Research suggests that exercise is linked to a lower breast cancer risk. However, studies have not investigated if there is a link between exercise and mammographic breast density. Dense breast tissue is associated with breast abnormalities such as benign cysts or breast cancer. Dense tissue can also affect mammographic results and cause false negative mammograms. Now for the first time, research reports that exercise is not linked to breast tissue density.
The study, published in the International Journal of Cancer, investigated the association of physical activity levels and mammographic breast density in women. Researchers from the University of Southern California analyzed data from the Women's Contraceptive and Reproductive Experiences Study including 375 white and African-American women who did not have breast cancer at the beginning of the study. Surveys obtained from the participants were analyzed for their exercise habits during five time periods including menarche (first menstruation) to mammogram screening, the first 3 and 10 years after menarche, the most recent 10 years and the 3 years prior to mammogram screening.
The researchers found that there was no evidence indicating exercise increased breast tissue density. However, among younger women there was a slight positive association between lifetime exercise and higher tissue density. There was also a slight positive association between recent physical activity and density in younger and older women, but this association decreased after adjusting for body mass index. Furthermore, among women younger than 50 years, there was a protective effect of strenuous exercise (a lower breast density) in the first 3 years after first menstruation.
"Our results suggest that physical activity is not a strong predictor of mammographic density," the study authors conclude.
REFERENCES:
1. Siozon CC et al. The association between recreational physical activity and mammographic density. International Journal of Cancer 2006; 119(7):1695-1701.
Posted by Elaine Gavalas on October 31, 2006 03:21 PM
