The scientific study published in the “Nature Communications” journal

The more I eat the less memory and learning skills I have. This is the scientific data that emerges from the research conducted by the group coordinated by Sabatino Maione, Full Professor of Pharmacology at the Department of Experimental Medicine, Section of Pharmacology of the University of Campania Luigi Vanvitelli, in collaboration with the research group of the National Research council – CNR of Pozzuoli coordinated by the Researchers Vincenzo Di Marzo and Luigia Cristino and with Telethon Institute of Genetics and Medicine - TIGEM who identified a correlation between obesity and memory and learning capacity. The research was published in the prestigious “Nature Communications” journal.

"The study - explains Maione - highlights how obesity can alter important brain circuits in areas of the brain that continue to generate neurons for the entire life of the individual, through a defined mechanism of neurogenesis, such as the dentate gyrus of the hippocampus”.

The study was conducted on mice on a high-fat diet. After 8 weeks, the mice reached a weight 40% higher than those with a "standard" diet. Obese mice, compared to those with normal weight, scored lower on memory tests. At microscopic level, neurons in the hippocampus of obese mice lose the ability to enhance the exchange of information with neurons in other areas when stimulated with high-frequency electrical impulses.

"This phenomenon - explains Serena Boccella, one of the main authors of the study - is called long-term plasticity and represents the physiological mechanism that controls the learning and consolidation of different types of memory in humans. The impact on memory is such that the obese subject begins not to memorize his own food intake correctly (episodic memory) ".

This partly explains why our brain adapts to different eating habits and why when we gain weight, we continue to eat more and more.

"While on the one hand we have this vicious circle that is established at the level of the circuits that regulate hunger and satiety, there is also a general impact of obesity on the ability of individuals to lead a normal life in which memory and concentration play a main part of daily life such as work - states Maione - In the study we also identified the endogenous molecules involved in these complex mechanisms that underlie these phenomena of altered neurogenesis ".

In particular, "two molecules were identified in this study, the neuropeptide orexin and the endocannabinoid 2-arachidonoylglycerol, as responsible for the alteration of neurogenesis and of the normal functioning of the circuit that regulates episodic memory" continues Serena Boccella.

The study, which is very complex from an experimental technical point of view, explains a very simple phenomenon, namely that being overweight hinders the memorization of the act of eating itself, blurring the mind on the amount of food ingested and probably also altering its perception.

Therefore, obesity has an important impact on learning and on the episodic memory, which is the basis of the memories of the events of our life. In fact, the identification of the mechanisms involved in this process could open new perspectives in better understanding other pathologies that have selective damage to the episodic memory system.