Omega-3 fatty acids fight inflammation, which may explain why they seems to lower the risk of breast cancer in postmenopausal women who are obese. Data from normal-weight women may have obscured the results, researchers say. These women have less inflammation than heavier women, and are therefore less likely to benefit from anti-inflammatory omega-3s.
Published in the journal Cancer Prevention Research, the study included 266 healthy postmenopausal women with high breast density detected by routine mammograms. The women either received no treatment, the antiestrogen drug Raloxifene, a prescription omega-3 drug, or a combination of the two drugs. At the conclusion of the two-year study, the researchers found that increasing levels of omega-3 in the blood were associated with reduced breast density—but only in women with a body mass index above 29, bordering on obesity. “The higher the breast density, the more likely the woman will develop breast cancer,” Andrea Manni says.