Eating a lot of processed food may increase a person's risk for depression, researchers in Britain found.

Tasnime N. Akbaraly, Eric J. Brunner, Jane E. Ferrie, Michael G. Marmot and Mika Kivimak of the University College London analyzed data from 3,486 participants -- 26.2 percent women, mean age 55.6 years -- from the Whitehall II prospective study. Two dietary patterns were identified in the study -- "whole food," heavily loaded by vegetables, fruits and fish and "processed food," heavily loaded by sweetened desserts, fried food, processed meat, refined grains and high-fat dairy products.

Self-reported depression was assessed five years later using the Center for Epidemiologic Studies -- Depression (CES–D) scale.

The study, published in The British Journal of Psychiatry, found after adjusting for potential confounders, participants who ate at the highest levels of whole foods had lower risk of depression than those who ate the lowest levels of whole foods.

In middle-aged participants, a processed food dietary pattern was a risk factor for depression five years later, but a whole food pattern was protective, the researchers concluded.