Growing up, we’re often told by our parents that we need to drink plenty of milk, that the calcium will ensure we have nice, strong bones. The U.S. Department of Agriculture DA backed up dear old mom and dad, recommending that adolescents drink at least three glasses of milk (or dairy equivalent) every day. Unfortunately—for teen boys anyway—drinking milk may actually be causing more fractures than it prevents.
Researchers, led by Diane Feskanich, an assistant professor in the department of medicine at Brigham and Women’s Hospital and Harvard Medical School, analyzed bone fracture histories taken from close to 100,000 middle-age-and-older men (35,000) and women (62,000), and compared that with each subject’s recollection of his or her milk-drinking as a teen.
“What we found was a little surprising,” said Feskanich. “Teen milk consumption was associated with a higher fracture risk among men, but not women.” Feskanich was the lead author of a study based on that research that was published in JAMA Pediatrics.
According to the researchers, the USDA’s recommendation is based on the fact that the teen years are when boys and girls develop 95% of the bone mass and mineral content that will take them into their adult years. The idea is that all that milk drinking would led to proper skeletal growth. The problem, say Feskanich and her colleagues, is that drinking milk can spur growth and, oddly, growing taller is associated with increased risk for fractures.
After factoring out anything that might otherwise contribute to fractures (such as current diet and milk consumption, exercise level, prescription drug use, smoking history, and weight), the researchers concluded that for men, every daily glass of milk chugged in the teen years increased his risk of hip fracture by 9%.
Interestingly, for women, teenage milk drinking didn’t affect adult fracture risk.
Be aware that there could be some problems with the accuracy of the study’s data. After all, given that most of us have trouble remembering what we had for breakfast last week, how reliable are our recollections of milk-drinking habits 30 or 40 years ago or longer?
So, of course, before you or your sons stop buying milk, talk this over with your doctor.