The typical American diet currently contains 20 times more omega-6 than omega-3. This imbalance may put people at greater risk for both clinical depression and certain inflammatory diseases, according to researchers at Ohio State University (OSU), Columbus.
The study, conducted in OSU's Institute for Behavioral Medicine Research, included 43 middle-aged to elderly men and women, nearly half of whom were caregivers of spouses with Alzheimer's disease or other dementias. Researchers included caregivers, who typically report greater stress and more depression than those who are not caregivers, in order to study how depression and diet might interact to affect inflammation.
Blood samples were drawn from each person and tested. Participants also completed a questionnaire that gauged their level of depression.
The analysis showed that participants who had much more omega-6—compared to omega-3—fatty acids, and who also were reporting more symptoms of depression, had much higher levels of two cytokines which enhance inflammation.
“In this study, we're looking at the intersection of behavior, immune function and diet. In past experiments, we concentrated only on the first two,” explains Jan Kiecolt-Glaser, lead author and professor of psychiatry and psychology, OSU. “It now appears that diet is a very important variable in the equation as to how people respond to depression and stress.”
Researchers concluded that omega-3 intake only needed to be increased slightly to have impact. “This study has shown that even in people who did not take supplements, maybe just a little bit more omega-3 could help reduce their markers for both stress and depression,” Martha Belury, co-author of the study and associate professor of human nutrition, endocrinology, diabetes & metabolism, OSU. “The important message for consumers is that they don't have to take mega-doses of omega-3 to have some impact.”
