The Dr. Hyman Show - Eggs? Why the Headlines Got it All Wrong

Episode Date: March 22, 2019

A new study published in the medical journal JAMA says, ‘Eggs are bad,’ but are they really? In this episode, we take a look at the specifics of the study. This particular study is an observational study; it does not prove cause and effect. An ideal nutritional study would take 10,000 people and have them eat eggs for 20 years, then take another 10,000 people, and for the same time period, keep them from eating eggs to see what happens. Of course, this would be incredibly difficult and very expensive to do. This recent study surveyed 30,000 people over a 17 year time period, with each person completed one questionnaire about what they’ve been eating. During the time this study was conducted, eggs were considered bad. We were told not to eat eggs; to avoid cholesterol. So people who were eating eggs were likely people who weren’t otherwise health conscious. It doesn’t mean the eggs caused the heart disease.

Hi, I'm Dr. Mark Hyman, and today my team and I are excited to share with you a special mini episode of The Doctor's Pharmacy. Hey, everybody. Guess what? I'm going to talk about eggs. Why? Well, I just got off the trail from a backcountry ski trip with my daughter and her boyfriend and his mom, and I saw the headlines that you all did, that eggs are going to kill you.

Don't eat eggs. They are bad for you. In fact, if you eat eggs every week, you're going to increase your risk of death significantly by 17 or 18%. Now, is this true or not? Now, are these going to kill you? Are these evil?

Are these going to be the death of you? Well, I don't think so. And here's why. The problem with the headlines is they don't actually represent what really is going on in the science. And it makes me crazy because the science is there, but the interpretation of the science is not clear. When you look at the headlines, they take the headlines and say, hey, eggs are going to kill you, so don't eat eggs. Oh,

we got all this wrong. Well, the truth is that you have to look at the details of the study. And I want to go through a little bit of a science conversation today because most people don't really understand how to look at the research. For me, I didn't either when I was graduating from medical school. So when you look at studies, you have to make sense of what they say and what they don't say. First of all, how was this study done? Well, they took six different studies. They smashed them together. It's called the meta-analysis, which can be done, but it looks at populations over time. Now, these types of studies are called epidemiologic studies or population studies or observational

studies. They literally observe people over many decades and find out what happens to them. And if there's a correlation between something you're doing and some disease, right? So smoking and for example, cancer, they did an epidemiologic study and they found that yes, people who smoked got more cancer. And the amount of increase in the risk was 20-fold, like literally 2,000%

more. That's a lot of risk increase, right? So when you look at this study, it mapped about 30,000 people over 30 years. Different studies were different time periods. And when they looked at the studies, they found that they took one questionnaire, one food frequency questionnaire over a period of 30 years, depending on the study. And then they said, well, gee, these people who we asked what they ate last month or last week or last year, we hope they remember. Now, do you remember what you had last Thursday for lunch or last Wednesday for dinner? I certainly don't. And it's very hard because people's diets change over time.

We're going to talk about the problem with this. So the first problem is this food frequency questionnaire is the base of the study. And this is fundamentally flawed, and I'll talk about that in a minute. Then they looked at what the increase was in the risk of heart disease in the people who reported that they ate eggs. Now, there was a very small increase, okay? We're talking about basically a 6% increase over everybody else for death if you ate, I think, three eggs or more a week, and I think maybe an 8% increase in death. People who ate a lot of eggs, the highest group, had a 17% increase in heart disease and a 18% increase in death from all causes. Now, what does that mean? That means it's a 0.18 increase or 0.17

increase or 0.06 increase compared to a 20-fold increase. If it's anything less than a two-fold increase, in other words, a 100% increase, it's pretty meaningless. And it only shows correlation. So this study does not prove cause and effect. There's no way that you can make a conclusion that eating eggs causes heart disease from this study. All you can say is that people during that time period who they asked one questionnaire

seem to have more heart disease over the long period of time. It doesn't mean the eggs cause a heart disease, right? Because during the time that people did the study, eggs were considered bad. We were told to not eat eggs, to avoid cholesterol. So the people who ate eggs may have had other things going on in their life that made them at higher risk. What? Maybe they were smokers. Maybe they didn't eat so well. Maybe they didn't care about their diet. Maybe they didn't take their supplements. Maybe they didn't eat fruits and vegetables. Maybe they were smokers. Maybe they didn't eat so well. Maybe they didn't care about their diet. Maybe they didn't take their supplements. Maybe they didn't eat fruits and vegetables. Maybe they had all these bad habits, including eating eggs, because eggs were bad, that led to the heart disease. It may have nothing to do with the eggs. For example,

if I, we looked at this study, for example, a women's health study, where they looked at 100,000 plus women. There's a nurse's health study. So they looked at 100,000 plus women over many years, and it was an observational study. And they found the women who took hormones, like Premarin, seemed to have far less heart disease, like 40% less risk of having a heart attack. And everybody thought, oh, hormones are great. They're going to protect women.

We'll give women all these hormones, and they'll be healthier. Turns out when they did the billion-dollar study, the randomized control study, an experiment, where you literally take half the women and you give them hormones, the other half you don't. You match them up so they're the same. Guess what? That study was completely overturned and found that there was an increased risk of heart attacks and stroke and cancer and all these other problems for women who took the hormones. Overnight, 50 million women stopped taking hormones. Why? Because they did an experiment to see if the hypothesis was right. When you look at this original study, the women who took the hormones were healthier. They went to the doctor. They

cared about their health. They wanted to do everything they could do to prevent any problems, so they didn't actually get benefit from the hormones. In fact, they may have been harmed by them, but because they exercised and didn't smoke and ate well and had all these good habits, they were healthier. It wasn't the fact that they took hormones. In fact, it did kill them. So same thing with this egg study. We can't get distracted and think that just because the headline says this. In fact, it kind of makes me angry because it's shoddy journalism.

We really don't have good journalism where they go, okay, what is the study? What was the design? What does it prove? What does it not prove? It doesn't prove anything. It gives you a hypothesis for testing. The ideal study would be to take 10,000 people who give them eggs and 10,000 people and don't give them eggs for 20 years and see what happens. Well, that's never going to happen. No one's ever going to be able to do that study. So we have to kind of draw on these other ways of thinking about things. The other problem with these studies is the food frequency questionnaire. So a lot of our studies in nutrition, and I just did a lecture on this called

The Failure of Nutrition Science and Policy, where I went into the details of why are nutrition researchers hard. It's hard to do. You can't literally take 10,000 people and give one group eggs and then give another group no eggs and see what happens. It's just a very expensive, hard to do study, and nobody's funding it, right? Drug studies they do and they can use the same design, but it's not easy for nutrition. So they use these food frequency questionnaires, which are really flawed. Why? Because people don't report what they think is bad. If you,

for example, hear that meat is bad or fat is bad or eggs are bad, then you're probably not going to report that on your food frequency questionnaire. People overreport the foods they consider good, like vegetables and fruits, so it may not be accurate. People also don't know all the ingredients they're eating. If they eat on a restaurant, if they eat prepared foods, people don't weigh or measure their portion sizes.

They don't track everything they eat. They're just human. They can't remember everything they eat. People's diets change over long periods of time. So it's really quite a problem. And we see this, you know, when you look at these epidemiologic studies, these observational studies, you know, there's been an analysis of these and whether or not they're actually valid or not. And it turns out that John Ioannidis, who's a scientist from Stanford, has critically looked at all this data.

And he said, you know, we look at sort of the top claims, really great, wonderful studies that have been done, these observational studies. When they actually do experiments to see if the hypothesis that's generated in these observational studies, these correlations, are true, five out of six of them, of the most cited claims, were overturned in a decade. Another review by a guy named Stan Young looked at 52 out of 52 major claims from epidemiology were not validated when they were doing experiments or randomized trials. So they're very problematic. And the headlines that basically say, don't eat eggs, cholesterol is going to kill you, are pretty worthless. And the degree of the effect was so small. You might have heard another study that was recently published. It's the same thing where

the headlines were low carb and high carb diets increase the risk of early death study finds or low carb diets may cut years off life from Newsweek. Well, guess what? That study was, again, an observational study. They relied on these inaccurate food frequency questionnaires. They didn't adjust for all these confounding factors. They focused on the quantity instead of the quality, right? Is a carb a bagel or is it a broccoli? It's very different. And again, they looked at stuff from different sources. So when you look at this original low-carb study, low carbs will kill you, right? Well, there were two food frequency questionnaires they used over 25 years, separated by six years, meaning they just asked people twice over 25 years what they

ate. The average calorie intake reported was 1,500 calories a day. Now, this is not what people eat. People eat an average of 2,500 man and 2,000 for women. What happened to the missing 700 to 750 calories a day, right? Was it a sheet cake? Was it all broccoli? Like what was it, right? We don't know. The lowest carb diet in that group was 38% carbs. That's not low carb. Low carb is 10%, 5% carbs. And so it wasn't really a valid study. And of course, the low carb eaters, when you look at their other variables, they smoked more, they exercised less, they were more overweight. Of course, they had more deaths, right? And they don't look to quality. So you can see these studies are really challenging. And I feel bad for the average

consumer because they hear the headlines, and they feel like their head's spinning, they don't really know what to do. And unfortunately, we don't have to suffer from that anymore. We can actually look at what's really going on in the biology and forget about drawing these conclusions from these epi studies that are just not solid. There was a great case of a woman who was reported Emma Marano. She was the longest lived woman ever in Italy. She died at 117. When she was a teenager, she was anemic, and her doctor told her to eat three eggs a week. I'm sorry, three eggs a day. Three eggs a day for almost 100 years. And, you know, who knows?

Maybe she would live longer if she ate less eggs. Another guy reported in the New England Journal who was a crazy guy who ate 88 eggs a week. And he was fine. He had no heart disease. So also think about cholesterol. You've got 300 milligrams of cholesterol in an egg, right? Which is not very much. In your blood, you have, let's say 200, let's say your cholesterol is 200. You have 200 milligrams per deciliter. That means you have 2,000 milligrams per liter.

That means you have five liters of blood. That means you have basically 10,000 milligrams of cholesterol in your blood normally. If you add 300, is it going to make a difference? Not really. And all the studies have shown that when you actually eat cholesterol in your diet, it doesn't really have an impact on your lipid levels or your heart disease risk. Now, in fact, cholesterol is essential. It's what we make vitamin D from. It's what we make hormones from, like estrogen and testosterone and our sex hormones. So cholesterol is a really important building block. It's part of our cell membranes and our brain. It's just such a crazy world we live in.

We get this research, and people are frustrated, and they don't understand what to do. And I just want to sort of put some light on this and ask yourself, whenever you look at a study, is it an a study is it An experiment or is it just a correlation study right if it's a correlation study You got to take it with a grain of salt unless the effect is over I would call it to in other words It's a hundred percent increased risk if it's 18 if it's 5 if it's 10 6 I mean it's kind of meaningless and and it doesn't really tell you much. And yet the headlines write it off as if this is the new truth.

And it just contradicts a lot of what we know in the science. And I encourage you to take a smarter look at the data you look at and not just swallow the headlines whole. And yes, you can eat your eggs, so don't worry about it. And we'll see you next time. I just had to do this. I couldn't really stand not saying something about this because it just makes me a little nuts when I see people get drawn into the

headlines and confused about what to do. Be smart. Learn how to read the research. Hopefully, we'll clear this up for you and you don't have to worry about eating eggs. Just go ahead and enjoy your whole egg omelet, but make sure they're pasteurized and they're full of phytochemicals that come from the plants. The orange is the same orange that's in a carrot or in salmon when they eat algae. So those are all good for you. Plus it's got choline and lots of vitamins and nutrients. It's actually the beginning source of nutrition for beginning a whole new life. So don't worry about your eggs. Enjoy them.