FRIDAY, Feb. 17, 2012 (HealthDay News) -- Eating at least three servings of fish a week may reduce women's risk of developing some types of colon polyps, according to a new study.
Colon polyps are small growths on the intestinal lining that may develop into cancer. Previous research has suggested a link between inflammation and formation of colon polyps.
Omega-3 fats in fish may reduce inflammation and help protect against the development of colon polyps, according to the researchers at the Vanderbilt-Ingram Cancer Center in Nashville, Tenn..
Their study of more than 5,300 people found that women who ate at least three servings of fish a week were 33 percent less likely to develop colon polyps, and also had lower levels of an inflammation-related hormone called prostaglandin E2.
"That was the aspect of the study we were particularly excited about because prostaglandin E2 is known to be associated with adenomas or polyps in colorectal cancers," first author Dr. Harvey Murff, an associate professor of medicine, said in a Vanderbilt University Medical Center news release.
Fish oil appears to have the same beneficial effect as aspirin in reducing inflammation, he said.
The researchers were surprised to find that eating fish reduced the risk of colon polyps in women, but not in men.
"The difference between men and women may be linked to their background diet. Even though men are eating more omega-3 fatty acids they may also be eating more omega-6 fatty acids and that may be blunting the effect," Murff said. Omega-6 fatty acids are found in meats, grains and seed oils, including corn oil.
Types of fish with high levels of the protective omega-3 fatty acids include tuna, salmon and sardines.
The study was published online in the American Journal of Clinical Nutrition.
While the study found an association between fish and a lowered chance of having polyps, it did not prove that a diet rich in fish is responsible for the reduction. Other factors could play a role.
The American Society of Colon and Rectal Surgeons has more about colorectal polyps.