Do you know your omega-3 index?

New research suggests that this number—a measurement of the body’s levels of the most heart-healthy omega-3 fatty acids—may be an important predictor of both heart disease and sudden cardiac death. Unfortunately, not enough people know their omega-3 index to make use of it.

Researchers at St. Luke’s MidAmerica Heart Institute in Kansas City, Missouri, reported that subjects with an omega-3 index of 8 percent to 10 percent reduced their risk of coronary artery disease by 40 percent and of sudden cardiac death by 90 percent. Subjects with an omega-3 index of 4 percent or less had the highest risk for heart disease (Preventive Medicine, 2004, vol. 39, no. 1). The omega-3 index is determined through a blood test; check whether your doctor offers this test.

Luckily for fish lovers, the two most beneficial omega-3 fatty acids, EPA and DHA, are found primarily in oily fish, such as tuna, salmon, and mackerel, or from supplements containing these oils. Vegetarians may be able to get omega-3 fats from fresh seaweed or ground flaxseed.