Diet May Affect Rate of Depression

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People who follow the Mediterranean diet may be less depressed, new research suggests. This diet includes olive oil plus many fruits, vegetables and whole grains. Protein often comes from fish, nuts, beans and legumes. The study included 10,000 healthy Spaniards. They regularly filled out a list of questions about mood and diet. Researchers kept track of them for an average of 4.4 years. Those who followed the Mediterranean diet most closely had a 30% lower rate of depression. This means that 70 people were depressed for every 100 people who didn't follow the diet as well. The study appeared in the journal Archives of General Psychiatry on October 5.

What Is the Doctor's Reaction?

We know you can’t eat your way out of depression. But a new study suggests that the so-called "Mediterranean diet" might lower your risk for developing depression. The study appears in the journal Archives of General Psychiatry.

How convincing is the study? It is far from proving its theory. Still, it does give us a good entrance to consider the idea that nutrition can seriously influence the biology of the brain.

The Mediterranean diet can reduce the risk of heart disease. It is similar in some ways to the DASH diet (dietary approaches to stop hypertension). Doctors often recommend the DASH diet for people with high blood pressure or heart disease.

The Mediterranean diet includes many more fruits, vegetables and whole grains than the average American diet. It is low in salt, saturated fat and cholesterol. It includes monounsaturated oils such as olive oil. A portion of your daily protein often comes from beans, lentils or other legumes, nuts and dairy foods. Most people who follow this diet drink a modest amount of regular alcohol.

Researchers began their study because of an intriguing trend. Depression is less common in Mediterranean countries than it is in Northern European countries. These authors skip right past other explanations for this. For example, there's the soothing sunny climate in the Mediterranean. And people there also enjoy a slower pace of living. But the authors focus on differences in diet as a possible explanation.

To test the influence of diet, the researchers surveyed 10,000 healthy Spaniards. They gave their subjects scores based upon how closely their eating habits fit into the pattern of a Mediterranean diet. After four and a half years, about 5% of the people in the study had been diagnosed with depression. People who followed a near-pure Mediterranean diet seemed to have depression less often than average. Their risk was about 30% lower.

This was not a "randomized" study. If it had been, researchers would have randomly assigned people who were similar to follow different diets. Given the design of this study, we can't say that the diet was the reason people with high Mediterranean diet scores had less depression.

What Changes Can I Make Now?

I loved a Persian poem that was up on the wall of my home when I was a child.

If of thy mortal goods thou art bereft,
And from thy slender store two loaves alone to thee are left,
Sell one, and with the dole
Buy hyacinths to feed thy soul.

Is there truly a diet by which you should best "feed thy soul?"

So far, experts do not consider diet habits to be a proven risk (or preventive strategy) for depression. We do know that genes (family history) contribute to depression. It is also clear that social circumstances can make depression more likely. Examples include abuse or social isolation.

If you develop depression, attention to diet and exercise is a nice idea. However, diet change is not a treatment for depression. It should not be substituted for appropriate care. Depression interferes with your daily functioning and puts you at risk for suicide.

Treatment options for depression include psychotherapy and medicines. The most effective plan for treating depression would involve both of these treatments.

Two kinds of psychotherapy are useful. Interpersonal psychotherapy helps you to sort out which people in your life support you and which are unreliable for you. It can help you to resolve stressful disputes and learn to take care of your own needs. Cognitive behavioral therapy teaches you to think positively. You will learn how to solve problems and rediscover simple pleasures.

Antidepressants are used to help stabilize and treat depression. If prescribed, they are usually taken for at least six months.

What Can I Expect Looking to the Future?

Good nutrition is a good idea. But I doubt that even further study will show that diet choices have much influence on rates of depression.

If diet does correlate with depression, is your choice of what to eat a cause of your depression? Or is it a side story?

Consider the way American eating habits are driven by family habits. The American lifestyle has become more frantic and busy. We have drifted away from sit-down family meals. We eat more fast foods, processed foods, packaged foods and instant recipes. Depression is more common in some cultures. But social expectations and the pace of living may be better explanations for these differences than the foods that we eat.