Milk does a body good? Maybe not always, Harvard doc argues
Milk: Celebrities are constantly asking if you’ve got any, because, as the long-running ad campaign says, it does a body good. But a Harvard pediatrician is arguing that the current U.S. recommendation of three servings of dairy a day isn’t necessarily one-size-fits-all. For some, it may be a significant source of additional sugar and calories.
“This recommendation to drink three cups a day of milk – it’s perhaps the most prevailing advice given to the American public about diet in the last half century,” says David Ludwig, who wrote the editorial published online today in the journal JAMA Pediatrics. Ludwig is the director of the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital. “As a result, Americans are consuming billions of gallons of milk a year, presumably under the assumption that their bones would crumble without them.”
Drinking reduced fat milk in particular is recommended as a way Americans can meet dairy intake guidelines and also avoid saturated fat, which is linked to weight gain and heart disease. But when the fat is reduced in milk or yogurt products, it's often replaced with sweeteners, which makes it taste better, but also adds sugar and calories.
“The worst possible situation is reduced-fat chocolate milk: you take out the fat, it’s less tasty," Ludwig says. "So to get kids to drink 3 cups a day, you get this sugar-sweetened beverage.”
One cup of low-fat chocolate milk is 158 calories, with 68 calories coming from solid fats and added sugars, according to the USDA . By comparison, one cup of unflavored, reduced-fat milk (2%) is 122 calories, with 37 calories from solid fats and added sugars.
People with a high-quality diet -- those who get adequate protein, vitamin D and calcium from things like leafy greens, legumes, nuts and seeds -- may get little or no added nutritional benefit from consuming three servings of dairy a day, Ludwig argues.
“The point is, we can get plenty of calcium from a whole range of foods,” says Ludwig, who's also a professor of pediatrics at Harvard Medical School and a professor of nutrition at the Harvard School of Public Health. “On a gram for gram basis, cooked kale has more calcium than milk. Sardines, nuts seeds beans, green leafy vegetables are all sources of calcium.”
That’s certainly true for the kale-consuming diet perfectionists among us -- but for many Americans, cow’s milk is an inexpensive, easily accessible source of important nutrients. That’s why Ludwig cautions that for people who are eating a lower-quality diet – especially children – milk is still important.
“For a child or an adult – but especially a child - eating a poor quality diet, three cups a day of milk may be the most helpful thing,” Ludwig says.
Trouble is, we are not great at judging our own quality of diet, says Greg Miller, executive vice president for the National Dairy Council. To skip milk -- but continue to get the recommended levels of nutrients like calcium, vitamin D and protein -- would require a big change in diet for many Americans, he says. The current recommended intake of calcium for adults, for example, is 1,000 milligrams per day for people ages 19 to 50; for those older than 50, it's 1,200 milligrams a day. A cup of cooked kale has about 100 milligrams of calcium; a cup of two percent milk, on the other hand, has about 300 milligrams of calcium.
And kids especially, “aren’t all of a sudden going to start eating bok choy, kale and spinach," Miller says.
Research has linked soda, fruit juice, sports drinks and energy drinks to weight gain, diabetes and heart disease, prompting groups like the U.S. Department of Agriculture and the American Academy of Pediatrics to recommend limiting calorie-containing beverages. However, milk -- even sugary chocolate milk -- is typically left out of the conversation, Ludwig says.
“It’s about the whole big push of, what lengths are we taking to modify plain old milk to get people to drink more?” says Madelyn Fernstrom, Ph.D., certified nutrition specialist and NBC News diet and health editor.
Many nutritionists encourage the three servings of dairy a day recommendation "at any cost," Fernstrom says -- even if that means adding extra sweeteners like chocolate or strawberry flavoring to milk or yogurt to make it tasty enough for kids and adults to actually want to eat or drink it.
“So this newer idea of having low-fat, sweetened milk, like low-fat chocolate milk -- these cancel each other out. You’re cutting out the fat, but you’re replacing it with extra sugar,” Fernstrom says. It's the same with yogurt, too; the added sugar from the vanilla or strawberry-banana sweetener, in many cases, outweighs the nutritional good of the dairy.
“No matter what dairy product you’re choosing, stick with low-fat, but also no sugar,” Fernstrom says. “Cutting down the fat in yogurt and milk but adding extra sugar – that’s a wash" when it comes to heart health.
Miller believes getting kids to stop drinking sugar-sweetened beverages like soda is a bigger battle than flavored milk.
In his editorial, Ludwig recommends broadening the current recommendation from “three” to “zero to three,” something that Fernstrom says makes sense for some people. (Switching to non-dairy milks like soy or almond is also an option -- but keep in mind that these are good sources of calcium, but poor sources of protein, Fernstrom says.)
“This will depend upon the quality of your overall diet,” Fernstrom says. “But even in the best of circumstances, dairy products are part of a balanced diet.” She calls dairy a “triple-duty food,” in that it provides protein, calcium and vitamin D. “These are three big nutrients that many Americans don’t get enough of elsewhere.”