By the Harvard School of Public Health
According to a recent study by the Harvard School of Public Health (HSPH) and the University of Washington, older adults who have higher blood levels of omega-3 fatty acids – found almost exclusively in fatty fish and seafood – may be able to lower their overall mortality risk by as much as 27 percent and their mortality risk from heart disease by about 35 percent. Researchers found that older adults who had the highest blood levels of the fatty acid lived, on average, 2.2 years longer than those with lower levels.
“Although eating fish has long been considered part of a healthy diet, few studies have assessed blood omega-3 levels and total deaths in older adults,” said lead author Dariush Mozaffarian, associate professor in the Department of Epidemiology at HSPH. “Our findings support the importance of adequate blood omega-3 levels for cardiovascular health, and suggest that later in life these benefits could actually extend the years of remaining life.”
Previous studies have found that eating fish, which are rich in protein and heart-healthy fatty acids, reduces the risk of dying from heart disease. But the effect on other causes of death or on total mortality has been unclear. With this new study, the researchers examined biomarkers in the blood of adults not taking fish oil supplements in order to provide the best assessment of the potential effects of fish consumption on multiple causes of death.
The researchers examined 16 years of data from about 2,700 U.S. adults ages 65 or older who participated in the Cardiovascular Health Study (CHS), a long-term study supported by the National Heart, Lung, and Blood Institute.
After adjusting for demographic, cardiovascular, lifestyle and dietary factors, Mozaffarian and his team found that three fatty acids – both individually and combined – were associated with a significantly lower risk of mortality.
Docosahexaenoic acid, or DHA, was most strongly related to lower risk of coronary heart disease death, especially due to arrhythmias. Docosapentaenoic acid (DPA) was most strongly associated with lower risk of stroke death, and eicosapentaenoic acid (EPA) most strongly linked with lower risk of nonfatal heart attack. None of these fatty acids were strongly related to other, noncardiovascular causes of death.
Overall, study participants with the highest levels of all three types of fatty acids had a 27 percent lower risk of total mortality due to all causes. When the researchers looked at how dietary intake of omega-3 fatty acids related to blood levels, the steepest rise in blood levels occurred when going from very low intake to about 400 mg per day.
“The findings suggest that the biggest bang-for-your-buck is going from no intake to modest intake, or about two servings of fatty fish per week,” said Mozaffarian.
This post is also available in: Chinese