Does a Body Good? New Study Adds to Milk’s Growing Image Problem
Long a staple of weekly grocery lists, the snow-white picture of purity, the unassailable go-to drink for good health, milk—yes, milk—is experiencing something of an image problem. The dairy identity crisis is no doubt thanks to a growing number of studies like the one released this week out of Sweden that suggests moo juice isn’t the magic elixir it has long been cracked up to be.
The new research calls into question one of those pieces of conventional wisdom that few of us would even think to disagree with. We all know that calcium-rich milk helps to build strong bones, right? For adults, that’s supposed to mean fewer bone fractures. Maybe not. A vocal chorus of public health experts, including those at the Harvard School of Public Health and the Physicians Committee for Responsible Medicine, have long pointed out that there’s little scientific evidence to support the notion that drinking milk leads to better bone health—and not enough to justify the current federal dietary recommendation of drinking three cups a day. The new study, published in the journal BMJ, would seem to add more fuel to this skepticism. Researchers reviewed the detailed dietary information of more than 100,000 Swedish women and men and tracked their health outcomes for up to 23 years, and they found no evidence that drinking more milk correlated with a decreased risk for bone fracture.
Among women, the results were most surprising. Women who drank at least three glasses of milk a day (which is consistent with U.S. guidelines) were 16 percent more likely to experience a bone fracture—and 60 percent more likely to break their hip—than women who drank less than one glass a day.
Even more alarming, women who drank more milk were 90 percent more likely to die of cardiovascular disease and 44 percent more likely to die from cancer during the course of the study.
Milk-drinking men fared better, in the sense that those who drank three glasses of milk a day were “only” 10 percent more likely to die earlier, a risk that researchers tied to a 16 percent greater chance of suffering from cardiovascular disease.
Bottom line: Researchers found no positive health benefits from drinking more milk. On the contrary, the study suggests that drinking too much milk might do a body more harm than good.
But the news wasn’t all bad for the dairy industry. Unlike milk, fermented dairy products such as yogurt, cheese, sour cream, and buttermilk appeared to have at least some protective benefits, at least for women. As the Los Angeles Times reports:
Among all of the women in the study, those who ate more of these fermented dairy foods had lower rates of fractures and premature death compared with women who ate less of them. Each additional serving corresponded with a 10 percent to 15 percent reduction in the risk of both, the researchers found. However, the effects for men were ‘more modest’ or ‘non-existent,’ according to the study.
The study’s authors weren’t able to determine why this was the case, although they have a theory. While milk is notably high in lactose, fermented dairy products aren’t (the fermentation process eats up the lactose). When the body metabolizes lactose, it generates something called D-galactose. Prior animal-based studies have found D-galactose isn’t so great for the body, causing “oxidative stress damage, chronic inflammation, neurodegeneration, decreased immune response, and gene transcriptional changes.” As the Times points out, “when scientists want to mimic the effects of aging, they give animals shots or food containing D-galactose.”
As the Swedish research team admits, none of this is conclusive evidence that milk is bad for you. But for many health experts, there’s now enough science to debunk the notion that you can never get enough milk. The Physicians Committee for Responsible Medicine cites a litany of studies that have found milk consumption does not lead to healthier bones in children, adolescents, or adults, while drinking milk has been linked to a higher risk for certain cancers.
For its part, the Harvard School of Public Health doesn’t even list dairy as part of its “Healthy Eating Plate,” which it developed as an alternative to the federal government’s “MyPlate.” Harvard’s diet guide is “based exclusively on the best available science” and is not subject to “political or commercial pressure from food industry lobbyists”—like the dairy lobby, which has doubled its political contributions over the last decade, according to the Center for Responsive Politics.
As the Harvard website explains: “It’s not a news flash that calcium is key for healthy bones. Getting enough calcium from childhood through adulthood helps build bones up and then helps slow the loss of bone as we age. It’s not clear, though, that we need as much calcium as is generally recommended, and it’s also not clear that dairy products are really the best source of calcium for most people.”
So what are some arguably better sources? Nutrition experts say you can get plenty of calcium from leafy greens (kale, bok choy, and collards are particularly calcium-rich), beans, and fortified beverages such as soy milk and orange juice.