Milk for Your Bones?
Is Milk Best?
Milk: Does It Really Do a Body Good? continued...
To buttress her point, Herlock points to a portion of the Harvard Nurses' Health study published in the June 1997 issue of the American Journal of Public Health. The study found that women who ate lots of dairy products had higher rates of bone fractures than women who rarely touched the stuff. It suggested that drinking more milk didn't provide any substantial protection against hip or forearm fractures in middle-aged and older women, writes Diane Feskanich, ScD, a professor at Harvard Medical School in Cambridge, Mass., and the study's lead author. "We considered the possibility that dairy protein was responsible for the increase in risk of hip fractures," she says.
Milk advocates pooh-pooh the protein concern. The amount of calcium lost in the urine from drinking a glass of milk is trivial compared with the amount of calcium coming in, says Connie Weaver, PhD, head of foods and nutrition at Purdue University in West Lafayette, Ind. "For every gram of protein you eat, you lose 1.75 milligrams of calcium." Using this calculation, since each glass of milk provides 8 grams of protein, you'll lose 14 out of 300 milligrams of calcium per glass -- which doesn't seem so bad. In fact, because the average American consumes approximately 75 grams of animal protein a day (though of course not all from milk), you'll still take in more calcium than you lose by drinking just one glass of milk (you'll consume 300 milligrams of calcium and only lose 131 milligrams).
Robert Heaney, MD, a professor of medicine at Creighton University in Omaha, Neb., who specializes in bone biology, also shrugs off dairy dissenters. "The reason why dairy products work is that they contain not only calcium and protein but also phosphorus, magnesium, vitamin D, potassium, and other things associated with good bone health," he says. "It's the logical way to go."
The Wonders of Workouts
My mother, clearly pro-dairy, consumes lots of calcium and is determined to fight osteoporosis head-on. For a woman about to turn 60, her bones are in great shape. But according to one recent study that dairy doubters add to their arsenal, she has more than milk to thank for that bragging right.