Individuals who ate a Mediterranean-style diet were 30 per cent less likely to suffer from depression, compared to those who had the lowest Mediterranean diet scores, according to a study with over 10,000 people published in the Archives of General Psychiatry.
“The results of our analysis suggest the possibility that the Mediterranean dietary pattern is protectively associated with depression,” wrote the researchers, led by Almudena Sanchez-Villegas from the University of Las Palmas de Gran Canaria and the University of Navarra, Pamplona.
“We acknowledge that our findings must be confirmed by additional prospective studies with better control of other potential confounders and also by trials with a more objective and rigorous assessment of the outcome,” they added.
The Med diet, rich in cereals, wine, fruits, nuts, legumes and whole grains, fish and olive oil, and low in dairy, meat, junk food and fat , has been linked to longer life, less heart disease, and protection against some cancers. The diet's main nutritional components include beta-carotene, vitamin C, tocopherols, polyphenols, and essential minerals.
The researchers analysed dietary information from 10,094 healthy Spanish participants and researchers calculated their adherence to the Mediterranean diet based on nine components, including the ratio of monounsaturated fatty acids to saturated fatty acids, moderate alcohol and dairy product intakes, low meat intake, and high intake of legumes, fruit, nuts, cereals, vegetables and fish.
After an average of 4.4 years of follow-up, depression had been documented in 156 men and 324 women. Closely adherence to the Mediterranean diet, indicated by higher Med diet scores, was associated with a 30 percent reduction in the risk of depression, compared to people with the lowest scores.
“The specific mechanisms by which a better adherence to the Mediterranean dietary pattern could help to prevent the occurrence of depression are not well known,” wrote the researchers.
Sanchez-Villegas and her co-workers indicate that the dietary components may decrease the chances of developing depression by improving blood vessel function, fighting inflammation, reducing the risk for heart disease, and repairing oxygen-related cell damage.
“However, the role of the overall dietary pattern may be more important than the effect of single components,” they wrote.
“It is plausible that the synergistic combination of a sufficient provision of omega-three 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.”
Source: Archives of General Psychiatry
Volume 66, Number 10, Pages 1090-1098
“Association of the Mediterranean Dietary Pattern With the Incidence of Depression: The Seguimiento Universidad de Navarra/University of Navarra Follow-up (SUN) Cohort”
Authors: A. Sanchez-Villegas, M. Delgado-Rodriguez, A. Alonso, J. Schlatter, F. Lahortiga, L.S. Majem, M.A. Martinez-Gonzalez