Highlights
- A large cohort of mice was put on calorie restricted diet to study why calorie restriction improves longevity
- Weight loss and metabolic improvements did not explain the longevity benefits of severe dietary restrictions
- The study indicated that improved immune health is the likely cause of longer life in these mice
Calorie restriction (CR) leads to longevity but alternatives are needed
Sticking with a CR lifestyle is hard to do, hunger low energy, muscle loss and many other side effects are well known. so the study authors sought to try to find some alternative regimens. Does intermittent fasting work? How does it compare against a full CR diet? The answers can provide us with clues as to whether we can potentially do less rigorous CR or fast intermittently and still get mosts the benefits of CR.
Better immune health may be the secret to longer life in mice
Weight loss and metabolic changes might not be what lead to a longer life on a low-calorie diet. Researchers fed 960 mice low-calorie diets or subjected them to regular bouts of fasting. While the diet regimens did cause weight loss, factors such as immune health seemed to better explain the link with increased lifespan. Also key was overall resilience, presumably encoded in the animals’ genes, to the stress of reduced food intake. The most-resilient animals lost the least weight, maintained immune function and lived longer.
Health improvement and life extension are not the same
This study raises important questions about which outcomes measures are the most important in deciding whether an anti-aging intervention is effective. Perhaps improvements in immune health is the better measure in deciding whether such an intervention is effective.
Dolgin, E. Eating less can lead to a longer life: massive study in mice shows why https://doi.org/10.1038/d41586-024-03277-6
Di Francesco, A., Deighan, A.G., Litichevskiy, L. et al. Dietary restriction impacts health and lifespan of genetically diverse mice. Nature 634, 684–692 (2024). https://doi.org/10.1038/s41586-024-08026-3