SCIENCE 02.22.2021 Don’t feel sheepish reaching for that manchego. Cheese doesn’t deserve its unhealthy reputation.
CHEESE IS AMONG the ultimate guilty pleasures. It’s gooey. It’s fatty. It’s delicious. It just has to be bad for you, right?
Wrong. A large body of research suggests that cheese’s reputation as a fattening, heart-imperiling food is undeserved. When it comes to weight and other key health outcomes (and setting aside the issue of lactose intolerance, with apologies), cheese is neutral at worst, and possibly even good for you. And yet that research doesn’t seem to have broken through into common knowledge. If you Google “cheese,” the top result under “people also ask” is the ungrammatical query “Why cheese is bad for you?” Now, if you’re the type of person who’s thinking, “What’s the big deal? I eat what I like, in moderation, and don’t worry about calories”—congratulations, I’m happy for you, we have lots of great articles about science and tech you might enjoy. If, on the other hand, you’re like me and worry that your diet is making you gradually fatter, keep reading.
The best evidence for the benign impact of cheese comes from long-term cohort studies that tracked the health and eating habits of tens or hundreds of thousands of people. A 2011 paper published in the New England Journal of Medicine analyzed three cohorts that together tracked 120,877 US adults over several decades. The authors found that foods like potatoes, processed meats, and refined grains were associated with weight gain over time, while yogurt, fruit, and nuts were associated with weight loss. Cheese was right in the middle: On average, eating more or less of it had essentially no effect on weight.
That finding has held up in more recent research. A 2018 analysis of a study of 2,512 men in Wales, for example, showed a mild inverse relationship between cheese consumption and body mass after five years, meaning eating cheese was associated with weight loss, though that effect faded at the 10-year mark. A meta-analysis of 37 randomized clinical trials found that increased dairy consumption overall led to increased lean muscle mass and decreased body fat.
“There’s almost no evidence that cheese causes weight gain—and in fact, there’s evidence that it’s neutral at worst,” says Dariush Mozaffarian, the lead author of the 2011 paper and dean of the Tufts Friedman School of Nutrition Science and Policy. “There’s no evidence that cheese is linked to cardiovascular disease, and in some studies, it’s even a little bit associated with lower risk. And then, for diabetes, again, it’s at worst neutral, and maybe protective.”
The Future of Food
It’s true that observational studies can only reveal correlations. But if there are confounding variables when it comes to Americans’ cheese consumption, they should make its effects look worse, not better. The way Americans eat cheese, and especially the way they were eating it in the 1980s and ’90s, when much of the data was gathered, tends to pair it with unhealthy foods: Imagine a pepperoni pizza, or a ham and cheese sandwich on white bread with a side of chips. “It wasn’t people eating cheese on cutting boards with walnuts and grapes,” Mozaffarian says. “If there were confounding [factors], it would be toward weight gain.”
So just to recap so far: The evidence tends to show that cheese does not make you gain weight. Why hasn’t this amazing news spread more widely? After all, we’ve seen many conventional ideas about food, weight gain, and health be reconsidered over the past decade or two. Thanks in part to the work of authors like Michael Pollan and Gary Taubes, the low-fat diet mantra of the late 20th century has been discredited, replaced by an awareness that added sugars, refined carbohydrates, and processed foods are the likelier culprits in America’s obesity epidemic.
Still, many nutritionists and ordinary people adhere to the old notion that weight gain or loss is a pure function of “calories in, calories out”—that is, how many calories you consume, regardless of the food source, minus how many you burn. Under this thinking, fatty foods are to be avoided because a gram of fat has 9 calories compared to a gram of protein or carbohydrate, which only has 4. “There still is this long-standing perception bias that fatty foods make you fat, or calorie-dense foods make you fat,” says Mozaffarian.
It’s worth noting, however, that even under the net calorie theory, it doesn’t make much sense to think of cheese as a particularly fattening food, for the simple reason that it isn’t actually all that caloric. I have in my refrigerator a package of cheddar cheese that contains 110 calories per ounce. Meanwhile, a package of whole-grain crackers in my pantry contains … 110 calories per ounce. There is stuff in cheese other than fat, and when you take the food as a whole, cheese turns out to be no more calorie-dense than lots of everyday carb-based foods.
And that’s only relevant if you still cling to the net calories formula, which fewer and fewer nutrition experts do. Experimental studies have shown that animals and humans fed identical numbers of calories, from different food sources, gain different amounts of weight. Other research shows that calorie intake and expenditure are not independent; cutting back on calories can lower the rate at which the body burns them, thwarting weight loss. Cohort analyses like the ones I mentioned above show that super-high-calorie foods like nuts are correlated with long-term weight loss. (One ounce of dry-roasted almonds: 168 calories.) Food is complex, and so are bodies; we don’t seem to process a calorie in a piece of fish the same way we do in a piece of cake.
In the case of cheese, there could be several reasons for the surprising lack of impact on weight, though more research is needed. Cheese is fermented, meaning it has live bacterial cultures. That could have a positive effect on the gut microbiome, which appears to play a role in weight regulation. The fermentation process also creates vitamin K2, or menaquinone, which experimental studies have linked to improved insulin function. Insulin regulates blood sugar levels, hunger, calorie expenditure, and fat storage. (One upshot is that hard, aged cheeses, which are more fermented, probably provide more benefit than soft, less fermented ones.) There’s also some promising research about the benefits of a compound called the milk-fat globule membrane, which is intact in cheese but not in milk or butter.
Other high-fat foods, like avocados, have lately enjoyed a reputational rehabilitation. Cheese, not so much. One reason may be the fact that cheese contains not just a lot of fat but a lot of saturated fat, a major dietary scofflaw linked to higher blood cholesterol and rates of cardiovascular disease. But here, too, the science says cheese doesn’t deserve its stigma. While cheese does have high saturated fat, that doesn’t appear to correlate with higher risk of heart disease. A study of 5,209 US adults published in 2012, of which Mozaffarian was a coauthor, found that saturated fat from meat was associated with higher rates of cardiovascular disease, but that saturated fat from dairy was associated with lower rates. Two meta-analyses of cohort studies with hundreds of thousands of total subjects likewise concluded that cheese consumption, specifically, was correlated with lower risk. (There have been similar findings for diabetes. An analysis of a 26,930-person Swedish cohort found that consumption of cheese was associated with lower risk of diabetes in women. The production of menaquinone in the fermentation process could have something to do with that.)
“The bottom line is that the bad reputation that cheese has regarding its adverse effects on cholesterol, and hence on heart disease, is undeserved for the most part,” says Ronald Krauss, a professor at the UCSF School of Medicine and an expert on diet and cholesterol. “The saturated fat is really composed of saturated fatty acids in a structure that forms a fat. Those saturated fatty acids come in many different forms, and they can have very different biochemical effects. And most of them can raise blood cholesterol, but not all of them do.”
Both Krauss and Mozaffarian say that, despite the promising research, there still isn’t enough good data to say conclusively that cheese prevents heart disease or obesity. What is clear, however, is that eating normal amounts of cheese at least doesn’t appear to raise the risk, on average. “I spend a lot of my time with patients giving dietary advice, and I tell them, ‘Don’t worry about cheese,’” Krauss says. “They love it.”
Of course, there are reasons for some people to avoid cheese. Krauss cautions that everyone’s body is different, and people with stubbornly high cholesterol might still benefit from cutting out cheese. Highly processed varieties, in particular, can be high in sodium and other ingredients people might be trying to limit. If you’re vegan, whether it’s because of animal cruelty or climate change, I’m not trying to change your mind. (According to an analysis by Helen Harwatt, a fellow at Harvard Law School, global dairy production accounts for about 3.6 percent of greenhouse gas emissions.) The point is merely that a lot of people love eating their aged Gouda, their sharp cheddar, and indeed their funky Gorgonzola, and as far as health is concerned, they don’t need to feel guilty about it.
Perhaps the real reason the good news hasn’t caught on widely is that the evidence so far reveals cheese to be neither a superfood, like yogurt, nor a mass killer, like sugary soda. (That might change if more research confirms a 2020 study that found that cheese protected against age-related cognitive decline.) This makes it harder to know what exactly to do with the information.
Mozaffarian puts cheese in the middle of his personal three-tier food pyramid. At the top are “protective” foods, which include fruits, beans, nuts, fish, yogurt, and minimally processed whole grains, of which Mozaffarian advises eating a lot. At the bottom are foods that he avoids, like refined carbohydrates and processed red meat. Neutral foods, like cheese, go in between.
“We can’t always eat the healthiest possible thing,” he says. “We need neutral foods for variety, fun, palatability, so cheese is up there on my list. If I’m not going to have the absolute best—fruits, nuts, seeds, fish—cheese is great. And if you add it to those other foods, it’s fantastic.”
Personally, I find this advice liberating. I used to avoid adding cheese when I made pasta, on the assumption that it was just making my dinner more fattening. Now I realize that I’m better off getting full from a bit less pasta—a refined grain—and a bit more cheese, perhaps a nice aged Parmesan. It’s also an easy way, almost a hack, to improve a healthy but unexciting meal, like the leftover quinoa with vegetables that I had for lunch this week. It was fine—until I stirred in about a tablespoon of goat cheese, which made it amazing. Is a guilty pleasure as pleasant when you remove the guilt? In this case, I’m inclined to say yes.
Updated 2-23-2021, 3:10 pm EST: The 2018 analysis looked at a study of 2,512 men in Wales, not in Ireland as previously stated.