Depression is an established risk factor for the development of coronary heart disease (CHD). Dietary factors resulting in lower levels of omega-3 fats not only increase CHD risk, but may also cause depression.
Investigators measured red blood cell levels of two omega-3 fats, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and assessed depressive symptoms in a cross-sectional study of nearly 1,000 adults with CHD.
As EPA and DHA levels rose, depressive symptoms dropped. The prevalence of depression ranged from 23 percent in participants with the lowest blood levels of omega-3 fats to 13 percent in participants with the highest omega-3 blood levels.