Diet

Diet and Breast Cancer: Increased Risk With Weight Gain

Among post-menopausal women, the age group most susceptible to breast cancer, the evidence continues to implicate weight gain as a risk factor for breast cancer. In one recent study, obese women in their post-childbearing years had a 3.2 times greater chance of breast cancer than women of a healthy weight. The researchers took into account several other factors that affect breast cancer risk, including a woman’s age, age at menopause, family history of breast cancer, and history of childbearing.

Among breast cancer survivors, researchers are beginning to associate excess weight with an increased risk of recurrence and mortality, says Colleen Doyle, MS, RD, director of nutrition and physical activity for the American Cancer Society.

It’s tempting to think that a low-fat or vegetable-filled diet would reduce breast cancer, but the association between these diets and breast cancer prevention really hasn’t panned out, Doyle explains. In one study that showed a connection between a low-fat diet and reduced risk of breast cancer recurrence, the study participants also lost weight. “So it wasn’t really clear — is it effect from low fat or weight loss? I tend to think it’s probably weight loss because dietary fats have been discounted as a prevention factor for breast cancer,” Doyle says.