Regular exercise can lower the risk of breast cancer in African American women, according to a recent study.
For the study, researchers used data from the Black Women's Health Study (BWHS), which followed more than 44,000 African American women over the span of 16 years and observed whether they developed breast cancer. The data also contained information about the participants' exercise habits, such as time spent exercising per week and type of exercise.
After a thorough analysis, researchers found that women who exercised for seven or more hours each week were 25 percent less likely to develop breast cancer, compared to those who exercised less than one hour each week. Similar benefits were also observed in women who indulged in brisk walking or moderate-intensity exercises, though not to the extent seen in the former case.
"Although expert review panels have accepted a link between physical exercise and breast cancer incidence, most study participants have been white women. This is the first large-scale study to support that vigorous exercise may decrease incidence of breast cancer in African American women," said Lynn Rosenberg, ScD, professor of Epidemiology at Boston University School of Public Health.
A study conducted earlier this year reported similar findings. The authors of the study stated exercise reduces women's risk of breast cancer, no matter what kind of exercise they do, how old they are, how much they weigh, or when they get started.
According to national activity guidelines, a good goal is to exercise at least 30 minutes a day, most days of the week. To get the optimal benefit, however, experts say to aim for about an hour a day. Moderate-intensity activities such as brisk walking may be sufficient, although there is more benefit associated with increased intensity.
The current study was published online in the journal Cancer Epidemiology, Biomarkers & Prevention. The project was funded by the National Cancer Institute.
