New Study Reveals Four-Week Approach Linked to Reversed Biological Aging - Video

Diet may influence biological ageing markers in older adults within just four weeks, according to new research from the University of Sydney.

Published in Aging Cell, the study included 104 Australians aged 65 to 75 who were randomly assigned to one of four diets. Researchers examined whether changing fat, protein and carbohydrates affected biological age.

Biological age differs from chronological age. It estimates how old the body appears based on markers. Researchers calculated biological age using 20 biomarkers, including cholesterol, insulin and C-reactive protein.

All four diets provided 14% of energy from protein. Two were omnivorous, with half of protein from animal foods, while two were semi-vegetarian, with 70% from plants. Each dietary pattern was either higher in fat and lower in carbohydrates or lower in fat and higher in carbohydrates.

Participants following the omnivorous high-fat diet showed no meaningful change in estimated biological age. However, the other three groups showed reductions in the biological age calculated from their biomarker profiles.

The strongest evidence was seen in the omnivorous high-carbohydrate group, providing about 28-29% of energy from fat and 53% from carbohydrates.

Overall, these new findings suggest that reducing dietary fat, animal-based protein, or both may influence ageing-related biomarkers in older adults over a short period.

However, a lower biological age score does not mean ageing has been permanently reversed. The study also cannot show whether these changes will last or reduce age-related diseases or extend lifespan.

The researchers stressed that longer studies are needed to determine whether the biomarker changes persist and whether similar effects occur in younger or different populations.

REFERENCE: Caitlin J. Andrews, Rosilene V. Ribeiro, Alison Gosby, David G. Le Couteur, David Raubenheimer, Jian Tan, Stephen J. Simpson, Alistair M. Senior. Short‐Term Dietary Intervention Alters Physiological Profiles Relevant to Ageing. Aging Cell, 2026; 25 (5) DOI: 10.1111/acel.70507