[music]

Brian Lehrer: Brian Lehrer on WNYC and we all know how important it is to eat well but where we struggle is actually knowing how to eat well. Education on nutrition is confusing. There are all sorts of seemingly contradictory pieces of advice, diet plans that verge on disordered eating, and pervasive myths about what foods are good and what to avoid. Now we conclude our week-long series on dispelling some of those nutritional myths that have permeated American culture.

We've been tackling two myths a day with Sophie Egan, author of How to Be a Conscious Eater: Making Food Choices That Are Good for You, Others, and the Planet. She's a New York Times contributor. She recently penned the article that inspired the series called 10 Nutrition Myths Experts Wish Would Die. We've been going down the 10 all week to a day and so we're up to number 9 and number 10.

Also joining us today, because she's quoted in this part of the article, is Marion Nestle, Professor Emerita of Nutrition, Food Studies, and Public Health at NYU. Guest on this show many times, and the author of many books, including her latest, Slow Cooked: An Unexpected Life in Food Politics. Sophie and Dr. Nestle, welcome back to WNYC.

Marion Nestle: Oh, glad to be here again.

Sophie Egan: Thank you. Likewise.

Brian Lehrer: Sophie, soy products and the link with breast cancer. This one is pervasive. What's the myth? What did nutrition experts tell you?

Sophie Egan: The myth is that eating soy-based foods can increase the risk of breast cancer. I spoke with Dr. Frank Hu, a Professor and Chair of the Department of Nutrition at the Harvard T.H. Chan School of Public Health. He has really studied this very closely, and he wanted to set the record straight by saying that although high doses of plant estrogens in soy which are called isoflavones have been found to stimulate breast tumor cell growth in animal studies, that relationship has not actually been substantiated in human studies. So far the science does not indicate a link between soy intake and breast cancer risk in humans.

Brian Lehrer: You're right, consuming soy-based foods and drinks like tofu, tempeh, edamame, miso, and soy milk may even have a protective effect toward breast cancer risk and survival. Really the opposite is true. What does the research say?

Sophie Egan: The research shows that there's such a tremendous array of beneficial nutrients in soy foods like those that you mentioned. High-quality protein, fiber, vitamins, minerals that they actually can be related to reduced heart disease risk. Ultimately the research really underscores that you should feel confident incorporating soy foods into your diet because of those really beneficial nutrients and because of that lack of a link between soy intake and breast cancer risk in humans.

Brian Lehrer: Dr. Nestle, you are here because you were quoted on the next myth that we'll get to, but do you want to weigh in here on soy products and the link to breast cancer?

Marion Nestle: Sure. I think whenever you have a situation in nutrition where some research shows that something's harmful and some research shows that something's good for you, it's probably just a food, and you should eat it like every other food in moderation and mix it in with everything else you're eating. I don't worry about soy products at all.

Brian Lehrer: It seems there are articles every couple of months linking certain foods to cancer. Grilled meats was somewhat recently a headline in The New York Times. This show recently covered the link between alcohol and cancer. This will get to your next myth in a minute but cancer is scary and sometimes it seems everything causes it if you collate enough numbers, where it seems like everything gives you cancer to quote an old Joe Jackson song. Where can people get the best information on what to avoid, Sophie?

Sophie Egan: I'm guilty of having written several of those articles that you're referring to. Not the one on alcohol but definitely on processed meats and grilling and so forth. I would refer people to the American Cancer Society, the World Cancer Research Fund, World Health Organization, and the American Institute of Cancer Research. Those really are go-to reference points and hopefully will help allay concerns that "everything causes cancer" which is certainly not my message and it's certainly not what I believe the research shows.

Those are great places to find out what is the science showing as researchers work really hard to just better understand this very scary and very much-needed area of research to better understand what is contributing to these increased numbers and so forth. It's hopefully a place where you can learn the science but ultimately gain actually some peace of mind by seeing that it's not everything in their diet certainly but that some foods do carry greater risk than others.

Brian Lehrer: All right. [crosstalk]

Marion Nestle: If I can throw in something on that-

Brian Lehrer: Yes, please.

Marion Nestle: -I'll just point out that this research is extremely difficult to do and that anytime you try to look at a single food in the diets of people who consume-- we consume hundreds of foods and our diets change from day to day. This is very, very challenging research to do and nobody should underestimate the difficulty.

Brian Lehrer: That brings us to myth number 10 in this 10 Nutrition Myths Experts Wish Would Die article by Sophie Egan in The New York Times. Myth number 10, fundamental nutrition advice keeps changing a lot. Dr. Nestle, you told Sophie for this article that some fundamental guidance has stayed the same since the 1950s. Want to point out some of that?

Marion Nestle: I sure do. It depends on whether the world divides into lumbers and splitters, and I'm a lumber. I look at the big picture rather than individual nutrients or even individual foods. From that big picture in the 1950s, Ancel Keys and his colleagues came out with dietary advice for chronic disease prevention that said you shouldn't eat foods with a lot of salt, sugar, and saturated fat. You should eat a lot of fruits and vegetables. You shouldn't gain weight if you could avoid it and don't drink too much alcohol.

That advice looks like it came out of the 2025 dietary guidelines for Americans. It really hasn't changed at all except that the dietary guidelines took 150 pages to say it. That's where the complication comes in is because they're looking at every single element in it without looking at the big picture. As I'm always fond of quoting Michael Pollan, "Eat food, not too much, mostly plants." That takes care of it.

Brian Lehrer: Yes. Are there some areas of nutrition, though, that have really drastically changed since back then? Some of the myths that Sophie's been busting in this series are being busted because science has progressed.

Marion Nestle: I think science progresses but the basic facts about diet and health have not changed. Eat fruits. Eat a largely, but not exclusively plant-based diet. That's the diet that's been demonstrated to be good for heart disease, cancer, gaining weight, all of those things. You want to avoid a lot of junk foods. The details of that, the arguments about fat and sugar, I don't think you-- again, go back to how difficult this science is. It's very difficult to look at a single nutrient or a single food if you take it out of the context of the total diet and the total calories and everything else that you're eating. If you look at the big picture on this, "Eat food, not too much, mostly plants," really works.

Brian Lehrer: Sophie, why did you choose to end with this myth?

Sophie Egan: Yes. Definitely was intentional. It's really to try to help readers end the story with the sense that this is not a case of nutritional whiplash which I think is a common perception, and I totally understand why that happens through one of the things we talked about earlier in the show which is this game of telephone that often perpetuates misinformation or even intentional disinformation. Instead, it's to say that yes, the science does evolve and some of the details there is some nuance, some refinement, let's say from all fat to type of fat. That was one example, or in the case of allergy research where the type of study is actually showing a different conclusion.

There's certainly better and different types of information that come out that may, again, on a more nuanced level but just as Dr. Nestle said, it's not dramatically shifting in the big picture, and that hopefully readers and eaters, for that matter, can really try as much as possible to keep their focus on that big picture.

Brian Lehrer: Dr. Nestle, before you joined NYU I know you were a senior nutrition policy advisor in the Department of Health and Human Services, federal government, and editor of the 1988 Surgeon General's report on nutrition and health. Do you want to talk a bit as we end the series about what the role of government is or should be when it comes to nutrition education?

Marion Nestle: I was on the Dietary Guidelines Advisory Committee in 1995 and it was explained to us at the time that the public is confused about what to eat and we ought to be giving the public the best advice that we possibly can based on the available research. I think that's government's role. We want a healthier population. Everybody eats, everybody is confused about what to eat, and I think the confusion comes a lot from the marketing issues because nutrition research is so much fun, that research on individual nutrients and individual foods is really fun to read about it, even though a lot of it is industry-sponsored and has a marketing purpose and it's government's role to sort through all that.

I wish the government did a better job. The original Dietary Guidelines for Americans had four-word advice, eat less sugar. That's still good advice, and because that advice really is unchanging, it was hard fat, saturated fat, salt, sugar, way, way back in the 1950s. That's 70 years ago and we're still talking about exactly the same things. It's just hard for people to eat that way in a food environment in which food is pushed at you all the time and a lot of it is what we're now calling ultra-processed, which are foods that are formulated to be irresistibly delicious, and that nobody can stop eating, and that's really where the problem is. Is that--

Brian Lehrer: Go ahead, finish your thought, I'm sorry.

Marion Nestle: We love eating, food is wonderful, it's one of life's greatest pleasures and joy.

Brian Lehrer: I've got to eat less sugar question for you that might be on a lot of listeners' minds because of press coverage this week. Just this Monday, there was a study published in the journal Nature Medicine, in which researchers found links between a popular zero-calorie sugar substitute, Erythritol, and increased risk of heart attack and stroke because of blood clotting, and Dr. Nestle, you are quoted in the New York Times piece about it as basically saying, "Don't sweat it". Since this is getting a lot of press right now, want to say very briefly why?

Marion Nestle: I don't think I said don't sweat it. [crosstalk] I think the study was pretty impressive and I'm not in favor of artificial sweeteners, they're chemicals, and we don't know how they're metabolized. I think it's not going to kill you on the spot, but maybe it's something that you don't want to eat them. I don't need artificial sweeteners if I can avoid them, even though they're not going to kill you on the spot. Again, the research is very difficult.

Brian Lehrer: Yes. When studies like this one come out, how do you make your first assessment as to whether it's serious? Is there any scientific study literacy you can pass along to our listeners for when they read the lay press?

Marion Nestle: Absolutely. When I read this study, I was impressed that they had gone to a lot of trouble to try to figure out what the mechanism was, and that's what I found most impressive about the study was the idea that it makes platelets clot. I have a few rules about food. If it's not ingredients that are really present in regular food, I try to avoid them. As for evaluating scientific studies, if it's a breakthrough, don't do it, it doesn't mean anything.

If it tells you everything you knew about nutrition is wrong, no, you want to be cautious about that. You want to make sure that the studies were independently funded if that's possible to find out, and do they make sense? I think this is a situation where common sense is really useful. If it's something that suggests a diet where you eat more fruits and vegetables and don't eat a lot of junk food, that's probably good advice.

Brian Lehrer: A listener is asking, what about eggs? Doesn't the advice on that go back and forth?

Marion Nestle: It does, except that it's still talking about the same amount of cholesterol in the same amount. Here's a perfect example, the advice about eggs right from the beginning was one a day is just fine, and that advice is still being given. With all of the other arguments about it, you have to look at this very, very carefully.

Brian Lehrer: Sophie, we've had you on all week to talk about some of the myths that really frustrate nutritionists. That New York Times article looks like from the comments on it and the amount of time they've emailed it out, I think you've had a lot of readers of that article, and I think you've had a lot of listeners appreciating it this week as you've walked through the 10 myths that you identified with us. Why do you think, as a final question, that certain myths have such longevity, and what do you think can be done to continue to bust them?

Sophie Egan: This is a great question, and there are several factors, I think, at play. One of them really relates to the broader issue of fake news false information, which is more human nature. We respond to things that are novel and there's really interesting research that shows how much more likely we are to click on an article or to share an article or post to social media posts for something that's really contrary to what we believe.

Just as Dr. Nestle said, you really want to be mindful, and yet the intuition is counter to this when you see something that tells you everything you thought about X is wrong. Part of this, I think, really stems from just the clickbaitness of some very misguided stories, certainly not those in the New York Times or those that I write, but that is certainly fueling a lot of misunderstanding, frustration, misperception. I've written a lot about how there's also a lot of diet evangelism, and this is where you have really influential and people now whose jobs are as influencers to promote a certain diet and promote certain products. Those are not tied to independently funded research, those are not based in the evidence.

In general, I think when we have that confluence, that human nature, we're vulnerable to this novel information, paired with really often poorly intended, or those with an agenda to sell certain types of products and whatnot, it's a perfect storm. What can be done about it? Certainly, the tips that Dr. Nestle shared, I think, are great. Knowing that there's a huge body of research that's not ever going to either make it in the publication or in the news which is reinforcing what we already know.

I've said this before, you're never going to see an article that says, "Blueberry is still good for you", but we have to, in our minds, imagine that those are all around us all the time reinforcing what we already know. Then the last thing I'll say is that we have to look at who are the trusted voices, who are those messengers of information? In the US, that tends to be registered dieticians and health professionals, doctors. It tends to be chefs, actually, and it tends to be friends and family. The more that you are looking at who you're getting your information from, and where are they getting their information from, and hopefully we can start to, overtime, break this game of telephone link by link.

Brian Lehrer: I want to thank you both, as we have to leave it there. Our special guest for today was Marion Nestle, Professor Emerita of Nutrition, Food Studies, and Public Health at NYU, and the author of many books, including her latest, Slow Cooked: An Unexpected Life in Food Politics. My guest all week has been Sophie Egan, author of How to Be a Conscious Eater: Making Food Choices That Are Good for You, Others, and the Planet, and a New York Times contributor. She penned the article that launched the series, 10 Nutrition Myths Experts Wish Would Die. Marion Nestle, always a pleasure, and, Sophie, thanks for walking down that list of all 10 nutrition myths over the course of this week.

Sophie Egan: Thank you much for having me, it's been a pleasure.

Marion Nestle: Me too.

Copyright © 2023 New York Public Radio. All rights reserved. Visit our website terms of use at www.wnyc.org for further information.

New York Public Radio transcripts are created on a rush deadline, often by contractors. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of New York Public Radio’s programming is the audio record.