(Health Secrets) Breakthrough research is showing that people who eat a Mediterranean style diet are up to 50 percent less likely to develop depression compared to those following a standard American diet. While the general physical health benefits of the Mediterranean diet are well understood, the recent study by the University of Navarra in Spain is the first to look at the diet’s effect on mental health.
What is the Mediterranean diet?
The Mediterranean diet is more of an eating pattern than a specific diet. This is because there are a large number of countries around the Mediterranean, each with a distinct culture and varied cuisine, so a single diet combining these would be impossible.
The main characteristics of what we call a Mediterranean diet are:
- Plenty of fruit, vegetables, potatoes, nuts, beans, seeds, and bread
- Very little red meat
- Moderate portions of fish and poultry
- Low to moderate amounts of dairy products and eggs
- A lot of unsaturated fats, particularly olive oil
- Low to moderate alcohol consumption, with red wine being the main alcoholic drink
Evidence that the Mediterranean diet can prevent depression
The Spanish study published the Archives of General Psychiatry, followed the progress of over 10,000 adults who were all free from depression when they began the study.
These subjects were followed for a period of four to six years, during which they completed questionnaires that measured how well they followed various aspects of the Mediterranean diet. The questionnaires measured their intake of meat and fish, alcohol, dairy products, fruit and vegetables, nuts, seeds and beans, and olive oil.
The results of the study showed that after approximately four and a half years the incidence of depression in the subjects who had strictly followed the Mediterranean diet was around 30 percent lower than in those who hadn’t adhered to the rules of the diet.
These results were even more significant, showing up to a 50 percent reduced risk, in subjects who had followed specific parts of the diet, namely consuming large amounts of fruits, vegetables and olive oil.
How does the Mediterranean diet prevent depression?
Dr. Miguel A. Martinez-Gonzalez, chair of preventive medicine at the University of Navarra and co-author of the study, has suggested three possible explanations for the impact of the Mediterranean diet on mental health.
*One of the main causes of depression is thought to be a lack of BDNF (brain derived neurotrophic factor), a molecule that stimulates growth and function of nerve cells. BDNF is produced by the inner lining of blood vessels known as the endothelium, and this in turn is protected by consuming various elements of the Mediterranean diet. If the endothelium is well protected, BDNF will be produced and the chances of becoming depressed are reduced.
*Serotonin is a monoamine neurotransmitter that helps to prevent depression by regulating mood. When people with depression are treated with Prozac, it works by making more serotonin available within the brain. Olive oil is known to improve the binding of serotonin to its receptors, making it more effective at regulating mood and preventing depression.
*The natural omega-3 fatty acids present in the fish that form part of the Mediterranean diet are known to stimulate the central nervous system and to make it work more effectively. This in turn leads to increased brain function, allowing more effective regulation of mood and control of stress.
Should the Mediterranean diet be used to treat depression?
While the Mediterranean diet may well reduce the risk of developing depression, there is as yet no documentation to show that it is effective at treating a patient who is diagnosed as depressed. Counseling and drug treatment continues to be the standard of care after diagnosis. But the Mediterranean diet is food, not medicine, so there is nothing to lose by giving it a try.
The Mediterranean diet is recommended for a variety of other physical health reasons, mainly because people who follow the diet tend to have a reduced risk of heart disease, and lower cholesterol levels.
As it now seems that the Mediterranean diet also has benefits for mental health, it may well be recommended for people with a family history of depression, who are seen as being at high risk of developing depression themselves.