Specific Diets Associated with Lower Biological Age in New Research Findings - Video

A few simple changes on the dinner plate may be able to make the body biologically younger-and the effects could appear in just a month.

Researchers from the University of Sydney have found that older adults who reduced either dietary fat or animal-based protein showed measurable improvements in biological aging markers after only four weeks. The study, published in Aging Cell, suggests that targeted dietary changes later in life may rapidly influence health and aging processes.

Unlike chronological age, which increases year by year, biological age reflects how well the body is actually functioning. Scientists estimate biological age using biomarkers linked to inflammation, metabolism, and overall physiological health.

In this study, researchers analyzed 20 biomarkers, including cholesterol, insulin, and C-reactive protein levels, to calculate participants’ biological age profiles. The trial involved 104 adults aged 65 to 75 who followed one of four carefully designed diets. Two diets were omnivorous, while the other two were semi-vegetarian with most protein coming from plant sources. Participants were also assigned either high-fat, low-carbohydrate diets or lower-fat, higher-carbohydrate diets.

Researchers found that the group eating an omnivorous high-fat diet — which most closely matched participants’ usual eating habits — showed virtually no change in biological age. In contrast, the other three dietary groups experienced reductions in biological age markers. The strongest improvements were seen in participants who consumed a lower-fat, higher-carbohydrate omnivorous diet.

However, scientists caution that the results are preliminary. The study lasted only four weeks, making it unclear whether these biological changes are long-lasting or whether they ultimately reduce the risk of diseases linked to aging.

The findings add to growing evidence that what people eat may influence not only weight and heart health, but also how quickly the body ages at a biological level.

REFERENCE: Andrews, C. J., et al. (2026). Short‐Term Dietary Intervention Alters Physiological Profiles Relevant to Ageing. Aging Cell. DOI: 10.1111/acel.70507. https://onlinelibrary.wiley.com/doi/10.1111/acel.70507