Regularly eating omega-3-rich fish—about twice a week—boosts mind and body:  

• Cardiovascular health. “The best-established benefit is a 35 percent reduction in cardiac death from eating one to two servings a week compared to not regularly eating fish,” says Harvard cardiologist Dariush Mozaffarian, M.D. That intake is also linked to a lower risk of nonfatal heart attacks, strokes, irregular heartbeat, plaque buildup and high blood pressure.

• The brain. “Eating two or more servings of fish a week reduces the risk of dementia by nearly half,” says Ernst Schaefer, M.D., of the Jean Mayer USDA Human Nutrition Research Center on Aging. His conclusion comes after tracking 900 older Americans for nearly 10 years. There’s also some evidence that a high intake of omega-3s can sustain memory and better manage depression.

• Vision. An analysis, published in June’s Archives of Ophthalmology, of nine previous studies tracking 89,000 older people finds that eating fish regularly was associated with a 38 percent lower risk of age-related macular degeneration, the leading cause of blindness in the elderly.  

• Cancer. Eating fatty fish a few times a month was linked to a 74 percent lower risk of kidney cancer, according to another study by Swedish researchers published in the Journal of the American Medical Association in 2006. Other evidence suggests a possible lower risk of cancers of the breast, colon and prostate, but more research is needed.