Losing excess weight—and keeping it off—may help women over age 50 lower their risk of breast cancer, suggests an observational study in the Journal of the National Cancer Institute, which looked at data from more than 180,000 women ages 50 and older.
Compared to women whose weight stayed stable over the study period (about 10 years), those who lost 4 to 10 pounds in the first five years and maintained the loss had a 13 percent lower risk of developing breast cancer; those who lost 10 to 20 pounds, a 16 percent lower risk; and those who lost 20-plus pounds, a 26 percent lower risk. Women who lost 20 or more pounds but gained some of the weight back were also less likely to develop breast cancer than women who lost no weight.
Being overweight or obese is a known risk factor for breast cancer after menopause. The authors noted, however, that the risk reduction from weight loss was seen only in women not taking postmenopausal hormone therapy. (There was no relationship, good or bad, between weight changes and cancer risk in those taking hormones.)
This article first appeared in the UC Berkeley Wellness Letter.
Also see Breast Cancer Prevention Update.