Wild salmon is an excellent source of omega-3 fatty acids. It is far superior to the more common and less expensive farm-raised salmon, which can contain cancer-causing PCBs. Omega-3s "thin" the blood and lower blood pressure and harmful LDL cholesterol levels. People with the highest levels of these fats in their blood were 68 percent less likely to suffer a fatal heart attack than those with the lowest levels. Look for salmon that's clearly labeled as "wild," or purchase fish from a reliable seafood purveyor.