Food and Mood
As many know, there is a well-known and documented relationship between serotonin and food intake , as well as between diet and mood. Just think of the
What is Serotonin
Serotonin is a neurotransmitter that acts on different receptor subtypes, thus exhibiting a wide range of functions that influence an equally wide range of organic activities. Among all, serotonin is particularly known for the ability to promote good mood and tranquility, among other things by decreasing food intake. In reference to this last point, it is believed that serotonin:
- determine an early onset of the satiety signal
- reduce the palatability of food and the total amount of food ingested
- reduce carbohydrate intake and increase protein intake ;
- does not affect fat intake and meal frequency
Medicines
It is no coincidence that agonist drugs of the serotonergic system – such as fluoxetine ( prozac ) – induce an immediate and significant decrease in food intake. These drugs are used in the treatment of depression , as – by increasing the levels of serotonin at the level of the nerve synapses – they improve the individual’s mood. They are also indicated in the treatment of bulimia nervosa, an eating disorder characterized by frequent binge eating , often compensated by self-induced vomiting or laxative abuse .
An agonist of the serotonergic system, fenfluramine, has long been used in the treatment of obesity , given its well-documented role in increasing serotonergic transmission and inducing satiety, both in humans and animals. Unfortunately, the marketing authorization was withdrawn in 1997, prompted by increasing reports of cases of pulmonary hypertension and heart valve disease .
Conversely, serotonergic antagonists – with an opposite effect compared to the previous ones, and as such used in the treatment of migraine – cause an increase in appetite.
How it works
Serotonin suppresses food intake by interacting mainly with a particular type of post-synaptic receptors, concentrated in the lateral extreme of the ventro-medial hypothalamic nucleus. Its anorectic action may also be linked to the reduction of the synthesis and release of neuropeptide Y, which increases the search for food, especially carbohydrates .
For the same reason, the brain concentration of serotonin can be modified with the choice of food; for example, foods high in simple sugars and tryptophan, such as chocolate, increase serotonin levels. It is therefore completely physiological and natural to look for foods rich in sugars when the mood is low and one is looking for serenity and tranquillity. However, the protracted introduction of high glycemic index carbohydrates creates insulin resistance , a situation which predisposes to type II diabetes and more generally to a dysmetabolic picture indicated by the name of syndrome X or metabolic. Among the various consequences there is also an obsessive need to introduce sugars (carbohydrate craving), due to a transient increase in serotonin, determined precisely by insulin , which improves mood.
Increase it with Food
To increase serotonin levels with food, without running the risk of gaining weight, it is necessary to eat low-calorie foods, rich in tryptophan but low in other amino acids such as leucine and phenylalanine . Unfortunately, this characteristic is only partially satisfied by some fruits, such as papayas , bananas and dates .
Another way to increase serotonin levels is to practice physical activity, since the muscles mainly use branched-chain amino acids , saving more tryptophan (see the article: branched-chain amino acids and central fatigue ).
These strategies are contraindicated in the presence of migraine, since in such circumstances elevating serotonin levels would contribute to further aggravate the problem.
Supplements
In mild mood disorders it is also possible – subject to medical consent – to resort to the specific integration of tryptophan, or better still of its derivative 5-hydroxytryptophan , present in foods in negligible quantities. This amino acid derivative, capable of crossing the blood-brain barrier , is proposed as an antidepressant, a valid aid against insomnia ( serotonin can be converted into melatonin ) and anorectic ( appetite inhibitor , especially the excessive need for sweet foods) .
