Ômega 3 reduz câncer de próstata

Atenção aos aficionados por produtos naturais e aos que desacreditam deles: consumir a partir de 500mg de ácidos graxos ômega 3 na dieta ou suplementos reduz a incidência de câncer de próstata e de câncer de próstata avançado. Foi o que um estudo publicado numa das mais prestigiadas revistas de cancerologia do mundo concluiu. A notícia completa segue abaixo:

NEW YORK (Reuters Health) Mar 25 - Results of a case-control study suggest that a high intake of long-chain omega-3 fatty acids protects against advanced prostate cancer, and this effect may be modified by a genetic variant of COX-2, a key enzyme in fatty acid metabolism and inflammation.

"Previous research has shown protection (by omega-3 fatty acids) against prostate cancer, but this is one of the first studies to show protection against advanced prostate cancer and interaction with COX-2," Dr. John S. Witte of the University of California, San Francisco noted in a statement from the American Association for Cancer Research (AACR)

Dr. Witte and colleagues studied 466 men diagnosed with aggressive prostate cancer and 478 age- and ethnicity-matched controls. They assessed diet using a food frequency questionnaire and genotyped the men for nine COX-2 single nucleotide polymorphisms.

In an online issue of the AACR journal Clinical Cancer Research, the researchers report that increasing intake of long-chain omega-3 fatty acids was strongly associated with a decreased risk of aggressive prostate cancer.

Men in the highest quartiles of long chain omega-3 fatty acid intake had a 63 percent reduced risk of aggressive prostate cancer (odds ratio, 0.37) compared to men in the lowest quartile.

"Importantly," Dr. Witte and colleagues say, this protective effect was even stronger in men who carried the COX-2 single nucleotide polymorphism rs4647310, a risk factor for prostate cancer.

Specifically, men with low intake of long-chain omega-3 fatty acids and this particular variant had a more than fivefold increased risk of advanced prostate cancer (odds ratio, 5.49), whereas men with high intake of omega-3 fatty acids had a substantially reduced risk, even if they carried the COX-2 rs4647310 variant.

In other words, the increased risk of prostate cancer associated with the COX-2 rs4647310 variant was "essentially reversed by increasing omega-3 fatty acid intake by a half a gram per day," Dr. Witte said.

"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," he added.

Clin Cancer Res 2009;15:7.