Vis
effectief tegen kanker*
Uit een studie onder een kleine duizend mannen blijkt dat het regelmatig eten van vette
vis, rijk aan omega-3 vetzuren zoals makreel, haring en zalm de kans op prostaatkanker wel met 60% kan verminderen. Verder kan door het eten van vette vis het effect van een aangeboren genetische aanleg voor de ontwikkeling van een agressieve vorm van prostaatkanker teniet gedaan worden. 1-3 keer per maand vette vis eten reduceert de kans op prostaatkanker met 36%, meer dan 1 keer per week doet die kans met 57% dalen. Omega-3 vetzuren hebben ook een enorm effect op een gevaarlijke variant van het COX-2 gen. Mannen met deze genvariant hebben meer dan vijf keer meer kans op een agressieve vorm van prostaatkanker. Regelmatig
vette vis eten (iedere dag 0,5 gram omega-3
vetzuren) doet het effect van dit gevaarlijke gen volledig teniet.
Fish oil 'could cut cancer risk'
Fish oil may protect men against potentially deadly aggressive prostate cancer, a study has suggested.
Researchers found that a high intake of omega-3 fatty acids, found in oily fish such as herring, salmon and mackerel, could reduce the risk of developing the disease by about 60%. It also reversed the effect of an inherited gene which is known to increase the risk of aggressive prostate cancer.
The study compared the diets of 466 men diagnosed with the disease and 478 healthy men. A diet questionnaire was used to assess participants eating habits, focusing on how often the men ate fish or shellfish.
Men who ate "dark" oily fish, rich in omega-3, one to three times per month had a 36% lower risk of prostate cancer than those who never ate dark fish. Eating oily fish more than once a week had an even bigger protective effect, leading to a 57% reduction in risk.
A similar trend was seen for different levels of shellfish intake. Shellfish also contains omega-3 fatty acids. Omega-3 intake also had a major impact on the effect of a hazardous variant of the COX-2 gene, which promotes inflammation and is known to be linked to prostate cancer.
Men with the variant have a more than five-fold increased risk of aggressive prostate cancer. But a high consumption of oily fish effectively wiped out this risk factor.
Study leader Professor John Witte, from the University of California in San Francisco, said: "The COX-2 increased risk of disease was essentially reversed by increasing omega-3 fatty acid intake by a half a gram per day.
"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."
Aggressive cancer was defined as having a PSA (prostate specific antigen) blood test result of 10 or higher and a Gleason score of seven or above. Gleason score, ranging from one to 10, is a measure of prostate cancer aggressiveness. Omega-3 fatty acids may help to prevent prostate cancer by combating inflammation, the scientists believe.
There is increasing evidence that inflammation influences cancer risk. Inflammation, which is an inappropriate immune system response, can be affected by diet, bacterial and viral infections, and genetic make-up. The findings were reported in the journal Clinical Cancer Research.
(April
2009)
