March 25, 2009

Omega-3 cuts advanced prostate cancer risk

Omega-3 fatty acids appear protective against advanced prostate cancer and this effect may be modified by a genetic variant, U.S. researchers said.

Previous research has shown protection against prostate cancer but this is one of the first studies to show protection against advanced prostate cancer and interaction with the COX-2 gene, John S. Witte of the University of California San Francisco said in a statement.

The researchers performed a case-control analysis of 466 men diagnosed with aggressive prostate cancer and 478 healthy men. Diet was assessed by a food frequency questionnaire and researchers genotyped nine COX-2 single nucleotide polymorphisms.

Researchers divided omega-3 fatty acid -- found in fatty fish like salmon and sardines -- intake into four groups based on quartiles of intake.

Men who consumed the highest amount of long chain omega-3 fatty acids had a 63 percent reduced risk of aggressive prostate cancer compared to men with the lowest amount of long chain omega-3 fatty acids.

The researchers then assessed the effect of omega-3 fatty acid among men with the variant rs4647310 in COX-2, a known inflammatory gene.

The study, published in the Clinical Cancer Research, found men with low long chain omega-3 fatty acid intake and this variant had a more than five-fold increased risk of advanced prostate cancer but men with high intake of omega-3 fatty acids had a substantially reduced risk, even if they carried the COX-2 variant.