A number of previous studies have suggested that fish oil supplements may play a role in preventing chronic disease.  Emily White, from Fred Hutchinson Cancer Research Center (Washington, USA), and colleagues surveyed 35,016 postmenopausal women who did not have a history of breast cancer on their use of non-vitamin, non-mineral "specialty" supplements and tracked the incidence of breast cancer during a six-year follow-up period. The team found that those women who regularly used fish oil supplements, which contain high levels of omega-3 fatty acids, had a 32% reduced risk of breast cancer, with the risk reduction limited to invasive ductal breast cancer, the most common type of the disease.  Writing that: “Fish oil may be inversely associated with breast cancer risk,” the researchers urge that: “Fish oil is a potential candidate for chemoprevention studies.”