Franco Berrino: «The diet to fight depression»

The depression it is one of the leading causes of disability and suffering in the world. We all occasionally have moments of depressionbut the so-called major depression, of which two forms are distinguished, unipolar or bipolar, depending on the presence or absence of an alternation of depressive and manic phases, is a serious disease that affects more than 5 percent of the population. IS more frequent in women than in men (it is not known why) and it has an important genetic component, as demonstrated by studies on identical twins: if one falls ill with depression, it is probable that the other will also fall ill. But there are also environmental causes which, especially if we have cases of major depression in the family, it is good to know and avoid.

Berrino: «Why follow the Mediterranean diet»

Multiple studies, that is, have found that living in natural environments or in cities with lots of greenery reduces the risk of depression. For this reason, La Grande Via organizes “forest baths”, even sleeping in the forest for one or two nights, in which we actually see a strong reduction in anxiety and depression scores, as well as a significant reduction in cortisol. Also the food we eat is important. Prospective epidemiological studies show that the Mediterranean diet (whole grains, legumes, vegetables, fruit, extra virgin olive oil, nuts, fish in seaside places, a little wine and only occasionally meat and cheese) is protectivewhile diets that cause inflammation (rich in cured meats, red meats and sweets) and ultra-processed industrial foods (ready meals, fast food, sugary drinks) increase the risk of depression.

Nuts, soy and greens

These studies are sometimes difficult to interpret because people who tend to be depressed do not want to commit to cooking and eating healthy foods and prefer to resort to convenience foods, so it is difficult to establish whether it is bad food that causes depression or whether it is rather the early symptoms of depression that induce an inflammatory diet. There are, however, controlled clinical trials that demonstrate that the Mediterranean diet is really effective in reducing depressive symptoms. The mechanisms by which the Mediterranean diet protects they are multiple. Inflammation is an important cause of depression and the Mediterranean diet is rich in anti-inflammatory substances, such as omega-3 fatty acids (fats from fish, seaweed, also present in nuts, soybeans and some vegetables) and many polyphenols. Today the causes of inflammation are different, especially chronic stress and a Western diet, but the fact remains that those with high blood levels of inflammatory markers (especially C-reactive protein) are more likely to suffer from depression.

The antioxidants

Another mechanism is the richness of antioxidant substances in the Mediterranean dietIn fact, multiple studies have found greater oxidative stress in depressed people than in healthy people. Depression is associated with high blood levels of cortisol and low levels of BDNF (a factor that stimulates the proliferation of nerve cells, which is reduced in depressed people). And the Mediterranean diet contains numerous foods that inhibit cortisol and activate BDNF (omega-3, pomegranate, grape resveratrol). Diet has a strong impact on the composition of the intestinal microbiota. In laboratory animal studies it was found that the administration of probiotics containing bifidobacteria and lactobacilli reduces depressive symptoms. Interestingly, the substances used by neurons to transmit nerve impulses at synapses are largely produced in the intestine, many by intestinal bacteria. For example, 90 percent of the serotoninthe transmitter that depressed people lack, is produced in the intestines. Several vegetables (pineapples, bananas, kiwis, plums and tomatoes) contain serotonin, which, however, can hardly pass from the blood to the brain. Serotonin is synthesized from an amino acid, the tryptophan, which we take with the diet, therefore, to obtain an increase in cerebral serotonin, it is useful to consume foods rich in tryptophan, which passes the blood-brain barrier more easily. Multiple clinical studies have shown that small doses of tryptophan (1-3 grams per day) improve mood, increase expressions of joy, and reduce negative emotions (fear, sadness, disgust) in healthy people. Diets deficient in tryptophan, on the other hand, worsen mood and cause irritation and depression. Among the foods richest in tryptophan are: tofu, dates, nuts, peanuts, sesame seeds, eggs, turkey, cheese. However, since the other amino acids contained in proteins compete with tryptophan to cross the blood-brain barrier, one trick to allow it to reach the brain is to favor foods high in tryptophan from plants, or in any case associate them with foods rich in of carbohydrates (but not sugar).

tryptophan and serotonin

Carbohydrates stimulate insulin which promotes the entry of amino acids into muscle cells, with the exception of tryptophan, which will then be in the forefront of accessing the brain. Furthermore, to transform tryptophan into serotonin, the vitamin B6, of which oilseeds are very rich, especially walnuts.