Intermittent fasting has gained popularity worldwide for its potential health benefits—diabetes, obesity, certain neurovegetative diseases, epilepsy—but its effect on somatic stem cells and tissue biology remained unknown.
A crucial question, however, examined in a study in mice (1), which shows that commonly used intermittent fasting diets inhibit the regeneration of hair follicles, by selectively inducing apoptosis in the affected stem cells (HFSC). cells). This effect is independent of caloric reduction, alterations in circadian rhythm, or the cellular nutrient-sensing mechanism mTorc1. Instead, fasting activates a defect in the transmission or restitution of a signal between the adrenal glands and the dermal adipocytes of the skin, triggering the rapid release of free fatty acids, which in turn disrupts metabolism. normal hair follicles and elevates their levels of cellular reactive oxygen species, causing oxidative damage and apoptosis.
A randomized clinical trial (NCT05800730) indicates that intermittent fasting inhibits human hair growth.
Less tissue regeneration
This study reveals an inhibitory effect of intermittent fasting on tissue regeneration and identifies interorgan communication, which eliminates activated HFSCs and stops tissue regeneration during periods of unstable nutritional intake.
These findings illustrate the principles and mechanisms by which intermittent fasting profoundly influences somatic stem cell and tissue biology, and define a comprehensive strategy for studying these effects.
Given the widespread adoption of this diet globally, it will be important in the future to thoroughly evaluate the effects of various fasting regimens on different stem cell systems to optimize these effects in humans and seek ways to mitigate their undesirable consequences, while retaining their benefits.
Professor Emeritus, Grenoble-Alpes University
(1) Chen H et al. Intermittent fasting triggers interorgan communication to suppress hair follicle regeneration. Cell. 2024 Nov 26:S0092-8674(24)01311-4
