Vigorous exercise of more than 2 hours per week reduces the risk of developing breast cancer in postmenopausal African-American women by 64%, compared to women of the same race who do not exercise, according to researchers at Georgetown Lombardi Comprehensive Cancer Center.
“People often want to know what they can do to reduce their risk of disease, and we have found that just two or more hours of vigorous activity per week can made a difference in one’s risk of developing breast cancer,” lead researcher Vanessa Sheppard, PhD, a cancer control scientist and assistant professor in the department of oncology at the Lombardi Comprehensive Cancer Center, stated in a press release.
In this study, more than 2 hours of aerobics, running or similar activity in the span of a week counted as vigorous activity.
“We also know from other studies that being physically active can have benefits in other diseases that occur at high rates in African-American women, such as diabetes and hypertension,” Sheppard stated. “Four out of five African-American women are either overweight or obese, and disease control is a particularly important issue for them.”
The researchers identified 97 recently diagnosed African-American breast cancer patients in the Washington, D.C., area and matched them with 102 African-American women without breast cancer. Participants filled out a questionnaire about exercise routines which were then analyzed and compared.
Women who exercised vigorously for more than 2 hours a week in the past year had a 64% reduced risk of breast cancer compared to women who did not exercise. Women who engaged in moderate exercise, like walking, had a 17% reduced risk, compared to women who were sedentary.
After evaluating those who were pre- and postmenopausal, they found that vigorous exercise only significantly benefitted postmenopausal women — they had a 62% reduction in risk.
“I was surprised that we did not find a significant effect in premenopausal women, but it may be because we need a larger sample,” Sheppard stated.
However, when the researchers examined the effect of total physical activity, which combined walking with vigorous activity of 2 or more hours per week, they saw significant gains for both premenopausal and postmenopausal women.
“We suggest that our findings, while promising, should be interpreted with caution. This is a pilot study and a larger, more rigorous study is needed to precisely quantify the effect of exercise on development of breast cancer,” Sheppard stated. “I think it is fair to conclude that if African American women exercise they can help take charge of their health.”