People who eat a diet laden with processed and high-fat foods may put themselves at greater risk of depression, according to researchers at the University College London. In a study published in the British Journal of Psychiatry, the researchers also found that eating a whole food diet with plenty of fresh vegetables, fruit and fish could help prevent the onset of depressive symptoms in middle age.

 

Though previous studies have examined the effects of individual nutrients, the researchers say their study is the first to examine the association between overall diet and depression.  The researchers studied 3,486 people with an average age of 55 and who worked in civil service departments in London. Each participant completed a questionnaire about their eating habits, and a self-report assessment for depression.

 

The researchers found that people with the highest intake of whole food were less likely to report having symptoms of depression. In contrast, high consumption of processed food was associated with increased odds of depression. The associations between diet and onset of depressive symptoms remained after the researchers controlled for other indicators of a healthy lifestyle, such as not smoking, taking physical activity and a healthy body mass.

 

 “Our results suggest that consuming fruits, vegetables and fish may afford protection against the onset of depressive symptoms, whereas a diet rich in processed meat, chocolates, sweetened desserts, fried food, refined cereals and high-fat dairy products would increase people’s vulnerability,” the researchers say.

 

The researchers said that further research is needed to explain why eating processed food is associated with higher risk of depression, but they suggested it could be because a processed food diet is associated with a higher risk of coronary heart disease and inflammation, which are known to be involved in the development of depression. They also speculate that antioxidants, folate and certain types of fatty acids found in whole food diets could provide protective effects that lower the risk for depression.

 

 “The deleterious effect of a processed food diet on depression is a novel finding,” the authors of the study say. “Our research suggests that healthy eating policies will generate additional benefits to health and well-being, and that improving people’s diet should be considered as a potential target for preventing depressive disorders.”