Valter Longo

Professor of Gerontology

USC Leonard Davis School

Valter D. Longo is an Italian-American biogerontologist and cell biologist known for his studies on the role of fasting and nutrient response genes on cellular protection aging and diseases and for proposing that longevity is regulated by similar genes and mechanisms in many eukaryotes. He is currently a professor at the USC Davis School of Gerontology with a joint appointment in the department of Biological Sciences as well as serving as the director of the USC Longevity Institute.

Valter Longo is a Professor of Gerontology at the USC Leonard Davis School of Gerontology who is internationally recognized for his research on caloric restriction, fasting, and cellular regeneration as mechanisms to slow aging and extend healthspan.

Mechanism of action

Longo's research focuses on how periods of reduced caloric intake and fasting activate cellular stress-response pathways, including autophagy (cellular self-cleaning) and metabolic switching, which are thought to promote cellular regeneration and extend lifespan in model organisms. His work has centered on understanding how these nutritional interventions modulate growth signaling pathways, particularly involving insulin-like growth factor 1 (IGF-1) and mTOR, which appear to influence aging rates and disease susceptibility. His laboratory has also investigated how fasting can trigger stem cell activation and immune system renewal, potentially reducing inflammation and improving resilience to age-related decline.

Evidence overview

Longo's research program has produced substantial evidence in model organisms (yeast, mice, and nematodes) demonstrating that caloric restriction and fasting protocols can extend lifespan and improve healthspan markers. His work has contributed to understanding the molecular mechanisms linking nutrient sensing to aging, particularly the role of mTOR and IGF-1 pathways. Clinical studies and observational data suggest that fasting-like dietary approaches (such as his proposed "Fasting Mimicking Diet") may improve metabolic health and reduce disease markers in humans; however, long-term randomized controlled trials confirming lifespan extension or major healthspan benefits in humans are limited. His high-impact publications have made him one of the most-cited researchers in the aging field, though some of his more ambitious claims regarding reversal of aging require further validation in human populations.