Scientists Explore Whether Reduced Protein Intake Could Extend Lifespan

While proteins are often equated with healthy eating, a comprehensive review of over 350 studies published in Cell Press Blue indicates a more nuanced relationship between protein intake and longevity. The research suggests that a diet with a slightly lower protein content, particularly in animal studies, correlates with better blood sugar regulation, reduced body fat, lower inflammation, and extended lifespan.

“

The recommendations should be adapted to age, health status, and level of physical activity.

Interestingly, animals on lower-protein diets often consumed more calories but expended more energy, maintaining a healthier metabolic profile. This effect may be linked to the hormone fibroblast growth factor 21 (FGF21), which increases with reduced protein intake and is associated with higher energy expenditure and improved insulin sensitivity. While FGF21 increases in humans, most evidence for its longevity impact comes from animal experiments.

“

The "but" refers to the fact that the research was mostly conducted on animals.

The review also points to specific essential amino acids, methionine, isoleucine, and valine, as potentially crucial in aging. Limiting these particular amino acids may replicate some benefits of lower-protein diets in experimental settings, as they are thought to influence cell growth, metabolism, and inflammation pathways. The authors stress that these findings do not imply a universal need to reduce protein intake, but rather highlight the importance of tailoring dietary recommendations to individual factors like age, health, and physical activity levels, noting that the needs of athletes differ significantly from sedentary individuals.

“

When the body receives less protein, the level of that hormone increases, and it is associated with higher energy consumption, greater insulin sensitivity, and more favorable metabolic changes.