By David Liu, PHD

Monday April 2, 2012 (foodconsumer.org) -- Eating baked foods such as fairy cakes, croissants, and doughnuts and fast food such as hamburgers, hot dogs and pizza may increase risk of depression, according to a new study.

The study published in the Public Health Nutrition journal showed that food consumers who ate fast food were 51 percent more likely than those who did not eat  to suffer depression.

The association was even dose-responsive, that is, high intake of fast food was associated with greater risk for depression, said Almudena Sánchez-Villegas, lead author of the study.

The study was not a  trial and a causal relation has not been established between eating baked food and fast food, and risk of depression.  It has been known that people under emotional stress were more likely to see comfort by eating food.  So caution should be exercised when the findings were interpreted.  

The study participants who ate the most fast food and commercial baked goods were found more likely to be single, less physically active and have poor dietary habits. This group of participants were less likely to eat healthy foods like fruit/vegetables, nuts, fish and olive oil.  They tended to be more likely to smoke and work more than 45 hours per week.

The researchers from the Canary Islands reported that even eating small quantities of baked food and fast food was linked to a significantly higher chance of developing depression.

The study was based on data from 8964 men and women enrolled in the SUN Project, who had never been diagnosed with depression or taken antidepressants.  Participants were followed for an average of six months and 493 of them were diagnosed with depression or began to take anti-depressive medications.

The current findings were in agreement with what was found 2011 from the same SUN project, which was released early in the PLoS One journal. In the early study of 12,059, 647 cases of depression were identified and eating fast food was correlated with a 42% increased risk of depression.

Sánchez-Villegas and colleagues concluded  "although more studies are necessary, the intake of this type of food should be controlled because of its implications on both health (obesity, cardiovascular diseases) and mental well-being."

Depression affects 121 million people worldwide.  Low income is one of the major factors for this mental disorder.  It's well known that low-income people have more things to worry about.

However, a person's diet has been associated early with the risk of depression. Studies showed that B vitamins, omega-3 fatty acids and olive oil were linked to lower risk. Again, low income people may be less likely to afford to buy healthy foods.