If I were to ask “What’s killing you?” you’d probably come up with a few dozen things—alcohol, cigarettes, candy, chemtrails—before you got anywhere near cheese. Dr. Neal Barnard, president of the Physicians Committee for Responsible Medicine and a longtime advocate of plant-based diets, sees things differently. His new book The Cheese Trap makes the compelling case that the beloved dairy product is at the root of what ails us. The book provides a scientific but accessible look at all the ways cheese could be doing us wrong. It links cheese addiction to a series of common maladies, from the expected (heart disease, obesity) to the unexpected (asthma, acne, erectile disfunction).

While the book’s anti-cheese vendetta is novel, its larger point that we should eat more plants and fewer animal products is pretty common advice. A few of the anecdotes in the book are a bit harder to swallow. At one point, Dr. Barnard shares the stories of people who were cured of cancer and endometriosis upon switching to a vegan diet. But the patients’ personal doctors said there’s no way that diet could cure such things. Dr. Barnard told me that he’s not “some zealot who thinks that a vegan diet is going to cure all sorts of cancers,” though in some cases “it might.” I’m wary of such dramatic claims, but he says, “My job is to give people information about what has happened and not to overstate things or to understate things.” I’m not about to stop eating cheese, or even curb my cheese intake, but I guess it seems like good advice.

I called Dr. Barnard on the phone to find out more about what he has against cheese. We spoke about how cheese is like heroin, the problem with those “fat is good now” headlines, and why he thinks cheese will ultimately disappear from our diets.

Extra Crispy: Why single out cheese?
Dr. Neal Barnard: Years ago, when we were doing research studies, we would use vegan diets to help people with diabetes. They did really well. People would lose weight, their cholesterol would fall, and they would feel great. But I kept hearing people say that the one food they craved was cheese. Not everybody, but I kept hearing this frequently enough that it was clearly a phenomenon that many people just feel hooked on cheese. Not ice cream, not milk, not yogurt, not steak—specifically cheese. When we started looking into it, we discovered a number of things. Number one, it’s surprisingly fattening. Number two, it contributes to a surprising range of health issues, from joint pains to headaches to bad skin, that you wouldn’t normally connect with cheese. And third, it seems to be, for all intents and purposes, addicting. 

A lot of the health problems that come from cheese are basically caloric in nature. Cheese can be so small and calorically dense that people end up overeating. What are the issues that are particular to cheese beyond the fact that it’s an easy way to quickly consume tons of calories?
It’s not just that it’s easy to overdo it. People will eat it even when they’re not hungry. There was a study at the University of Michigan where they asked people which foods they have trouble with overeating. They looked at ice cream and chocolate and chips and cookies, but the number one was pizza, and I’m fairly sure it’s not because of the sun-dried tomatoes. There’s something about that gooey cheese that makes people eat it even when they are already full. It’s sort of like a last line of cocaine that they’re consuming.

The other problem is that cheese is fat and protein, basically, plus hormones and cholesterol. The fat is where the calories are jammed in. There’s saturated fat, which is related to alzheimer’s disease and heart disease. The protein, which is in milk but concentrated in cheese, is what we believe contributes to sensitivities. When I say sensitivities I mean autoimmune conditions like rheumatoid arthritis, skin conditions, asthma, and migraine headaches. 

I’m curious why you think we don’t hear very much about this in the press?
You will. That’s why I wrote the book. Three years ago I released a book called Power Foods for the Brain because I was convinced nutrition was a key issue in Alzheimer’s disease. When I released the book, reporters said exactly what you just said: “What are you talking about? I’m a well-read person and I’ve never heard that food has anything to do with Alzheimer’s disease.” I wrote it specifically because I needed to break through this collective somnolence. That’s where we are now with cheese. 

You mention that the amount of cheese we consume has gone up drastically over the last century.
In 1909, the average American consumed 3.8 pounds of cheese in an entire year. It was something Swiss people consumed but not people in Peoria. But fast food chains in the ‘60s and ‘70s put slices of cheese on every sandwich. Then pizza started becoming popular, and the cheese on it was piling higher and higher. Now you’re just not an American unless you’re having pizza with 3/4” of yellow asphalt on top of it.

That’s a huge increase in cheese consumption. Meanwhile an average American only gains about 1.5 pounds per year; that’s still significant but nothing like the 30-pound increase. So why recommend eliminating cheese instead of just limiting consumption to 15 or 20 pounds per year?
There’s nothing in it that’s good for you, and there’s lots in it that’s bad for you. Cheese is mostly saturated fat, and your body doesn’t need any saturated fat. It has no requirement for it. It’s linked to Alzheimer’s and heart disease, so you’re really better off without it. The proteins lead to a variety of conditions, and the links with prostate cancer are, to my read, convincing. Even though your average 65-year-old guy will gladly bend over the exam table and have his prostate checked, but the doctor will unlikely tell him what he can do to prevent the condition. 

Can you elaborate on that link between dairy and prostate cancer?
It started out with just comparisons between countries. Countries that avoided dairy, like Japan and Hong Kong, didn’t have much prostate cancer compared to Scandinavian countries or the US. That’s just an association, that’s not the smoking gun. Then, at Harvard, they launched the Physician’s Health Study with 21,000 healthy, cancer-free doctors. They tracked their diet and found that as the years went by, those who consumed the most dairy had 34 percent increased risk of prostate cancer. That’s one very good study, but just one study. So they did another study called the Health Professional’s Follow-Up Study. As time went on, exactly the same thing showed up. Men who consumed the most dairy had in this case a 60 percent risk of higher prostate cancer. Several other studies have come out, and the evidence is pretty well accepted now that milk is associated with prostate cancer. The reason we think this happens is because milk is designed to help a calf grow. It contains fat and sugar and protein, but it also contains hormones and causes hormonal changes in the animal’s body. Specifically, milk increases a substance in the blood called IGF1, [which stands for] insulin-like growth factor No. 1. IGF1 is a potent stimulus for cancer cell growth. For a baby, growth is good, but for a person who’s already full grown, further growth is cancer.

You also say that we need to stop eating cheese because we’re addicted to it.
I don’t argue with people who get upset with how the word addiction is used. We went through this with chocolate, where there were psychiatrists saying that nobody’s really addicted to chocolate. But then others said, wait a minute, I see tons of people who can’t stop eating it. That caused people to define addiction in a different way. 

What we learned a long time ago is that if something is like an addiction, whether it’s physical or not, that means you’re better off not having any. It’s easier not having a single cigarette than to try to have one a week. When you tease yourself with it, it just lures you back. Many people say, “If I haven’t had cheese in a month I don’t think about it. But if I had it yesterday I crave it today.”

Secondly, we need social support. I run lots of groups here. When people have social support they can break their addictions and they can stay on the straight and narrow with food. I think thinking of it as an addiction is a really handy thing.

That said, when we discovered casomorphin, it’s pretty hard to argue that there’s something physical going on. There are compounds in the dairy protein that are released during digestion that do pass through to the brain, they are measurable in cerebral spinal fluid, they attach to the μ receptors in the brain just like heroin.

Like heroin?
These are opiates. They are in the same chemical class as morphine and heroin. But opiates vary in how strong they are and how strongly they bond to receptors. The most potent casomorphine has about one tenth the binding power of pure morphine. It’s not going to make you drive funny, but it is strong enough, we believe, to make you really want it and to make you come back again and again, even when you’re not hungry.

It seems like every few months there’s a new article about what foods are actually good or actually bad. “Fat is OK” or “sugar is poison” or now “cheese is bad.” What do you say to people who don’t know what to believe?
I feel your pain. I don’t have a good answer. The dairy industry has specifically tried to make saturated fat look not so bad, in the same way that the egg industry has tried to make cholesterol look not so bad. One way of doing that is getting a reporter to say that saturated fat really isn’t so bad, even though scientists over the years have said it contributes to heart disease and other heart problems.

So how am I going to make a reporter do that? They don’t take evidence from just anybody; they take it from research that’s published in a journalSo if I want to get them to write something, I have to do a study, and the kinds of studies that get their attention are meta-analysis. A meta-analysis means you take many different studies and combine the results into a single study. For example, let’s say there are 20 studies that have looked at saturated fat and heart disease. If they came to different conclusions, you could combine the results of all these studies into one single study and give an answer. That’s a highly respected form of research. The problem is that if the studies were very different, they tend to cancel each other out.

There was a study that looked at populations that range from vegan to vegetarian to meat eaters, had a broad range of saturated fat intake, from very low to very high. The pattern was crystal clear: Those who had the highest saturated fat intake had more heart disease. There was another study done in Sweden where everybody in the population had a high fat intake. There wasn’t really any low group so they didn’t have much range so they couldn’t really make any pattern with regard to saturated fat intake. It’s the equivalent to trying to show that tobacco causes cancer when you don’t have a single non-smoker to compare them to. The researchers themselves said they didn’t think it’s a very good study because they don’t have anybody whose intake was low. A meta-analysis was done that took both of these studies, combined them together with other studies and their conclusion was, we don’t really see any clear pattern so forget about it. Then the Times wrote, “Butter is back.” It was all a statistical problem. How can the average reader tease all that apart? They can’t. That’s the reason that I write books and I try to make sure that they are clear and understandable, fully-referenced, and then I do lots of interviews. You will hear contrary messages from other people, I can only tell you that I take my work very seriously and I am also right [laughs].

So your hope is that, over time, there will be more reporting and more research until this idea becomes the common view? 
Look at the big picture: People have said, oh, carbohydrates are the devil, don’t eat potatoes and bread and rice. Wake up. Take a look around the world. In Japan, you have the thinnest, longest-lived people on the planet. What have they been eating for 1000 years? They eat phenomenal amounts of rice. What happened when McDonald’s set up shop in Tokyo and rice consumption started to fall and meat and cheese started to increase? They got heart disease, their waistlines expanded, and they got diabetes like they never had before.

What do you think the general reaction to The Cheese Trap book will be?
This is also an area where you’re dealing with something people have never thought about before. They’re thinking about losing weight and they don’t feel healthy, and so it does raise this conflict in their minds. “Do I stick with my old culture, or do I get healthy?” My answer is, explore, have fun with it. I think what is going to win this out is culture. Take Tom Brady, the winningest quarterback ever. You say, "How much cheese today, Tom?" He’ll say, “I don’t ever touch cheese. None.” Aaron Rodgers is the quarterback of the Green Bay Packers. When he announced he’s dairy-free in Wisconsin, it made headlines: “Our own quarterback won’t have any cheese.” Venus Williams, Serena Williams, Djokovic—they’re all dairy free because they can’t afford to be inflamed and stiff and have poor recovery. When you see a trend like that, and you go into a grocery store and the milk aisle is half soy and rice milk, the culture is just changing. Yes, The Cheese Trap will be very controversial. But in three years, everyone will say, “Well, of course we all know cheese is unhealthy.”