Strong Bones Linked to Breast Cancer

A new study links having strong bones to an elevated risk of breast cancer. At first blush, that seems to put women in a bind: tumor if you do, fracture if you don't. The temptation to punch a wall in frustration is totally understandable. (Hey, if your bones are strong, at least you won't break your hand!) But you certainly shouldn't be misled by these results into believing that doing things to make your bones stronger—like lifting weights and taking calcium—will increase your breast cancer risk. The new finding doesn't have any such sinister implication.

Sizing up breast cancer risk in women over 60 is tricky business. The standard risk model takes into account, among other things, age, race/ethnicity, and family history of breast cancer, yet it produces only a rough estimate of a woman's risk. The new study, published online today in the journal Cancer, found that hip bone density, which can be measured with an X-ray scan, is just as good a predictor. What's more, combining the density scan with the risk model could more accurately pinpoint risk for women already at heightened risk for breast cancer, like those who've previously had breast biopsies.

That's a potentially important finding, but it doesn't mean that strong bones promote breast cancer. For some women, strong bones could be a sign that they've got higher levels of estrogen in their bodies, which increases both bone mass and breast cancer risk. Overweight women, for example, tend to have stronger bones and a higher breast cancer risk, probably because estrogen is churned out in body fat. Women who have one or more alcoholic drinks a day fall into the same category, also because of the estrogen connection; read my previous blog to learn how much you can safely drink.

Fortunately, the bone-building benefits from exercise and calcium have nothing to do with estrogen. Probably the best way to respond to the new study is to step up those healthful habits. Adding 10 minutes to your daily walk could help strengthen your bones and, by burning excess fat, lower your breast cancer risk. Switching from high-calorie cocktails to, say, light beer still provides bone benefits with a calorie savings that can help you get to a healthier weight.

Oh, and about punching that wall? I don't recommend it. I accidentally swiped my bedroom wall four years ago while trying to demonstrate for my sons how Yankees pitcher Kevin Brown broke his hand punching a locker-room wall—a lesson for them on how not to handle their anger. Left a bruise on my knuckles for months.