Large-scale study finds that the Mediterranean diet is best for your mental health

Admittedly, eating chocolate or ice cream to chase the blues away is so much more enjoyable than healthy alternatives. But a new study published in the journal Molecular Psychiatry says that a diet rich in fish, nuts and vegetables could help lower a person's risk of depression. Specifically, a plant-based diet of fruit, vegetables, grains, fish, nuts and olive oil – but little meat or dairy – appears to have benefits in terms of mood.

The paper uses some sobering statistics to stress the mood disorder's prevalence and socioeconomic impact. Depression affects more than 300 million people worldwide, equivalent to 7 percent of all women and 4 percent of men. The World Health Organization estimates that about USD 1 trillion is lost each year because of low productivity caused by depression and anxiety disorders.

Researchers from Spain, Britain and Australia analysed 41 studies published within the last 8 years on the links between diet and depression. They found a connection between people's diet and their chances of developing depression. People who followed a strict Mediterranean diet had a 33 percent lower risk of being diagnosed with depression compared to people who were least likely to follow these eating habits.

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"There is compelling evidence to show that there is a relationship between the quality of your diet and your mental health," study lead author and research associate at University College London's Research Department of Epidemiology & Public Health Dr. Camille Lassale told 'CNN'. "This relationship goes beyond the effect of diet on your body size or other aspects of health that can in turn affect your mood."

The research team found that people who ate foods containing a lot of fat, sugar and processed meats were more likely to suffer from depression. "A pro-inflammatory diet can induce systemic inflammation, and this can directly increase the risk for depression," she added.

Findings were based on 5 longitudinal studies of 32 908 adults from Spain, France, the United Kingdom, Australia and the United States. Quoted in the British newspaper 'The Guardian', Lassale said: "Poor diet may increase the risk of depression as these are results from longitudinal studies which excluded people with depression at the beginning of the study. Therefore the studies looked at how diet at baseline is related to new cases of depression."

Naveed Sattar, professor of metabolic medicine at the University of Glasgow, wants to see more data before claiming outright that such diets improve mental health. "The current evidence is not sufficient to prove plant-rich diets can prevent depression as most of the evidence so far simply shows that those with poorer mental health eat worse. Also the link to inflammation as a plausible mechanism to explain a link between diet and mind health is highly tenuous."

The day may not be that far off when medical health professionals find room for dietary counselling alongside established forms of treatment for patients who are at risk of depression.