A new (March 24th) report in Clinical Cancer Research, a journal of the American Association for Cancer Research, shows that Omega-3 fatty acids appear protective against advanced prostate cancer.
Dr. John S. Witte, Ph.D., professor of epidemiology and biostatistics at the University of California San Francisco, says that previous research has shown protection against prostate cancer, but that this is one of the first studies to show protection against advanced prostate cancer.
For this study, researchers performed a case-control analysis of 466 men diagnosed with aggressive prostate cancer and 478 healthy men. Their diet was assessed by a food frequency questionnaire and researchers did a genotype study to see which of the men had a gene that accounts for a very aggressive form of cancer.
Researchers divided omega-3 fatty acid intake into four groups. Men who consumed the highest amount of omega-3 fatty acids had a 63 percent reduced risk of aggressive prostate cancer compared to men with the lowest amount of omega-3 fatty acids.
Then, researchers assessed the effect of omega-3 fatty acid among men with the variant gene that causes the aggressive cancer. Men with low omega-3 fatty acid intake and this variant had a more than five-fold increased risk of advanced prostate cancer. Interestingly, men with high intake of omega-3 fatty acids had a substantially reduced risk, even if they carried the variant gene.
“The increased risk of disease was essentially reversed by increasing omega-3 fatty acid intake by a half a gram per day,” said Witte. “If you want to think of the overall inverse association in terms of fish, where omega-3 fatty acids are commonly derived, the strongest effect was seen from eating dark fish such as salmon one or more times per week.”