Health news from around the globe.

Researchers at the University of Colorado reported that regular exercise can help fight the negative effects of stress on the brain. In studies involving rats, the investigators found that rodents which ran for exercise released less norepinephrine (a stress hormone) than sedentary rats. In addition, rats that exercised before exposure to stress recovered more quickly from infections with E. coli bacteria.

In a major study published in the Archives of Internal Medicine, researchers reported that exercise may reduce the risk of breast cancer. The investigators analyzed questionnaires from 121,701 women, ages 30 to 55, nationwide. They discovered that women who exercised a minimum of one hour every day decreased their chances of getting breast cancer by 20 percent. Researchers believe exercise lowers the level of estrogen, which has been found to stimulate breast cell growth, increasing the chances of cancer.

A study involving more than 70,000 women revealed that exercise lessens the chance of developing adult-onset diabetes. Published in the Journal of American Medical Medicine, the study showed that moderate to vigorous exercise, including brisk walking, was enough to lower the risk by 46 percent.