Adult weight gain a risk factor for breast cancer

In research carried out among women who did not take hormone replacement therapy after menopause, women who gained weight as they aged were found to have a higher risk of breast cancer.

It's already known that obese women have more risk of the disease because of the accumulation of oestrogen in fat tissue. In this new study, researchers used postmenopausal women participating in the National Institutes of Health-AARP Diet and Health Study. Their body weights were first measured in 1996. By the end of 2000, 2111 of the 99039 women in the study had developed breast cancer. Gaining weight was linked to a raised risk of developing breast cancer in compared to women whose weight remained stable.