The following lifestyle changes have been studied in connection
with breast cancer. Exercise and prevention Girls who engage in
a significant amount of exercise have been reported to be less
likely to get breast cancer as adults.1 Although some doctors
speculate that exercise in preadolescent girls might reduce the
risk of eventually getting breast cancer by reducing the number
of menstrual cycles and therefore exposure to estrogen, these
effects may occur only in girls engaging in very strenuous
exercise.2 Most,3, 4 but not all,5 studies find that adult women
who exercise are less likely to get breast cancer. Women who
exercise have also been reported to have a reduced risk of high-
risk mammography patterns compared with inactive women.6
Exercise in adulthood might help protect against breast cancer
by lowering blood levels of estrogen or by helping maintain
ideal body weight. In addition to the preventive effects of
exercise, aerobic exercise has been reported to reduce
depression and anxiety in women alrea