Fish oil may not help prevent swine flu

Bu David Liu (davidl@foodconsumer.org)

Taking dietary fish oil may not be the way to help prevent swine flu, a new study suggests.

The study found dietary fish oil impaired the immune response to influenza infection leading to increased morbidity and mortality.

At the time the world comes under the threat from swine flu, Nicole M.J. Schwerbrock at the University of North Carolina at Chapel Hill tested the effect of dietary fish oils, rich in n-3 PUFA including eicosapentaenoic acid and docosahexaenoic acid on the immune response to influenza infection in mice.

Dietary fish oils have been shown to have antiinflammatory properties, which are beneficial during a chronic inflammatory illness.  But the same properties can suppress the inflammatory response that is required to combat acute viral infection, the authors said in their report published in the Sept 2009 issue of Clinical Nutrition.

For the study, Schwerbrock and colleagues fed mice for two weeks either fish oil spiked diet or corn oil spiked diet as controls to compare the lung pathology and immune function in both groups. In the study group, 4 grams of fish oil and 1 gram of corn oil was used in 100 grams of diet.

The researchers found fish oil fed mice had lower lung inflammation compared to the controls, but fish oil group were at 40 percent  higher risk of death, had 70 percent higher lung viral load by the 7th day of infection, and had a prolonged recovery period after infection.

But more studies are needed to confirm that taking fish oil may harm the imunity in humans against swine flu.