PT writers wanted
profood - food ingredients supplier
shopseek shop dir.
infoplus web dir.
||Last Updated: Nov 12th, 2006 - 20:38:00
By Diana Simms
Eating just one portion of salmon per week may decrease the risk of prostate cancer by about 43 percent, according to a new study be Swedish researchers, who say the effect is mainly due to the omega-3 fatty acids in the fish.
The study is one more reason why consumers need to be aware of the role omega-3 fatty acids play in ensuring better health. Omega-3 fatty acids are thought to benefit people with heart disease, joint pain and even prevent some cancers.
The Swedish researchers led by Maria Hedelin from the Karolinska Institutet in Stockholm report that genetics may play a big part in the development of cancer and also determine how fish oil benefits the body.
For the study, Maria Hedelin and colleagues analyzed and compared the dietary intakes of fish among 1,499 men with prostate cancer and 1,130 healthy men. They also took into consideration the genetic variations in cyclooxygenase (COX)-2, which plays a vital part in fatty acid metabolism and inflammation.
The researchers said that men who ate salmon-type fatty fish at least once a week had a 43 percent reduced risk of prostate cancer as compared with men who never ate any type of fish. The researchers also found that consuming fatty fish on a regular basis increased the interaction in a single nucleotide polymorphisms (SNP) in a COX-2 gene.
This gene is present in 60 percent of the population. Men who carried the variant gene had a 72 percent reduced risk of prostate cancer than those who did not carry the variant. "Frequent consumption of fatty fish and marine fatty acids appears to reduce the risk of prostate cancer, and this association is modified by genetic variation in the COX-2 gene," said Hedelin.
The researchers say that the most probable mechanism is that the gene appears to control the results when omega 3 and omega 6 fatty acids compete for hormone-like chemicals called prostaglandins. When associated with omega-3 fatty acids, the prostaglandins are anti-inflammatory, while with omega-6 they appear to be pro-inflammatory, the researchers reported.
Other studies seem to support this conclusion. A published in March in the British Journal of Cancer suggested that a metabolite of the omega-6 fatty acid, arachidonic acid (AA), prostaglandin E2 was involved in the spread of prostate cancer to the bone marrow. But with the presence of EPA and DHA, omega-3 fatty acids found in fatty fish, this process was halted.
A second study in August in the journal Clinical Cancer Research found that when the ratio of omega-3 to omega-6 increased in the diet of mice, there was a 22 percent reduction in prostate cancer growth as compared to mice with higher percentage of omega-6 fatty acids.
In the present study, which appears online ahead of print in the International Journal of Cancer, researchers determined that a gene affects the effect of omega-3 fatty acids on prostate cancer cells.
"This study shows that there is an interaction between dietary factors and our genes, but it's always hard to say what role the genes play," Hedelin concluded. "Omega-3 fatty acids can still be good for men who don't carry this gene variant in completely different ways."
Prostate cancer leads to 200,000 deaths worldwide annually. The incidence of the cancer has exploded over the last decade, particularly in the rich countries. In the U.S., about 190,000 men are diagnosed with the disease every year compared to 27,000 men in the UK and 18,000 men in Canada.
© 2004-2005 by foodconsumer.org unless otherwise specified
Top of Page