In a study involving nurses between the ages of 30-55 years old researchers found those who exercised at least seven hours per week reduced their risk by twenty percent, reports CBS News Correspondent Dr. Emily Senay.
Brisk walking was the most popular form of exercise and was found to be as beneficial as strenuous exercise. Those who exercised two to four hours per week had a ten percent risk reduction.
Women who exercise are typically leaner and have lower levels of estrogen. High levels of estrogen stimulate the growth of breast cells and increase the chances of cancerous cell growth.
These findings are consistent with other studies that show the effects of regular exercise are beneficial. Previous analysis' have shown exercise can also help lower the risk of diseases such as colon cancer, heart disease, and diabetes.