Food and depression are related, according to a study from University College London, published in the British Journal of Psychiatry. This study showed that people who consume more processed food are prone to depression, while those who eat more fruits and vegetables are significantly less prone to depression.
Research on a sample of about 3,500 volunteers in England showed that those who consume the most milk and dairy products with high-fat, processed meats, refined grains, fried snacks and sweetened desserts in period of 5 years, were 58% more likely to suffer from depression than other group of volunteers, who consumed more fruits and vegetables, for the same period of 5 years. Results that followed were 26% less prone to suffer from depression.
Of course, we must be aware that this does not mean that a poor diet causes depression, but it is a reliable indicator that is associated with it.