The association between fish oils and endometrial cancer took an unexpected turn in a study from the Ohio State University College of Medicine. Researchers studied 22,494 women between the ages of 50- and 76-years-old and their self-reported intake of the omega-3s, DHA and EPA, from seafood or supplements. After nine years, there were 263 cases of endometrial cancer. Women who consumed the most omega-3s showed a 79% increased risk for cancer compared to women who consumed the least omega-3s. However, when the women were stratified by body mass index (BMI), this increased association was found only in those who were overweight or obese. Healthy weight women who consumed omega-3-rich diets showed a significant reduction in endometrial cancer risk.
Brasky T, Neuhouser M, Cohn D, et al: Association of long-chain omega-3 fatty acids and fish intake with endometrial cancer risk in the VITamins and Lifestyle cohort. American Journal of Clinical Nutrition 2014;99:599-608.