The direct relationship between the digestive system and the brain is proven, but researcher Almudena Sánchez wanted to go further. After working with over 20,000 people for 20 years, she has reached conclusions that may seem surprising, such as the Mediterranean diet being a way to prevent depression or improve its treatment. «The beneficial effects of heart-healthy diets decrease the risk of developing depression, and the Mediterranean diet is proving to be one of the best for this, especially when accompanied by the Mediterranean lifestyle.» She explained this in the Coffee with the Expert, a training space implemented by the Official College of Pharmacists of Las Palmas to establish more direct contact between trainers and registered members. On this occasion, the proposal was jointly presented by the departments of Teaching and Research, Clinical Analysis, and Public Health, whose heads are Jesús Pérez, Manuel Oliver, and Manuel Herrera, respectively.
According to the latest WHO estimates, 280 million people live with depression. The annual prevalence in Spain is around 5-6 %. Furthermore, it is one of the leading causes of disability.
«Unipolar depression can be considered,» explained Sánchez, «as a multifactorial illness where biological, psychological, and environmental factors appear to play a role. A significant number of studies suggest that depression shares pathophysiological mechanisms with metabolic syndrome, type 2 diabetes mellitus, obesity, and cardiovascular disease.».
In this regard, he pointed out that «the depressive process presents, among other characteristics, an increase in pro-inflammatory cytokine levels, endothelial dysfunction, oxidative stress, and metabolic alterations,» and added that «in recent years, the study of the preventive action of dietary patterns considered cardiovascularly healthy, including the Mediterranean diet, has gained great importance.».
The reasons seem clear with the studies conducted. «Between 30 and 40 % of people who develop depression present with low-grade systemic inflammation. The Mediterranean diet is anti-inflammatory, and this inflammation has a lot to do with neurotransmission,» he asserted.
Some observational design studies have found that following the Mediterranean diet is associated with a reduction in depression risk of around 30%%. Furthermore, various small sample size clinical trials have found that intervention with the Mediterranean diet can decrease depressive symptomatology in patients with the condition. Additionally, the recent PREDIDEP trial found that following a Mediterranean diet supplemented with extra virgin olive oil was associated with a decrease in residual symptoms and an improvement in the quality of life of patients in remission from a depressive episode.
If a patient is undergoing treatment, «the diet does not substitute or remove the treatment; it is only an adjunct, and it serves as both treatment and prevention. This is something that has been observed in trials,» the scientist noted.
In addition to the Mediterranean diet – based on the consumption of virgin olive oil for raw food or cooking, vegetables, fruits, seasonal and minimally processed foods, whole grains, fish, and low intake of red meats – it's also important to consider the Mediterranean lifestyle, which includes physical activity, meals with friends and family, seasonal products, and so on.
Further intervention studies with adequate sample size and long-term follow-up are needed to confirm these findings.
