A recent study has found that omega-3 fatty acids may improve colon health and help fight colorectal cancer. Yet, when aspirin is taken concurrently, the omega-3's demonstrate no benefit.
In the study, researchers analyzed blood samples collected from the Physicians' Health Study. Specifically, omega-3 and omega-6 fatty acid levels were analyzed in 178 men who developed colorectal cancer and compared to 282 men without colorectal cancer.
The researchers found that for men taking aspirin, Omega-3 fatty acid blood levels did not significantly decrease colorectal cancer risk, yet significant risk reductions were seen in men not taking aspirin. Specifically, those with the highest 25% of blood levels of omega-3's had a 40% reduced risk of colorectal cancer compared to those with the lowest 25% of blood levels of omega-3’s.
They found almost 10 percent ate fish less than once a week, 31 percent ate it less than two times a week, 48 percent ate fish less than five times a week, and about 11 percent ate it five times or more a week. Since only blood levels of omega-3 fatty acids were measured, no intakes of O3FA’s could be recommended by the researchers for colon health. Nevertheless, “blood levels of long-chain n-3 fatty acids were associated with decreased risk of colorectal cancer among men not using aspirin.”
Hall MN. Blood Levels of Long-Chain Polyunsaturated Fatty Acids, Aspirin, and the Risk of Colorectal Cancer. Cancer Epidemiol Biomarkers Prev 2007 16: 314-321.
Related publication from the same study: Omega-3 Fish Oil Reduces Colon Cancer Risk by 40%.