Fish Oil May Reduce Risk of Common Breast Cancer
You may have heard about the benefits of fish oil from previous studies, but new research results lend additional strong support to the use of this supplement in reducing the risk of breast cancer. The reduced risk in the latest study was limited to the most common type of the disease, invasive ductal breast cancer.
Breast cancer types are classified based on where they begin, whether in the ducts or lobules, the organs responsible for breast milk production. The National Breast Cancer Foundation lists seven different types of breast cancer, and invasive (or infiltrating) ductal carcinoma is the most common, representing 78 percent of all malignancies. Other types of breast cancer include ductal carcinoma in situ, medullary carcinoma, infiltrating lobular carcinoma, tubular carcinoma, mucinous carcinoma, and inflammatory breast cancer.
The most recent study, which was conducted by experts at the Fred Hutchinson Cancer Research Center in Seattle, Washington, involved the use of a 24-page questionnaire completed by 35,016 postmenopausal women who were part of the Vitamins and Lifestyle (VITAL) cohort study. None of the women had a history of breast cancer. The women answered questions about their use of supplements beyond vitamins and minerals.
After six years of follow-up, the researchers identified 880 women who had been diagnosed with breast cancer. When they evaluated the women’s use of supplements, they found that regular use of fish oil supplements was associated with a 32 percent reduced risk of breast cancer, which was restricted to invasive ductal carcinoma. None of the other supplements used by the women were found to be linked with breast cancer risk.
Fish oil is a rich source of the omega-3 fatty acids EPA (eicosapentoaenoic acid) and DHA (docosahexaenoic acid), which have been studied extensively for prevention and treatment of various diseases. Fish oil has been shown, for example, to reduce the risk of heart disease, relieve symptoms of arthritis and other inflammatory conditions, help prevent macular degeneration, fight depression, and even help infertile men.
The results of this latest study are the first to show a link between the use of fish oil and a reduction in breast cancer. Why fish oil supplements provide this benefit is not known, although the study’s lead author, Emily White, PhD, a member of the public health sciences division, speculated that “it may be that the amount of omega-3 fatty acids in fish oil supplements are higher than most people would typically get from their diet.”
Further studies are necessary before experts go so far as to recommend that women take fish oil to reduce their risk of breast cancer. White noted that “without confirming studies specifically addressing this, we should not draw any conclusions about a causal relationship.” Professor of nutrition and epidemiology at the Harvard School of Public Health, Edward Giovannucci, MD, ScD, agreed. He said that “as the studies confirm each other, we can start to make recommendations.”
American Association for Cancer Research news release, July 8, 2010
National Breast Cancer Foundation