Diet Change May Slow Biological Aging in Older Adults

Introduction

Aging is influenced by diet, which may speed up or slow down the body's decline. This study tested whether changing protein source and carbohydrates could affect biological age—a measure of how well the body functions—in older adults.

What the study did

Researchers analyzed data from 104 adults aged 65-75. Participants were randomly assigned to one of four diets for 4 weeks: omnivorous (meat-eating) with high fat, omnivorous with high carbs, semi-vegetarian with high fat, or semi-vegetarian with high carbs. They measured biological age using a method called the Klemera-Doubal Method, which uses blood markers to estimate how old the body seems.

What it found

• People on the omnivorous high-fat diet, which was similar to their usual eating, showed no change in biological age.
• Compared to that group, those on the omnivorous high-carb diet had a significant reduction in biological age.
• The semi-vegetarian groups (both high-fat and high-carb) also showed reductions in biological age, though not all were statistically significant.
• These changes appeared within just 4 weeks, suggesting diet can quickly affect biological age markers.

How much to trust it

This is a randomized controlled trial, a strong design for a single human study, earning a 'Good' trust tier. However, the study lasted only 4 weeks, so we don't know if these changes last or reduce disease risk. Also, the changes might reflect short-term responses to diet, not true aging reversal.

Your action plan

• Consider increasing carbohydrates in your diet, as the study found this was linked to lower biological age.
• Try incorporating more plant-based meals, as semi-vegetarian diets showed similar benefits.
• If you're over 65, talk to a professional about how diet changes might affect your health.
• Remember, this is a short-term study; long-term effects are unknown.

This summary is for general information only and is not medical advice. Talk to a qualified professional before changing anything about your health.

Source

Short-Term Dietary Intervention Alters Physiological Profiles Relevant to Ageing.. Aging cell. 2026 PubMed