While research has shown that the omega-3 fatty acids in fish may help boost memory, lower the risk of Alzheimer’s, and decrease the chance of heart attack, researchers knew little about how these essential fatty acids influence overall longevity.
This was the inspiration behind a new study from the Harvard School of Public Health and the University of Washington, in which researchers tried to figure out whether the effects of fish oil on the heart could translate to a longer life span. The results were reported in the journal Annals of Internal Medicine.
For the study, the researchers reviewed 16 years of data from the long-term Cardiovascular Health Study by the National Heart, Lung and Blood Institute. This included information on 2,700 healthy adults aged 65 and older who did not take fish oil supplements, and who participated in regular physical exams, diagnostic tests and blood tests, as well as completed questionnaires about their health, lifestyle and medical history over the course of the study.
In the blood samples, the scientists isolated the healthy fatty acids found in fish oils: docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA). This showed researchers how much fish each person ate.
Among the participants, those with higher levels of all three fatty acids in their blood had a 35 percent lower risk of dying of heart disease than those with lower levels. Each fatty acid also had specific associations. DHA was connected with a 40 percent lower risk of death from coronary heart disease (a condition in which the gradual buildup of plaque in heart-vessel walls results in heart failure), EPA was associated with a lower risk of heart attacks and high levels of DPA meant a participant was less likely to die of a stroke.
When scientists considered other causes of death as well, participants with the highest level of the three fatty acids were 27 percent less likely to die during the study period and lived on average two years longer than participants with the lowest levels.
According to the researchers, the results highlight how beneficial omega-3 fatty acids can be for longevity. If you don’t already eat fish, it isn’t too late to start. The greatest benefit from omega-3-fatty acid levels was seen among participants who shifted from a diet low in fish to taking about 400 mg of fish oil daily. This equals about two servings of fish per week as recommended in the Dietary Guidelines for Americans and the American Heart Association.
If you’d rather eat fish than take fish oil, you should shoot for two 3.5 ounces of cooked or a ¾ cup of flaked fish per week. Fish rich in omega-3 fatty acids include salmon, mackerel, herring, lake trout, sardines and albacore tuna.