Strenuous exercise lowers lifetime breast cancer risk
NEW YORK (Reuters Health) - A new study confirms that for most women, 6 or more hours of strenuous recreational exercise each week can reduce the risk of invasive breast cancer, according to the findings of a new study.
While women with a family history of breast cancer didn't have a reduced risk with exercise, all of the other women did, regardless of how old they were when they started exercising, Dr. Brian L. Sprague of the University of Wisconsin-Madison and colleagues found.
"A lot of women are particularly concerned about breast cancer, and our study just adds more evidence that physical activity is indeed related to breast cancer risk," Sprague told Reuters Health.
His team interviewed 7,630 women who were free of breast cancer, 1,689 with very early-stage or in situ disease, and 6,391 with invasive breast cancer. All of the women ranged in age from 20 to 69.
While there was no link between physical activity and in-situ breast cancer risk, women who reported more than 6 hours of strenuous recreational exercise each week had a 23 percent reduced risk of developing invasive breast cancer compared to women who never exercised.
The reduction in risk was seen women who exercised early in life, after menopause, or in the recent past.
Sprague noted that there were relatively few women in the study with in situ disease, so it may be that the study was not powerful enough to identify a reduced risk with exercise, which other studies have reported. It's possible, he added, that exercise may prevent invasive breast cancer by stopping in situ disease from progressing.
The researchers found no link between physical activity on the job and reduced breast cancer risk. However, Sprague noted, he and his colleagues had to use a fairly crude measurement to gauge occupational activity, based on job titles, so the current study does not necessarily mean on-the-job activity is not protective.
SOURCE: Cancer Epidemiology Biomarkers & Prevention, February 2007.
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What breastcancer.org says about this article…
Strenuous exercise lowers lifetime breast cancer risk
The study reviewed here adds to the growing amount of information on the role exercise can play in staying healthy. The link between exercise and cardiovascular health has been documented in many studies. The link between exercise and a reduction in breast cancer risk is less clear but no less important.
In this study:
- Women had to do SIX or more hours of STRENUOUS exercise each week to reduce their risk of breast cancer. This probably means that this amount and type of exercise needs to planned as part of your weekly routine. Casual walking a couple times a week probably isn't enough. The amount and level of exercise sounds like a lot, and it is. Still, the trick is to find a routine that works with your schedule, then stick with it. Make sure you like the exercise you're doing and the place you do it. For example, if you don't like gyms or being around people, then a group exercise class probably isn't for you.
- Reduced breast cancer risk was seen no matter when in her life a woman started her exercise routine. It's NEVER too late to start exercising.
- Women who had a family history of breast cancer did not seem to benefit from the protective effects of strenuous exercise. But it's very likely that these women got other health benefits from exercise.
To learn more about the role of exercise and a healthy lifestyle in lowering your risk of breast cancer visit breastcancer.org's Risk Factors You Can Control section.