In two separate recent studies published in the American Journal of Clinical Nutrition, scientists found that Omega-3s protected against cognitive decline in a group of older men at risk for cardiovascular disease. At the end of the five-year study, those taking supplements had less cognitive decline than people who didn’t.

The other study was conducted at many sites throughout the United States. One study measured plasma fatty acid levels in a group of 2,251 men living in Minnesota between 1990 and 1992 and from 1996 to 1998. During that time, investigators at the University of Minnesota, in collaboration with colleagues at the University of North Carolina and the Johns Hopkins University School of Public Health in Maryland, conducted three neuropsychological tests to study attention and memory.

Again, those taking omega-3 fatty acids had less risk of “global cognitive decline,” the authors reported. What’s more, a number of cardiovascular factors were pushed in the direction of better health.

Omega-3 fatty acids help lower blood pressure and increase the flexibility of the vascular wall. High blood pressure can make the wall more rigid. Omega-3 fatty acids can also penetrate red blood cells, making them more flexible and better able to get through narrowed arteries.

There are more cardiovascular benefits, according to a study published in Lancet. Japanese researchers at Kobe University studied 18,000 people with high cholesterol and some kind of unhealthy heart history. Everyone was prescribed statins, the cholesterol-lowering agents, and half of them also received omega-3 fatty acids while the others swallowed a placebo.

They were followed for more than four years, at which time the scientists found 20 percent fewer cardiac events, including heart attacks, in those on 12 grams of fish oil a day.

Omega-3’s most potent effect is as an anti-inflammatory agent. It is now being used in a number of inflammatory disorders, including arthritis, lupus and some cancers. Studies have shown that Omega-3 regulates genes involved in inflammation. Human genes have co-evolved with the foods we have eaten for centuries,” Sears said.