Growing up lactose intolerant, I was fond of saying that drinking milk post-infanthood was unnatural. Then I found out that humans aren’t the only ones in the animal kingdom to keep and care for another species in order to take its produce. This week, a writer at Jezebel wrote an amusing clickbait article—and an effective one if my Facebook feed is any indicator—echoing my childhood sentiment that adults drinking milk is weird and they shouldn’t do it.
Setting aside her really bad arguments (e.g., adult humans shouldn’t drink milk because no other animals do so), her “best,” or at least most reasonable, argument centers on the nutritional quality of milk. She contends that its high-fat, nutrient-dense nature makes milk perfect for babies in need of rapid weight gain and nutrition, but inappropriate for adults, especially since most of us already eat too much fat and fat consumption causes heart disease. “If you enjoy living, put the milk down,” she says. It’s funny, but based on current scientific evidence, dead wrong.
For decades the theory—or rather dogma—was that saturated fats (SFA) in foods caused cardiovascular disease (CVD). This idea that came from observational studies that linked consumption of foods high in SFA to increased CVD risk. And this is at the heart of the nutrition argument Jezebel and even the most recent USDA Dietary Guidelines make. While there is some research to back up the idea that consumption of foods containing saturated fat might increase heart health risks, emerging research has begun to cast doubt on the old wisdom. You may have seen articles with titles like “The Questionable Link Between Saturated Fat and Heart Disease” and “The Government’s Bad Diet Advice” in major news outlets asserting that the saturated fat myth has been “debunked.” It turns out that it’s not so simple and that not all saturated fats are created equal.
“Saturated fat” isn’t one kind of fat but a class of fatty acids which includes, among others, butyric, lauric, myristic, palmitic, stearic acid. As Dr. David Katz—who has been skeptical of the turning tide on saturated fat—noted a few years ago, when it comes to heart disease risks, stearic acid (found in meat fat and cocoa butter) seems to have no harmful effects while palmitic acid (found in palm oil, meat, and dairy fat) and myristic acid (found in coconut oil and dairy fat) seems to have potentially harmful effects on health. What he doesn’t mention is butyric acid (found in butter and dairy fat) seems to show beneficial effects on human health. These varying effects of different types of saturated fatty acids could be the reason—at least in part—for so much confusion about the effects of “saturated fat.”
Yet, as researchers begin to look closer at particular types and sources of saturated fat, one thing has become clear: dairy fat in the diet is linked to lower body fat, reduced risk for diabetes, and lower risk for heart disease. This is despite the fact that, as the Jezebel author correctly assumed, full-fat dairy is high in saturated fat. For example, this 2013 meta-analysis published in the European Journal of Nutrition, which analyzed studies looking at the link between dairy fat consumption, obesity, and heart disease and found that 11 of the 16 studies examined showed inverse associations with high dairy-fat consumption while studies showed either no or inverse association with dairy fat and both diabetes and cardiovascular disease.
Despite the turning tide in the world of research on saturated fat, most people still believe that all saturated fat contributes to obesity and heart disease. This may be part of the reason people feel better about consuming carb-based foods instead of red meat, margarine instead of butter, and skim instead of whole, to the detriment of their health and waistlines. Research in recent years seems to show that people who consume full-fat butter, milk, and cream are less likely to be obese. And recent analyses show that people who consume full fat dairy are less likely to die from cardiovascular issues than those who consume low-fat dairy or none at all. So, while Jezebel may recommend us adults “let that glass of thick, cloudy water go,” my advice would be: don’t take dietary advice from Jezebel.
Much thanks to the researchers at STATS.org for their assistance in assessing clinical research related to this post.