Brain Hormone FGF21 Orchestrates Body's Adaptive Response to Protein Restriction and Longevity

Researchers at LSU's Pennington Biomedical Research Center propose that the hormone FGF21 coordinates a body-wide response to low protein availability, linking nutrient sensing to metabolic changes and altered food preferences. Studies in fruit flies and mammals demonstrate that FGF21 signaling in the brain is essential for protein restriction to extend lifespan and modify how organisms use energy. This framework suggests the brain plays a central role in organizing adaptive responses to nutritional scarcity that may promote healthy aging.

Researchers at LSU's Pennington Biomedical Research Center have identified FGF21, a hormone that serves as a molecular messenger between nutrient availability and the brain's regulatory systems. When protein becomes scarce, this hormone appears to trigger coordinated changes across multiple bodily systems, including shifts in energy metabolism and food-seeking behavior. Studies in both fruit flies and mammals have shown that this hormone signaling is necessary for the lifespan-extending benefits of protein restriction to occur.

The research team proposes that observable markers—such as changes in how the body regulates blood sugar, adjusts energy use, or develops cravings for protein—could serve as measurable indicators of this adaptive response. These biomarkers might eventually help explain why individuals respond differently to dietary changes based on factors like age, sex, and genetic background.