Whether or not women breast-feed could impact their risk for breast cancer.

Researchers at the Fred Hutchinson Cancer Research Center wanted to know whether reproductive factors influenced the risk for certain types of breast cancer.

They studied over one thousand women with the disease, and compared them to women without breast cancer.

They found women who breast-fed for six months or longer had a lower risk for a type of disease called luminal cancer.

Women who started menopause and used certain hormone therapies had an increased risk for this form of the disease.

In other medical news…

A protein involved in bone growth may also spur the development of "good" fat.

Researchers at Joslin Diabetes Center studied a protein that is known to induce bone growth.

They found, when injected in mice, the protein also triggered the development of brown fat.

Brown fat burns calories by generating heat, and is known to play a role in preventing obesity.

Most adults lose brown fat cells as they age.

The mice that got the injection gained less weight compared to those that did not.

Researchers hope to use this information to develop treatments for people with a genetic risk for obesity.