In a study of 106 healthy volunteers, researchers found that participants who had lower blood levels of omega-3 polyunsaturated fatty acids were more likely to report mild or moderate symptoms of depression, a more negative outlook and be more impulsive. Conversely, those with higher blood levels of omega-3s were found to be more agreeable.
"A number of previous studies have linked low levels of omega-3 to clinically significant conditions such as major depressive disorder, bipolar disorder, schizophrenia, substance abuse and attention deficit disorder," said Sarah Conklin, Ph.D., a postdoctoral scholar with the Cardiovascular Behavioral Medicine Program in the department of psychiatry at the University of Pittsburgh School of Medicine. "However, few studies have shown that these relationships also occur in healthy adults. This study opens the door for future research looking at what effect increasing omega-3 intake, whether by eating omega-3 rich foods like salmon, or taking fish-oil supplements, has on people's mood."
The American Heart Association recommends that all Americans consume fish, which is high in omega-3 fatty acids, twice per week. This recommendation is based upon evidence that a diet high in fish s associated with improved heart health and reduced risk for heart-related problems. While the cardiovascular benefit of increasing omega-3 intake is well recognized, relatively little is known of the potential mental health effects among the general public.
Comparisons were made by analyzing levels of omega-3 fatty acids in participants' blood and comparing that data to the participants' scores on three accepted tests for depression, impulsiveness and personality. The amount of omega-3 circulating in blood reflects dietary intake of the fatty acid. The study did not require participants to make changes in their normal diet habits.
In addition to Dr. Conklin, co-authors of the study, which was funded by the National Heart, Lung and Blood Institute of the National Institutes of Health (NIH), include: Jennifer I. Harris, M.D., psychiatry resident, department of psychiatry, Brown University; Stephen B. Manuck, Ph.D., University Professor of Health Psychology and Behavioral Medicine, department of psychology, University of Pittsburgh; Joseph R. Hibbeln, M.D., chief of outpatient clinic, Lab of Membrane Biophysics and Biochemistry, National Institute on Alcohol Abuse and Alcoholism, NIH; and Matthew F. Muldoon, M.D., associate professor, department of medicine, University of Pittsburgh School of Medicine.