STOCKHOLM, SWEDEN. Several studies have shown an inverse relationship between blood levels of fish oils and the risk of prostate cancer. (Fish oils contain eicosapentaenoic acid and docosahexaenoic acid [EPA and DHA, respectfully.]) A study just completed by medical researchers at the Karolinska Institute confirms this association.
The Swedish study involved 3136 pairs of male twins born between 1886 and 1925. The participants completed food frequency questionnaires in 1961 and 1967 and were then followed up for 30 years. By December 31, 1997 the researchers had recorded 466 diagnoses of prostate cancer (340 fatal ones). The average age of diagnosis was 76.7 years. After adjusting for other known risk factors the researchers conclude that men who never eat fish have a two- to three-fold higher risk of prostate cancer than do men who eat moderate to high amounts. The researchers emphasize that only fatty fish such as salmon, herring and mackerel, which contain high amounts of omega-3 fatty acids (EPA and DHA), would be expected to be beneficial.
Terry, Paul, et al. Fatty fish consumption and risk of prostate cancer. The Lancet, Vol. 357, June 2, 2001, pp. 1764-66 (research letter)