For years, researchers have looked for behaviors that might help prevent cancer. They've found that reducing alcohol intake and controlling weight reduces the risk for several kinds of tumors. Some data have also indicated that women who exercise develop breast cancer less frequently, but that relationship has been less clear.
Now Graham Colditz, an epidemiologist from Washington University in St Louis, Missouri says he has enough information to state more definitively that exercise reduces breast
cancer risk in pre-menopausal women. Colditz and his colleagues looked at data from the Nurses Health Study II. It's a large study that's been following the health of tens of thousands of nurses for several decades.
The study recorded a detailed history of exercise in adolescence and through adult life? And we ended up with the data on exercise patterns on about 65,000 women who we then followed forward for six years, so we could relate their recorded activity level to their subsequent risk of breast cancer.
He says after those six years, and beyond, subjects who had exercised as young women had a lowered risk of breast cancer.
These data showed that women who exercised at the level of running for about a half an hour a day, had a 25% reduction in breast cancer risk up to the age of menopause?
Colditz says the benefits exist no matter what the exercise - it could be walking or dancing.
Often one sees the argument that being active at the level that you break out of sweat, or some other level is what is needed to get a health benefit. And what we have seen here is that it really is the total activity, the walking plus other activities all added up together that gives us the clearest signal of reduced risk of breast cancer.
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