Body Size & Breast Cancer Risk in Young Women

by Diane Lofshult

Strange as it may seem, higher body mass index (BMI) has been associated with reduced risk of breast cancer in premenopausal women. Researchers recently conducted a longitudinal study of 113,130 young women to determine the mechanisms underlying this

“We observed a significant linear inverse trend between current BMI and breast cancer that was not explained by menstrual cycle characteristics or infertility due to an ovulation disorder. We found BMI at age 18 years is the strongest predictor of breast cancer incidence.

“Body size during the early phases of adult life seems to be particularly important in the development of premenopausal cancer,” the researchers concluded. Their findings were published in the Archives of Internal Medicine (2006; 166 [21], 2395–2402).

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