N-3 oils, the brain and depression
In 1998, scientists observed, upon examining a variety of people living in France, New Zealand, an Japan, that there was a strong correlation between the incidence of heart attacks and major depression. How these two seemingly unrelated conditions could be linked was not to be discovered until subsequent studies were done. These studies found that both conditions were significantly lower in populations eating fish as the main staple.
Despite Japan's problems with overcrowding and high stress levels, they still had the lowest level of major depression. A number of studies have confirmed this early finding. New studies have shown that consumption of diets high in N-6 fats increased rates of major depression, and diets high in N-3 oils lowered depression rates. Trans fats played a major role as well.
...A number of studies have been done using people with major depression or by looking at large populations to see if risks are decreased or increased with varying amounts of the oils in the diets. The majority of these studies, especially the better conducted ones, show a positive effect. That is, supplying N-3 oils, either by supplementation or by diet, reduces depression and reduces the risk of developing depression.
Health and Nutrition Secrets (that can save your life), Dr Russell L. Blaylock, MD