Key Takeaway
Ketogenic diet started in middle-aged mice significantly extended median lifespan and preserved memory, grip strength, and motor function — potentially through mTORC1 signaling and increased protein acetylation.
Summary
Published in Cell Metabolism, this landmark study assigned C57BL/6 mice to ketogenic, low-carb, or control diets starting at 12 months of age (roughly middle-aged). Mice either lived out their natural lifespan or underwent physiological testing after 1-14 months of intervention.
The ketogenic diet significantly increased median lifespan and survival compared to controls. Beyond just living longer, KD mice maintained healthspan — they preserved novel object recognition (memory), grip strength, and motor performance into old age while control mice declined.
At the molecular level, the ketogenic diet increased protein acetylation and regulated mTORC1 signaling in tissue-dependent patterns, suggesting mechanisms similar to calorie restriction's longevity benefits. This was one of two simultaneous Cell Metabolism papers (the other by Newman et al.) establishing that ketogenic diets can extend both lifespan and healthspan in mammals.
Methods
- C57BL/6 mice assigned to ketogenic, low-carb, or control diet at 12 months
- Longevity cohort: natural lifespan tracking
- Healthspan cohort: physiological testing at 1-14 months post-intervention
- Tests: novel object recognition, grip strength, rotarod (motor), body composition
- Molecular: protein acetylation, mTORC1 signaling pathway analysis
Key Results
- Significantly increased median lifespan on ketogenic diet
- Preserved memory (novel object recognition) in aged KD mice
- Maintained grip strength and motor performance
- Increased protein acetylation levels
- Tissue-dependent regulation of mTORC1 signaling
Figures
Figure 1
Figure 2
Figure 3
Limitations
- Mouse study — longevity results may not translate directly to humans
- Started at mouse middle age; unclear if earlier or later start would differ
- Specific mouse strain (C57BL/6) may not generalize to other strains
- Long-term ketogenic diets are difficult to maintain in humans