learn a lot by looking at cells. But I think when it comes to obesity and cancer, when we get beyond the epidemiology, then we have to take an integrated view of the effect of obesity on cancer through hormones, through inflammation, and other ways.

Holly Wyatt:

So it sounds like there's more than one mechanism probably going on. But it's the fact that these cancer cells and the fat cells communicate probably by many different ways. Is that kind of a simple way to think of it?

David Heber:

Yes, but it's not disconnected from the higher level. So you can almost think of it as a government. You've got your local government, your state government, your federal government, right? And so you've got your local cells communicating with these stromal vascular cells, which are a lot like adipocytes, and they're communicating, and there are lots of signals going back and forth. So those cells have been shown to turn on enzymes in the cancer cell. And then within the cancer cell, they have abnormal metabolism. Jim and I started studying this back in the 1970s, that cancer cells are abnormal in how they use amino acids and how they grow. They're basically cells that grow but don't stop growing. Most normal cells proliferate or grow for a while, and then they die after about 21 cell divisions. But what happens with cancer cells, they're immortal. A famous case of Helen Lane was a patient with breast cancer, and her cells were passed from laboratory to laboratory and cultured for generations. And they're called HeLa cells.

James Hill:

They survive well.

David Heber:

Yeah. And that's where all the genetic theories of cancer got started. And nutrition was always thought to be kind of not important. We're busy here, Dave. Get lost.

James Hill:

Yeah. I remember, Dave, you were one of the few people studying that early on. And now it's the hot area.

David Heber:

Oh, yeah.

James Hill:

You mentioned breast cancer. There are some cancers that are more associated with obesity than others. Can you talk a little bit about what we know there?

David Heber:

Sure. One of the others, of course, postmenopausal breast cancer we mentioned, but prostate cancer is an interesting one. It's one that I've worked on with prostate cancer now for many years. And it turns out that if you're obese, not only does your cancer grow more quickly, your mortality is increased. And the interesting thing in prostate, a lot of people aren't aware of this, is there's a periprostatic fat tissue behind the prostate gland. And we've done some studies that show that immune cells will migrate in there and put inflammatory signals into the prostate gland. When you look at a prostate, there is inflammation. There's something called proliferative inflammatory atrophy right around the areas where the cancers form. So they do these biopsies now. And what I'm into right now is prevention, both for women's breast cancer and for prostate cancer. We have the tools to do that. And for colorectal cancer, that's another one where there's been very good evidence. Also, endometrial cancer is another one. So various specialties have ways of screening for these and getting to them before they develop.

James Hill:

Great.

Holly Wyatt:

Are there some cancers that don't seem to be increased, maybe aren't associated with overweight or obesity?

David Heber:

Yeah. I mean, I think if you look at cancer, there are a number of etiologies, inherited cancers, things like testicular carcinoma in men actually starts out in utero, and it's a teratoma. So that's not affected very much. And we have very good chemotherapy for that particular disease. Most common cancers, malignant melanoma, melanoma is affected by obesity, pancreatic cancer, kidney cancer, gallbladder cancer, gastric cancer. Esophageal is really interesting because the type of cancer changed because with obesity, a lot of people have acid reflux. Eat too much food after dinner and lie down. Next thing you know, you're looking for the Tums and the acid pills. But that has changed what was squamous carcinoma in the esophagus due to smoking and alcohol into adenocarcinoma due to the acid causing that bare esophagus. So there's been a whole change.

Holly Wyatt:

I think that's a point in point. I think some people do think about it associated with certain cancers, but almost, I mean, maybe not every cancer, but almost all cancers are showing some type of association increased risk, which leads me to my next question. Is it a small risk? Is it a big risk? Can you give us any idea how much our risk is increasing.

David Heber:

Well, there's some interesting studies have been done and shown that postmenopausal women who lose 22 pounds, 10 kilograms in Sweden, that they actually reduce their breast cancer risk by 50%.

James Hill:

Wow.

Holly Wyatt:

Wow.

David Heber:

Yeah. And there are other studies that show 24%. So they think that about 20% of all cancers are associated with obesity and that some cancers even more so. So, these changes are multiple and the ultimate cause of cancer is there are about 100 genes called oncogenes or tumor suppressor genes, which are mutated. And this was discovered in the early 1970s. And these genes either turn the cells on like a light switch that's on all the time and it never goes off, or they stop suppressing tumors that arise spontaneously. That generated a whole generation of targeted oncology that we have today, which is wonderful. And all unfortunately caused kind of a antagonism between the genetic researchers on cancer and us nutrition diet lifestyle folks.

James Hill:

Yeah.

David Heber:

And so, you know, it's like we're the real scientists. You guys soft science, you know. Don't bother me. I'm busy. But what happened is we found out now the gene expression is influenced by your diet and your environment and what's called the exposome what you're exposed to. And there are differences in lifespan between people who live in a poor neighborhood and people who live in a rich neighborhood, a lot of which is mediated.

Holly Wyatt:

Love this. It's showing, once again, the combination between behaviors and genetics. It's not one or the other, right? It's both. And we talk about that so much in terms of obesity even, right?

David Heber:

Well, it's come a long way. Obesity is now, I think, the number two cause of cancer worldwide after tobacco. Number three is alcohol, which we'll talk about. Finally, these guys got it. You know, it took a long time in heart disease. People remember late 1990s for heart disease.

James Hill:

It did take a long time. And you mentioned heart disease, Dave. One of the things that we know about some of these metabolic consequences of obesity, it depends on where the fat's located. Fat in the belly or the visceral area is more negative. Is that true of cancer as well?

David Heber:

Absolutely. It turns out that 70% of the immune system is around the intestines and the enteric fat around the intestines is visceral fat. So when people gain abdominal fat, we measure it with a waist circumference or whatever. Other people actually do an MRI. My friend Jimmy Bell in England had something called TOFI, thin on the outside, fat on the inside. And basically, if you look inside the abdomen, you can find people who look thin, but they have type 2 diabetes and they have excess abdominal fat. People with an Asian background typically have abdominal fat and all the South Asian and Asian countries. Look at India or you look at Vietnam, places like that. It turns out that the susceptibility to heart disease influences what we see in terms of cancer statistics. So, Hispanics tend to have a lower relationship of obesity to cancer, but they have a higher susceptibility to heart disease. You can't die twice. So if you die of heart disease, we're lost to any correlation with obesity.

Holly Wyatt:

That is true.

David Heber:

And then African-Americans also seem to be more susceptible. And whether that's due to the exposome, the type of diet and lifestyle they've had, the higher incidence of type 2 diabetes as well, which could be related in the African-American community, higher insulin levels, higher insulin-like growth factor levels that stimulate tumor growth. So you can start to see that this tree is kind of complicated.

James Hill:

Yeah, it is complicated. And hopefully we're going to sort it out a little bit. David, we've talked a lot about weight and the importance of weight to cancer. But you were one of the early people that started looking at what we eat that may impact cancer, development of cancer or prevention of cancer. Talk a little bit about nutrition. Maybe... Not totally independent of weight, but what people can do with their diet to reduce the risk.

David Heber:

Right. Well, as you know, I wrote this book in 2001 called What Color Is Your Diet? And the reason is I talked about the brown-beige diet of United Airlines. I always talk about that in my thoughts. And now today it's called ultra-processed foods. But it's been around for a long time. If you're going to make a meal that costs a dollar and 35 cents, you don't have a lot of room for broccolini and stuff. So it turns out that there's a lot of data on the effects of what I like to call phytonutrients that are found in fruits and vegetables. A lot of people call them phytochemicals because they're more coming from a drug approach. But for example, the pomegranate has 120 different chemicals in it. And when you look at every single fruit or vegetable, there are hundreds of these. And so there are 100,000 phytonutrients. And the whole thing, as with anything in nutrition, is diversity. So I recommended seven servings a day of fruits and vegetables. I worked with a program in California called Five a Day for Better Health. 80% of Americans don't eat five fruits and vegetable servings a day at 100 grams per serving.

And some don't eat a fruit all day long. So a lot of the fruit and vegetables that they should be eating, they're not eating. And this has been a big program of mine to try to do this. And, you know, I consulted with the fruit and vegetable industry. And unfortunately, it's based on taste, cost, and convenience, just like packaged foods. And people don't think about the calories in fruits and vegetables. So the number one fruit in America is the banana, which a large banana can be 200 calories. And most of the genetics of the banana is about making sugar. And we know how good that is for you.

James Hill:

Right.

Holly Wyatt:

Yeah.

James Hill:

Right.

Holly Wyatt:

So you talk about a bunch and you use big numbers. Do you think keeping a variety is important or, you know, and why? Why do you think a variety is important?

David Heber:

Because there are different classes. So there have been a lot of color diets over the years. You know, dieticians have written, arbitrarily assigned some foods to be blue, some foods to be yellow, et cetera. What I did in my book was to link them to particular families. And I first started with tomatoes and lycopene that I'd been in a New York Academy of Sciences talk. And the guy talked about the red family and tomatoes. And I thought, hey, red family, blue family, orange family. So the carotenoids would be the orange family is carrots, squash, pumpkin.

The red family tomatoes is tomato soup, tomato juice, but it's also watermelon. And it's red blood oranges. So you start to see that these colors kind of move around. And they're all potent antioxidants, number one. But these antioxidants have other properties. They interact with enzymes in your body, your metabolism. They induce things in your liver. So, you know, a lot of people like to talk about drug-nutrient interactions and don't drink grapefruit juice if you're on a statin, right, or heart cholesterol-lowering drug. Well, it turns out that those enzymes in the liver were never designed for—there were no statins 50,000 years ago, 100,000 years ago. Those are phytonutrient metabolizing enzymes. So your body is expecting these things. So one of the ways that you can cause cancer in 100% of animals is to deprive them of all the phytonutrients that are stimulating these methylating enzymes. And you get liver cancer in 100% of animals. So our bodies, and I came up with what's called the xenobiotic theory of cancer, that you need to have these external things. And now that story's been changed. So for about 10 or 15 years, we've known about the microbiome.

And now we know the microbiome, it's all those phytonutrients. And then that impacts the immune system, which happens to be right next door in the intestine. And then that is connected to the brain. So now the whole body is working really well.

James Hill:

It really is connected, Dave. And one of the things you mentioned before that most Americans don't get enough fruits and vegetables and survey after survey shows that. And it's been very tough to increase that. I'm going to set you up here because I know that some of the work you've done is how innovative things we might do doing fruits and vegetable intake. You and I work together, for example, on herbs and spices. Tell us about some of your work there and what you think we might do in an innovative way to get people to eat more fruits and vegetables.

David Heber:

Absolutely. I mean, you know, I think that one of the things about these one class of compounds within fruits and vegetables is very beneficial are called polyphenols. That's a big word, but they're bitter. And, you know, bitter substances have often had a reputation for being healthy. So if you look at Chinese culture, bitter melon is something they use to control diabetes. And my father-in-law used to drink this stuff called zwack from Europe, which was like a resin that was very bitter. And they would take it when they had a cold, thinking it would help cure the cold. So bitter things are good for you, but they don't sell real well.

James Hill:

Right.

David Heber:

So the least popular vegetable would be broccoli and Brussels sprouts. Those are really good for you. They have these glucosinolates in them. Very good for you. So what can you do to change that? Well, we spice them. And we've done studies to show that people like those better. And we actually had something I called my magic plate. It's actually called the universal eating monitor. You can have a plate, and under the plate, there's a scale. And as a person eats the food, the weight goes down, and you can get the velocity of eating and the amount eaten. And I built one of these. And what we found was that when you put the spices on, people ate them faster, they liked them better, and there have been a lot of studies on this. I think our friend John Peters at Colorado has done studies on this and shown that you've done those with him. The great studies on when you add spices in, you can lower the sugar, you could lower the fat, and they're just as delectable. So my suggestions are to use spices and herbs. And we just did a study on cinnamon, where we showed that cinnamon reduced blood sugar, which helps with diabetes, which there's this common theme with diabetes and cancer. So a lot of interesting things that we could do.

James Hill:

But, Dave, I see now that you mentioned before the ultra-processed foods. So now there's whether you like that term or not, the idea is I think people are realizing maybe we need to get back to whole foods. And if we eat whole foods, and again, that's not to say you never eat some of these processed foods, but a diet that's based on whole foods is going to give you some of those cancer-fighting things better.

David Heber:

Oh, absolutely. You know, I think that people, you know, I had an idea when I worked with one of the big fruit and vegetable companies, you might remember, in the early 2000s. And I suggested to them that they organize the produce section by color because my seven color groups are not random. They're based on science. And they wouldn't do it because they want the red fruits next to the green stuff to make the green look better. So the next time you go to the meat counter, you'll notice some green plastic brass line stuff next to the steak. and it makes it look red. So they use color, not only to market fruits and vegetables, but also packaged goods. You don't have to be real smart to figure out which aisles to avoid. I used to have what I call my trigger foods. I mean, you know, you can go down the chip aisle and you see all the calories. And then they worked with one company that had the fun foods, the better for you foods and the good for you.

James Hill:

Oh yeah. I do remember that.

Holly Wyatt:

So I want to push back against one thing because I've been thinking about this. We just wrote a book. And so, and this has kind of come out in that book. I agree. Seasoning, I believe that helps you eat. And I think variety. So one thing I do is I buy frozen vegetables, but I like it when there's five different vegetables in one pack or the salads that are already chopped up that have the Brussels sprouts and the kale, plus the cabbage, plus the carrots. I can get a bunch and a variety in one setting and we need that, but I still think it's hard to get everything in. So are there any supplements? Are there any ways that you can add, not exclusively, that's like just take a pill or just take a supplement, but in addition to eating well, to get us to that level that we really need to be at.

David Heber:

Well, that actually is a wonderful thing that you brought up, and I'm happy to hear it because there's usually, there's often an antagonism between nutrition and supplements, and there shouldn't be. You know, everybody accepts that a multivitamin, multimineral is important. Andthere's science on many of these supplements. So my approach to this is, first of all, make it easier to get the seven servings of fruits and vegetable in every day. So I start with my red-purple group in the morning, and I take frozen berries and put them into my protein shake, which also has soy in it. So I get some soy and some whey, and I get the right amino acids to help with my appetite. Then at lunch, I'll have a salad along with whatever my entree is, my lean protein entree. And then with dinner, I'll have some steamed vegetables, different colors, like whether it's carrots, tomatoes, or mixed vegetables. Make it easy for people. And then throw some spices on. But in addition to that, I can take some supplements. I can take a turmeric capsule with two grams of turmeric in it, a lot of data on that. I figure, look, it's as if I was living in a jungle and I found a little nice tree and I thought, hey, that would be pretty good fruit to eat. And then my body would take care of getting rid of it. So there's very little toxicity in these supplements. And we're always told about how toxic supplements are. I had the first dietary supplement research center in the United States in 1998 or 99 which was a botanical center. And we did a lot of research on various supplements. So supplements are safe as long as you have some common sense guidance. Always tell your physician about it. But the whole area of drug supplement interactions in my view has been overblown.

Holly Wyatt:

So what about these reds and greens, right? You can now get your greens in a powder. You get the reds and the greens. And I mean, those are hot right now. What do you think about that? Maybe you're getting four servings or five servings of vegetables, but could that get you to seven?

David Heber:

Yeah, but you're not getting all the parts.

Holly Wyatt:

Right. So you're getting some from your food and you're just supplementing. You're not trying to get it all from there.

David Heber:

Well, if you're getting dehydrated broccoli stems mostly and you're not getting there. So the thing is they have to have the key phytonutrients in there. So you need to look, just like with the amino acids and protein, you look for what's the right amino acids. Well, with fruits and vegetables, what are the phytonutrients? So if you're talking about the red group, got to have lycopene. Green group, you got to have lutein. And we know that just 10 milligrams of lutein can help prevent age-related macular degeneration. So there's a benefit to obesity of just eating more fruits and vegetables because they're high in water, low in calories. So the typical 100-gram serving of a fruit is 70 calories. Vegetable would be 50 calories. So you can have those seven servings for only 500 calories and have a variety of them. And it's mostly a lot of water, too. Adam Drewnowski likes to talk about how much water there is in fruits and vegetables. So I think that that's an easy way to get them all in. Supplements is an opportunity to learn about nutrition. So you're going to take things, look into it, you know. Read carefully everything you can find on nutrition and don't fall for all these scams that are out there.

James Hill:

Holly, I want to change directions just a little bit. Dave, I've been really, really looking forward to asking you this question. A lot of our listeners are trying to manage their weight. And as you know, the big thing out there right now are these new incretin-based medications that produce a lot of weight loss and they produce a lot of weight loss regardless of what you eat. My question for you is, how do we think differently about nutrition in the era of these potent weight loss medications?

David Heber:

Well, I think we have to put them in the proper place, number one. They are very valuable for people who have type 2 diabetes and obesity.

They do help control blood sugar better than most of what we had in the past, and they were actually discovered by accident. Donna Ryan told me just the highest dose, and they got a little bit of weight loss. But hitting the system, it's like hitting it with a sledgehammer, because these GLP-1 agonist cause the stomach to slow down. You have nausea and vomiting. There are other side effects that can occur. And so I look at a more natural way to do it if possible, and use that similar to surgery as a later approach. So if you have medically serious obesity, as we've done over the years, you and I have worked on everyone that came down the pike from the 1990s, you know, andthis is a whole new class. We're getting more weight loss. But the real-world analysis that was done recently showed that most people use these for about a year. Then they stop taking them. And their weight loss may be 6%, 7%. At UCLA, we're seeing about 5% on average weight loss with these things. So not everybody loses weight because obesity is such a multifactorial thing. A lot of people eat when they're not hungry. So although this gets rid of some of the craving or people report the food noise went down, whatever... That's not uniform. And so people do have different metabolism and so forth. So I think that this doesn't put us out of business. Nutrition is going to be here for a long time.

James Hill:

I think it's true. I think it's actually a wonderful new tool that illustrates the importance of nutrition even better. And, Dave, we're finding a lot of people that are taking these meds are actually nutrient deficient. So we worried about overnutrition. Now we have to worry about people getting adequate nutrition.

David Heber:

Big point about that. What we're finding is that people tend to lose their taste for, they don't have time, they don't eat as much. So they have a hard time getting the food in. They have to be more efficient, especially in getting their protein requirement. You know, to me, protein is the number one nutrient because if you don't get enough protein, you lose muscle. And when you lose muscle, your metabolism goes down and you increase your fat intake. So, in my What Color Is Your Diet book was all about seven colors but appendix one was how do you estimate how much protein you need. And I would measure the lean body mass and one gram per pound of lean body mass. Now some people do it different ways. They say one gram per pound of the weight you'd like to be. That's okay, too. This is all approximate. But I know that a high protein meal of 20 to 30 grams eaten three four times a day will control your hunger. It won't take care of some of the behavioral stuff. We have psychologists working with us and all of that. And exercise is still extremely important to help build muscle. And so our big thing now in the GLP-1 users is how can we retain their muscle mass as they're losing weight or how can we build it back? And now there are three or four drug companies, of course, that are looking at making a drug that not only has GLP-1 to have you lose weight, they got another substance in there to help you build muscle. So we'll see how that works out.

James Hill:

I worry a little bit when you start getting three and four and five combination drugs, but we'll see what happens.

David Heber:

Right. Exactly. But I think we know what to do. And I think that everything we're talking about in terms of natural nutrition will activate GLP-1. Not only they're incretin drugs, but there are some supplements now that are claiming to stimulate GLP-1. And we know protein and calcium stimulate GLP-1, and flavonoids, which are one of the phytonutrients from fruits and vegetables, stimulate GLP-1. So what is GLP-1? It's really part of a network of gut hormones that help you control the rise in blood sugar after you've eaten a meal, and they help to end a meal. So if you make that super strong, you find out your meal ends before you get a lot of nutrition in. So I think the thing you want to do is cut down on your portions. All the things we've told people and you've been a champion of small changes. I think those are often more sustainable. At least do something, you know. Stop eating after seven o'clock. Split an entree with your wife when you go to a restaurant, you know, things that you can do to cut your total caloric intake while maintaining the nutrition.

Holly Wyatt:

I want to switch to one topic that's really hot right now, too, that I think people are asking a lot of questions. So, some new studies, we just had Dr. Vicky Catenacci on, talking about the 4:3 fasting. We've had some other people talking about intermittent fasting. The role between fasting and cancer, you know, there's been a lot of talk about that. Is that a good thing? Is fasting good for cancer? We have some data about weight loss that's just been published, but what about cancer? What do you think about that?

David Heber:

Well, it's very interesting. So there's a fellow named Valter Longo across the city at USC, not UCLA, but USC, and I have a joint appointment in their aging department over there, but he has been a champion of fasting. And he had cancer patients fast before they got chemotherapy. And then that reduced some of the side effects because what it did was it dampened the immune system. When you fast, not only you produce ketones, but you dampen your immune function. And then he came up with what's called the fasting mimicking diet in animal studies, and he came up with a fasting mimicking company that produced supplements that basically it's a carbohydrate-restricted, high-fat, low-protein diet. And we've been arguing about protein for many, many years. And he finally said, "Well, if it's an older person, then they do need more protein."

But he was looking at NHANES data. And if you look at just U.S. Data, protein basically means a steakhouse. And so that could have negative effects. But I think that people don't get enough protein at the right times. And a typical woman that I deal with would have to get 75 grams of protein a day. Her husband would need 125 to 150 grams of protein a day. That's a lot of protein when the RDA is, what is it? For a woman, it's 50 grams. And for a man, it's 0.8 times 7, 56 grams for a man and a little less for a woman. And it makes no sense. It's all arbitrary based on 1973 data in medical students eating egg whites. So we've got to update our nutrient requirements. And protein is number one. You can make fat and carbohydrate. If you look at intermittent fasting, I think the big benefit is you stop eating after 7 o'clock. A lot of people eat 600 to 700 calories sitting in front of the TV, stressing out at night after work. And so if you tell people they've got an eating window of 12 hours that they don't need to eat, say, from 7 p.m. To 7 a.m., I don't think that's so bad. And you can still get all your food in during the day.

James Hill:

I agree. I think that's a more reasonable approach.

David Heber:

Absolutely. I mean, to make everybody, oh, you've only got six hours to get your food and get busy. I think that's too much. And just like the keto diet, I don't think people do it.

Holly Wyatt:

I don't know. We're having some success with it. And I think the way we've been doing the 4-3 is not to eat during the day and then to have one meal in the evening. I like some of the data that shows, like what you said, is it impacting inflammation? And you just talked about how inflammation may be a really important player when it comes to cancer risk. So is it important for there to be times when your body kind of pushes DAC down against that inflammation, especially because we know obesity, you kind of have that low-grade inflammation that's there all the time, which is different than the inflammation you get when you're, immune response. So I don't know. I think it's an interesting way of thinking how it may impact some of the mechanisms that we think might be causing cancer and obesity.

David Heber:

Well, I'm a huge fan of what I call chrononutrition, that is having a 24-hour rhythm of nutrition. And this gets us to the issue of sleep and obesity. And I think sleep is when you really get an anti-inflammatory effect. And I follow my sleep actually with my smartwatch. And I look for my heart rate, and you have the Oura ring, I look for my heart rate to go down after I really get the sleep. So I'll be knocking around, trying to get the pillow right and all that stuff. And then eventually it'll slow down. And then I wake up and I'm a lot more energetic when I've had that seven hours of sleep. And I used to be one of the real limited sleepers and king of the red-eye flight, Jim will tell you.

James Hill:

I remember that, Dave.

David Heber:

I mean, I would be showing up with four hours of sleep. How did you do that, Dave? And I thought I was so smart and I wasn't. It was really dumb.

David Heber:

And so now, like last night, I slept seven hours and 15 minutes. So I time myself and I make sure I get that rest. And automatically you're sleeping, you're not eating, hopefully.

James Hill:

Yeah, no, that's really important. And Holly would never forgive me if I don't bring up the thing I'm always supposed to bring up, which is physical activity.

David Heber:

Oh, absolutely. So I have now, I built, whenever I had a little extra money, I bought gym equipment. So I've got a fully supplied gym in my retreat upstairs. And this morning I was doing exercises, you know, and I do both cable machines for weight and I have some various, I have a leg press and various things I do. And I don't do a treadmill anymore. I got a sedentary bicycle, which I recommend for older folks like me, because there's less stress on the lower back and the neck and the knees and everything else that's aching. And getting the muscles in shape is tremendous. There's a lot of studies that show that physical exercise, 150 minutes a week of moderate exercise will change your mitochondrial metabolism.

James Hill:

See, Dave, that's the key. People talk about exercise and burning calories. Exercise optimizes your metabolism. It's working for you during those times you're not exercising.

David Heber:

A hundred percent. I mean, there's a thing called mitophagy, where your cells get rid of abnormal aged mitochondria. We have a fellow who studies mitochondria, and when they age, they stop working right. And a couple of studies show that with exercise, moderate, like I talked about, your muscle mitochondria in your heart and in your skeletal muscles will get healthier, be more efficient in burning calories. So a lot of these supplements you read about in popular books are supposed to go right down to your mitochondria and change everything. Physical activity can do that. And it's free. It's easy to do.

James Hill:

I love it. I love it, Holly. He's talking my language.

David Heber:

There you go.

James Hill:

All right, Holly, it may be time for some listener questions.

Holly Wyatt:

Yeah, I want to do it because we have three good questions. I want to make sure we get to all three. So I'll take the first one. Is there any evidence that weight loss later in life reduces cancer risk? Because, you know, we have some mixed messages about obesity and overweight as you get older. What is that about cancer? Is there evidence that weight loss will help you even when you're in the later stages of your life?

David Heber:

Well, we have to emphasize, we haven't talked about this, aging is one of the major risks factors for cancer. So whenever you look at cancer statistics, it's the age-adjusted rate of a particular cancer. Because all cancers go up with aging. And many of the changes in aging in the genome are similar to what goes on with cancer. So aging, you know, also big effect on type 2 diabetes, etc. So 90% of the people who get obesity-associated cancers occur after the age of 50. So a lot of the younger cancers are more aggressive cancers we hear about, like the estrogen receptor negative breast cancer or the very aggressive prostate cancer in younger men. The later cancers, the slow-growing cancers, many of them are obesity-associated. So it's really important to control your obesity at any age. And I talk about health span and how you feel every day. And if you do things reasonably, you can liberate yourself from a lot of the brain games, the semi-addictive nature of these foods, these ultra-processed foods they talked about, and I don't like the term either, it's too indicated. But there are studies showing that, and some people argue with the studies, but they show that people are really attracted to these things because they're so designed for taste that you can't just eat one, right? That's what they used to say, you can't eat just one chip, you know? And they use them as stress reducers. I can admit I used to be addicted to chili cheese corn chips and I would buy the little package and wait till they went on sale. And I got my patients who are binge eaters to do air pop popcorn and they were so desperate for the taste they would spray them with mustard and water. People basically love to eat. It's a stress reducer and you have to deal with that. With a older age, you have to actively work against the disintegration of your body. You've got to exercise.

James Hill:

That's right.

David Heber:

You've got to eat right.

James Hill:

You're not going to win, but you fight the good fight.

David Heber:

Fight the good fight, you know, and rage against the night.

James Hill:

All right. I've got another one here that's a good one. Are plant-based diets better for cancer prevention than other diets?

David Heber:

When I say plant-based, in general, you know, the different institutes of NIH had different missions. For instance, NIDDK was all about sugar and so forth, and we kind of got them into obesity in the later years, as you'll remember. But NCI was always about fruits and vegetables and the colorful phytonutrients fighting cancer. So, a plant-based diet if you do it right, is correct in terms of being the maximum way to suppress cancer, to cause cancer prevention. But you have to have enough protein to control your hunger so that you don't get obese. I indicated how you can get the colorful fruits and vegetables and spices and herbs into your diet for very few calories, adequate protein. And I still believe in cutting down on excess fat. I mean, I know the low-fat diet is criticized, you know, but if you do low-fat with a snack well cracker, that's different, okay? I think it's control the fat and control the sugar. It's both fat and sugar. And if you look at places that depend on high levels of sales, whether it's fast foods that represent maybe 30 percent of food intake in America and you look at what's the breakdown of those things, it's high fat, high sugar, high salt. And salt covers all of the bad off tastes of old hot dogs and hamburgers so...

Holly Wyatt:

I’m going to add one more in here because this goes with the next question. How does alcohol fit into this picture? Is there a compounding effect with weight and cancer and alcohol.

David Heber:

Absolutely. I mean, alcohol at different levels, but, you know, first of all, there are calories associated with alcohol and alcohol reduces your inhibitions. So if you have a drink and you see some buffet or something, you're going to, and I was on a cruise ship with my kids recently to Alaska and people walking around because it's free alcohol and food and they're all overeating. So I think there's a real connection. Now, there was a preventive benefit based on some studies in France of cardiovascular disease with resveratrol and red wine. And then recently there was a study where they said even one glass of wine in a woman could increase breast cancer. Well, I think that's an overuse of epidemiology. What they did was just extend the line. So if you have four to six drinks, definitely there's an effect. If you extend the line back down to one drink, you can find a statistically significant effect. But I'm not sure I believe in that. I think if you're going to have one or two drinks, but be very aware. I'm very conflicted about recommending any alcohol because they're looking at something that causes a huge amount of disease and problems in America. And there are a lot of people who are genetically addicted to alcohol.

Holly Wyatt:

But is it the alcohol, is alcohol going through weight? You talked about how if you have alcohol, you're more likely to eat more, overeat, dah, dah, dah. Or is there an independent effect of alcohol and cancer?

David Heber:

There have been a lot of studies on alcohol and breast cancer, for example, but it's always hard for me to isolate that because there were nurses' health studies. And I can tell you, most of those nurses that had three glasses of wine were also obese. It's hard to separate it from the whole diet. That's the problem with nutritional epidemiology. It's not infectious disease. You can't find, oh, it was the snackwell or it was this, it was that. No, you can't do it that way. It's an integrated process.

Holly Wyatt:

Got it.

James Hill:

All right, Dave. You're a clinician as well as a researcher. You're an MD. You see patients and you've done research. Can you think of a patient or a patient story that kind of changed how you think about the science?

David Heber:

Yeah, I think there have been a number of them that I've worked with. And I think the type of patient that really got to me is prostate cancer patients, where in fact, they could come in with a Gleason 9 and metastatic disease and undergo the standard treatment, and then they're alive 25 years later because they took on a healthy diet and lifestyle.

James Hill:

Wow, that's powerful.

David Heber:

It is. And there are a lot of them. For some reason, and it may be genetic, a lot of the prostate cancer patients are captains of industry they tend to be kind of aggressive kind of guys and they take on this, you know. Because I dealt for a long time in a breast cancer clinic and it's going to sound very sexist now so I apologize. But the relationship of men to nutrition is a little different than with women are much more emotional about food and men, just tell me how big it is how much where do you want me to cut the lumber and I'll just go ahead and eat that diet. And i get these guys and they totally go with it. They don't have any problem with it. And then the weight comes down and they get together and they get group support and they do really well. So we've done a lot of studies on prostate cancer with very successful adherence. And now they've shown that obesity not only increases the rate of growth of the prostate cancer, but also your survivability from it. And we did the Women's Health Initiative in Women and the Women's Intervention Nutrition Study with late Dr. George Blackburn.

David Heber:

And we showed, it was interesting stuff, because I had read a lot about breast cancer was supposed to be about estrogen. And it turned out it actually had a lot to do with insulin. It turned out the insulin drop was more important. So again, we see kind of an overlap with obesity, type 2 diabetes, which I call diabetes obesity. And I really want to get to these things earlier before they become diagnosed. So we need to talk about pre-diabetes, pre-hypertension, pre-heart disease, and pre-cancer. And we have great ways of screening for cancer nowadays. And that should include screening and not just waiting for the diagnosis, but screening. And you've got some risk factors, get on the diet and lifestyle and physical activity that you need to have.

Holly Wyatt:

Love it. All right. So one of the things Jim and I talk about is how, even though we have a lot of experts on the field, you know, science is always evolving and we get things wrong. Some of the things we think are right probably aren't right. So I like this next question that there's a vulnerability question. What's something that maybe you got wrong, you thought was true, and then you realized after some time passed, some science happened, you studied it or other people studied it that, oh, mate, I kind of, that was kind of not the right idea. We have evolved maybe and changed our way of thinking.

David Heber:

You know, it's interesting. I've always been what they call bleeding edge, not leading edge.

James Hill:

This is true. This is so true of this guy.

David Heber:

I have kind of the opposite problem. I'm right before everybody else. That's my problem, you know, because I come up with these things like protein in 2010, you know, and the phytonutrient. Well, actually in 2001 with the protein, but, you know. And then the fruits and vegetables in 2001, everybody thought I was crazy. And when I came to UCLA in 1983, I remember I met with the director of the medical center and, well, we know about obesity and heart disease and that, but what is this thing with breast cancer? We never heard of that. What are you talking about? And so I had a hard time breaking into the clinics with these ideas.

So, you know, I would say what revolutionized nutrition was the discovery of the role of the microbiome. And so about 10, 15 years ago, I met a 92-year-old professor who happened to have an anaerobic lab at UCLA, and we started collaborating. His name was Sid Feingold. He was 98 when he died. And he and I did some research studies on the microbiome, immune function, and I think immunotherapy and the microbiome and diet and exercise and also daily rhythms of the microbiome. The microbiome is where a lot of the action is because there are a million genes in the microbiome, only 23,000 genes in the human. And you can now measure which ones are turned on by doing transcriptomics and then metabolomics. I have some other friends like Sean Adams do a lot of metabolomics and transcriptomics. And I wrote a textbook on precision nutrition recently, which talks about how these advanced computers are going to allow us to integrate all of these different inputs and finally understand personalized nutrition. And it's going to have an effect on aging.

James Hill:

That's actually very exciting. All right. Well, we're coming to the end here. I want to take a minute and sum up what we've talked about, that there is a strong link between obesity and cancers, many different forms of cancers. Weight loss is something you can do to reduce your chances of obesity, but you can also do things with lifestyle. Americans get, well, worldwide, people get far too few fruits and vegetables, and we've got to increase fruits and vegetables. And there's a variety of ways that may help. Sleep is important. Physical activity is important. So there are lots of things you can do. And it's never too late to make lifestyle changes, weight changes, and reduce your chances of getting cancer. Dave, it's been a real pleasure. Seriously, listeners, this guy is a giant in our field. He has been a leader for so many years, so many innovative approaches, and it's great to see you still with the excitement and the energy about what you do.

David Heber:

Well, right back at you. And thank you for those comments, Jim. But, you know, Jim has been such a leader, a president of so many societies. And, you know, it takes lots of different skills and a village to move this nutrition stuff ahead. And, Jim, you bring so many unique skills to this. And I think, Holly, you're a fantastic addition to Jim's team and have been for a number of years. And so I think between the two of you, spread the word. And hopefully we'll get more people healthy, less people overweight, and lower the risk of all these chronic diseases that they're talking about now at the government level. It's going to take more than removing the food coloring. It's going to take getting real food colors in there.

James Hill:

Absolutely. Listeners, we want to hear from you. We want your questions, your comments. Holly, how did they contact us?

Holly Wyatt:

They can go to [weightlossand.com](http://weightlossand.com/), and there they can see all the episodes that we've done, but also can send us questions there.

James Hill:

Let us hear from you, and we'll see everybody next time on Weight Loss And.

Holly Wyatt:

Bye, everybody.

James Hill:

And that's a wrap for today's episode of Weight Loss And. We hope you enjoy diving into the world of weight loss with us.

Holly Wyatt:

If you want to stay connected and continue exploring the “Ands” of weight loss, be sure to follow our podcast on your favorite platform.

James Hill:

We'd also love to hear from you. Share your thoughts, questions, or topic suggestions by reaching out at [weightlossand.com](http://weightlossand.com/). Your feedback helps us tailor future episodes to your needs.

Holly Wyatt:

And remember, the journey doesn't end here. Keep applying the knowledge and strategies you've learned and embrace the power of the “And” in your own weight loss journey.