WEDNESDAY MARCH 19, 2008 (foodconsumer.org) -- It's known that American diet contains too much of omega 6 fatty acids.   A new study now found that higher ratio of omega-6 to omega-3 fatty acid may have something to do with depression, or even other inflammatory diseases.

The study published in the journal Psychosomatic Medicine showed those who suffered major depression had a ratio of omega 6 to omega 3 fatty acids at 18:1 compared to 13:1 in those who were not depressed.

In the study, researchers from Ohio State University College of Medicine in Columbus examined fatty acid intake, inflammation and depression in 43 elderly people.   Six of the participants suffered major depression.

The researchers found higher ratios of omega-6 fatty acids to omega 3 fatty acids were associated with higher levels of depression.

The average hunter-gatherer diet containing high nuts and fish provides a ratio of two or three to one, which is believed to be the ideal ratio. In comparison, the ratio in the modern Western diet is about 15 to 17:1.

The researchers also found participants who were depressed had higher serum levels of tumor necrosis factor alpha, interleukin-6 and other compounds responsible for inflammation, meaning that high omega 6 fatty acids may be not good for inflammatory diseases.

The study results did not reveal a cause-and-effect relationship between the ratio of omega-6 to omega 3 fatty acids and depression, meaning a high ratio may not necessarily lead to depression.

Omega 3 fatty acids are found high in oily fish and nuts while omega 6 fatty acids are present in vegetable oils abundantly.