Mediterranean Diet and Mental Health

Mental health disorders, primarily depression, are among the leading causes of the global health burden of disease (1). Depression is characterized as a condition where a person feels discouraged, sad, unmotivated, or hopeless for over two weeks and this interferes with their daily activities, behavior, functions, and thoughts. In recent events, the emergence of the coronavirus disease (COVID-19) pandemic triggered an alarming increase of 25% in the global prevalence of depression (2). Today, depression is ranked among the 25 leading causes of burden globally, with no reduction in global prevalence despite compelling evidence of its impact. This is specifically true in low-middle income countries (LMIC) in the Eastern Mediterranean Region (EMR), with prevalence soaring up to 63%, owing to prolonged conflict, political instability, and economic collapse (3, 4).

Prevention, diagnosis, and treatment of depression are crucial, as they are associated with a significant decrease in a patient’s well-being, disability, and social functioning. Additionally, depression may cause considerable pain and suffering to the individual, and their surroundings (5). Despite the evident drawbacks, misunderstanding and social stigma remain fundamental barriers to seeking treatment (6). This results in a lack of engagement, adherence, and utilization of mental health services and treatments (7). In the EMR, public stigma has been identified as a key barrier to seeking and engaging in mental health treatment (8). Alternative methods have successfully shown a reduction or treatment of depressive symptoms including food and optimal dietary habits.

Whilst several studies have focused on the effect of specific nutrients or foods on mental health, there is a growing interest in the impact of the overall diet. This stems from the understanding that people do not consume single nutrients; rather, they consume foods which contain different combinations of nutrients that interact synergistically and in a complex manner (9). Therefore, dietary patterns may be more representative of real-life eating patterns as they consider the combined effect of foods and nutrients. The Mediterranean diet is one of the most commonly examined dietary patterns in the field of mental health and its positive impact on depression has been well-established (10).

The Mediterranean diet refers to the dietary habits of people living in countries near the Mediterranean Sea, such as Greece, Italy, Spain, and Lebanon, and is based on the traditional cuisine of these countries. It is regarded as one of the healthiest diets and its health benefits have been widely discussed in the literature. It traditionally emphasizes the consumption of plant-based foods including fruits and vegetables, whole grains, legumes, nuts and seeds, herbs and spices, olive oil, in addition to fish and red wine, while it limits the intake of dairy products, red meat, and sweets. The Mediterranean diet pattern has been shown to exert its positive effects mainly through its anti-inflammatory and antioxidant properties. For instance, this diet is rich in polyphenols, vitamins C and E, selenium, and carotenoids, all of which are rich sources of antioxidants (15). In addition, this dietary pattern has previously shown to have a protective effect on psychological disorders due its richness in fibers, omega-3 fatty acids, vitamins B and E, and magnesium (16). All of these components interact together in a synergistic manner to reduce cytokines and inflammatory markers and improve the levels of the brain-derived neurotrophic factor, thus improving cognitive function (17).

Nonetheless, the regional disparities between the Mediterranean countries may incur variations within the same dietary pattern, and this is mainly due to the economic, religious, and socio-cultural factors that may differ between one country and the other (11). Regardless of these disparities, recent research has indicated that there is indeed a direct relationship between a Mediterranean diet and mental health. The PREDIMED trial is a multicenter, randomized, primary prevention study that aimed to compare the effect of a Mediterranean diet on the risk of depression following a 3-year dietary intervention  (13). Results obtained at follow-up showed that in comparison to a low-fat diet, adherence to a Mediterranean diet can exert a beneficial effect on depression by reducing its risk by 40%. Another prominent interventional study that evaluated the effectiveness of dietary interventions on the treatment of depression was the SMILES trial; a 12-week, parallel-group, randomized controlled trial  (14). Reportedly, there was a significant improvement in the symptoms of depression among participants who were assigned to the Mediterranean diet. Hence, the SMILES trial highlighted the possibility of addressing mood disorders through a diet that is feasible and accessible to the general population.

It is therefore crucial to highlight the positive impact of dietary pattern, specifically the Mediterranean diet, on mental health and well-being of individuals. Indeed, this must be emphasized in regions, where seeking treatment when needed is marred by public stigma and negative connotation.

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