The imbalance of fatty acids in the typical American diet could be associated with the sharp increase in heart disease and depression seen over the past century, a new study suggests. Specifically, the more omega 6 fatty acids people had in their blood compared with omega 3 fatty acid levels, the more likely they were to suffer from symptoms of depression and have higher blood levels of inflammation-promoting compounds, report Dr. Janice K. Kiecolt-Glaser and her colleagues from Ohio State University College of Medicine in Columbus. These compounds, which include tumor necrosis factor alpha and interleukin-6, are “all-purpose ‘nasties’ for aging,” and have been tied to heart disease, type 2 diabetes, arthritis and other ailments…The researchers investigated the relationship among fatty acid consumption, depression and inflammation in 43 older men and women. The 6 individuals diagnosed with major depression had nearly 18 times as much omega 6 as omega 3 in their blood, compared with about 13 times as much for subjects who didn’t meet the criteria for major depression. Depressed patients also had higher levels of tumor necrosis factor alpha, interleukin-6, and other inflammatory compounds. And as levels of depressive symptoms rose, so did the omega 6 and omega 3 ratio.

—Anne Harding, reuters.com, 4/17/07