Overview
- Researchers found that cutting dietary fat or reducing animal-based protein for four weeks was tied to a drop in a biomarker-based age score in people aged 65 to 75.
- The randomized study assigned 104 participants to four diets that held protein at 14 percent of energy and varied fat, carbohydrate, and plant versus animal protein sources.
- The omnivorous high-carbohydrate plan showed the strongest reduction in the biological age estimate, while the omnivorous high-fat plan showed no meaningful change.
- Scientists calculated biological age from 20 measures, including cholesterol, insulin, and C‑reactive protein, to reflect how the body is functioning rather than years lived.
- The authors emphasize that the effect is preliminary, limited by the short duration and narrow eligibility, and they call for larger and longer trials to test durability and disease risk.