In the last period, talking about fasting is something that in a certain sense is very fashionable. Diets that exploit the absence of food for hours are multiplying, such as that of intermittent fastingas a way to lose weight quickly. Assuming that every type of diet must be followed under strict medical supervision, there is a study coordinated by Paola Tognini, a researcher in the Translational Research department of the‘University of Pisa (Physiology Unit) and published in the journal of the Springer-Nature group Cellular and Molecular Life Scienceswhich demonstrated how the absence of food causes alterations in the gene expression of the cerebral cortex in our body, affecting in particular the biological clock.
Researchers have demonstrated that beta-hydroxybutyrate, a ketone body produced by our body during fasting conditions, has the ability to alter both chromatin (a mass of genetic tissue composed of DNA and proteins that condenses to give shape to chromosomes throughout the eukaryotic cellular department, which is found within of the nucleus of our cells, ndr) that gene expression in the cerebral cortex. “The absence of food represents a stressful stimulus for our body, which has to respond to the energy demands of a large number of tissues” explains Dr. Tognini.
“Glucose is no longer sufficient, and our body begins to produce ketone bodies as an alternative energy source. Beta-hydroxybutyrate is the major ketone body that reaches the brain during periods of fasting. In the past it was thought that the brain used beta-hydroxybutyrate only as a substrate to produce energy, but this is not the case. In collaboration with the metabolomics laboratories of Dr. Amalia Gastaldelli and the proteomics laboratories of Dr. Silvia Rocchiccioli of Cnr-Ifc, we used high-resolution mass spectrometry techniques to measure the concentrations of beta-hydroxybutyrate in the liver (where it is mainly produced), in the plasma (where it is released) and in the brain by discovering that brain cells also exploit beta-hydroxybutyrate as a chemical donor, causing alterations in the structure of proteins, in particular proteins found in the cell nucleus and which are contact with DNA (the so-called chromatin). As a result, we discovered dramatic changes in gene expression brain”, explains the doctor.
The major changes occur with regard to thecircadian clock, which represents a system for regulating biological processes in synchrony with the alternation of day and night throughout the 24 hours. “Our experiments showed that not only the levels of clock genes were altered but also the locomotor activity undergoes changes. It has also been verified that these circadian rhythm variations are maintained even after the reintroduction of food, suggesting the existence of a memory trace in the circuits involved in the control of these rhythms”, he adds Sara Cornutidoctoral student of the Higher Normal School and first author of the article.
Therefore, this new research, demonstrating how fasting is a powerful regulator of gene expression levels in the central nervous system, opens new frontiers for the use of nutrition as alternative strategies or adjuvants for the treatment of neurodevelopmental or neuropsychiatric disorders.