The socio-economic and cultural context strongly influences the tastes and food choices of individuals. Together with the emotional stress caused by the lack of time to make objective choices, it affects our decision-making behavior, from shopping to the table, to the point that social psychology today speaks of “food conformity”.
More and more scientific studies show that the composition of the diet can greatly affect our life by affecting not only our health or our physical appearance, but also our energy, our way of thinking and even our mood.
For years I have been studying the cellular and molecular mechanisms that regulate appetite and the effects of metabolic disorders (especially obesity and type 2 diabetes) on brain function. The recent discoveries of the laboratory of neurochemistry and synaptic plasticity of the CNR, which I manage, together with the studies of other European and US laboratories, show that overt obesity is not only at the basis of metabolic, cardiovascular, respiratory and joint diseases, but also of disorders of the nervous system, because it alters the structure and function of synapses.
Each of the one hundred billion neurons that make up the brain develops on average ten thousand synapses, that is, connections with neighboring cells, which regulate cognitive and emotional behavior.
Our research revealed that obesity induced by a diet high in saturated fat, refined sugars and low in fiber causes an alteration in the number and functioning of synapses in the brain circuits responsible for the normal execution of tasks based on episodic memory (that which, for example, reminds us after days where we have hidden an object).
Similarly, the brains of obese mice and type 2 diabetes suffer from alterations to the circuits responsible for the homeostatic regulation of appetite so that the increase in cortisol in the blood triggers a neurometabolic reaction that causes hyperphagia, obesity and diabetes. The study shows that the process of regulating energy homeostasis is out of control in the obese and this prevents proper communication between the brain and the endocrine system.
Another example was found in the nerve circuit that controls the release of dopamine, the neurotransmitter of feelings of gratification and motivation. In the brains of obese mice, dopamine levels are higher than normal, causing desensitization of the circuits that control appetite, with effects on hunger to the point of inducing real “food addiction” behaviors, especially the most palatable one.
Some dietary interventions have emerged as potential regulators of synapse functioning, especially the Mediterranean diet. Furthermore, since neuroactive molecules produced by the fermentation of food by the bacteria of the intestinal microbiota also reach the brain, it is possible to intervene effectively on the synapses also by regulating the composition of the microbiota.
In the era of food conformity the message of Hippocrates (430 BC) “let food be your medicine and medicine your food” is more relevant than ever.