I’ve always assumed that exercise reduces the risk of cancer, contributing to the well-established fact that folks who exercise live longer than others.
But a recent study found a positive association between exercise and two cancers: melanoma and prostate. “Positive association” means the more you exercise, the higher your risk of melanoma and prostate cancer (if you have a prostate).
The good news is that exercise was linked to lower risk of 13 other cancers.
Here’s a quote for the New York Times Well blog:
The researchers found a reduced risk of breast, lung and colon cancers, which had been reported in earlier research. But they also found a lower risk of tumors in the liver, esophagus, kidney, stomach, endometrium, blood, bone marrow, head and neck, rectum and bladder.
And the reductions in risk for any of these 13 cancers rose steeply as people exercised more. When the researchers compared the top 10 percent of exercisers, meaning those who spent the most time each week engaging in moderate or vigorous workouts, to the 10 percent who were the least active, the exercisers were as much as 20 percent less likely to develop most of the cancers in the study.
I’m surprised the protective effect of exercise against cancer wasn’t stronger.
So how much physical activity does it take to prevent cancer? And what type of exercise? We await further studies for specific answers.
I’m hedging my bets with a combination of aerobic and strength training two or three times a week.
Steve Parker, M.D.
PS: If you think cancer’s bad, read one of my books. Wait, that didn’t come out right.