Studies have shown that being physically active may reduce
a woman's risk for developing breast cancer, although many
questions have yet to be answered. For example, these studies
have hinted that very high activity levels may not be as beneficial
for reducing breast cancer risk as moderate activity levels.
In southern Germany, approximately 350 women with premenopausal
breast cancer and nearly 900 women free of cancer participated
in a study in which they reported on multiple types of activity,
between the ages of 12-19 and 20-30. Activities included different
sports; household tasks; occupational activities; walking;
and cycling.
Moderate
activity levels reduced breast cancer risk the most (32%),
with very high activity levels actually increasing risk, compared
to inactive women. Women who reported bicycling the most (the
equivalent of at least three hours per week at moderate intensity)
reduced their risk for breast cancer by 34% in this study
in the American Journal of Epidemiology. Being active
reduced cancer risk regardless of sports participation.
The authors conclude that moderate activity may effectively
reduce breast cancer risk, whereas high activity does not,
because while the former may strengthen the immune system,
the latter may depress it. Most women need not worry about
being overly active, though, as this only applies to a small
percentage of the most active women. A fairly vigorous workout
several times per week, especially riding a bicycle, may be
a good way to reduce your risk for breast cancer.
Reference:
Steindorf K, Schmidt M, et al. Case-control study of physical
activity and breast cancer risk among premenopausal women
in Germany. American Journal of Epidemiology 2003:157(2),
pp. 121-130.
Women's health topics appear at https://www.chiroweb.com/find/archives/women.
|