Studies Show Strong Association Between Diet and Depression

Two new studies have found that certain types of eating habits may reduce the odds of feeling depressed.

Almudena Sanchez-Villegas, PhD, of the University of Las Palmas de Gran Canaria, Spain, and her colleagues studied the eating habits of 10,094 healthy Spanish men and women. All of the subjects were assessed and found to be not depressed when the study began. During an average follow up of 4.4 years, 480 of the subjects had been diagnosed as depressed.

Overall, people who followed a Mediterraneanstyle diet were the least likely to be depressed.

The researchers used three different statistical approaches to analyze the relationship between the subjects’ eating habits and risk of depression. Depending on the model, people who most closely followed a Mediterranean-style diet were 31 to 41 percent less likely to be depressed. Some specific foods, such as fruits, nuts, olive oil, and legumes were associated with a lower risk of depression.

"However, the role of the overall dietary pattern may be more important than the effect of single components," wrote Sanchez-Villegas and her colleagues. "It is plausible that the synergistic combination of a sufficient provision of omega-3 fatty acids together with other natural unsaturated fatty acids and antioxidants from olive oil and nuts, flavonoids and other phytochemicals from fruit and other plant foods, and large amounts of natural folates and other B vitamins in the overall Mediterranean dietary pattern may exert a fair degree of protection against depression."

In the second study, Jean Golding of the University of Bristol, United Kingdom, and her colleagues investigated the eating habits of 9,960 women during their 32nd week of pregnancy and their risk of feeling depressed.

Golding reported that women who ate the most fish -- three or more servings weekly, equivalent to 1.5 grams of omega-3 fats -- were the least likely to be depressed. Women who consumed little or no fish were about 50 percent more likely to be depressed.

"A committee of the American Psychiatric Association has recommended consuming two or more portions of fish per week to avoid depression among the non-pregnant adult population, with additional omega-3 supplementation in the presence of emotional disorders," noted Golding.

References: Sanchez-Villegas A, Delgado Rodriguez M, Alonso A, et al. Association of the Mediterranean dietary pattern with the incidence of depression. Archives of General Psychiatry, 2009;66:1090-1098. Golding J, Steer C, Emmett P, et al. High levels of depressive symptoms in pregnancy with low omega-3 fatty acid intake from fish. Epidemiology, 2009;20:598-603.