Sydney Study Finds 4 Weeks of Diet Changes Lower Biological Age in 104 Older Australians
Updated
Updated · ScienceBlog.com · May 12
Sydney Study Finds 4 Weeks of Diet Changes Lower Biological Age in 104 Older Australians
9 articles · Updated · ScienceBlog.com · May 12
A 104-person University of Sydney feeding trial found that four weeks of diet changes shifted biomarker-based biological age lower in adults aged 65 to 75, with three of four diet groups improving.
The clearest result came from a high-carbohydrate omnivorous diet—53% of energy from mostly whole grains, legumes and vegetables—while the high-fat omnivorous diet closest to typical Australian eating showed no meaningful change.
Researchers held protein at 14% of energy and delivered all meals for a month, aiming to isolate the effects of fat-to-carbohydrate balance and plant-versus-animal protein on the Klemera-Doubal biological age score.
That score combines roughly 7 to 15 biomarkers, including C-reactive protein, insulin, cholesterol, blood pressure and waist circumference, suggesting the shift reflected a coordinated physiological response rather than one fast-moving lab value.
The authors called the findings a proof of concept, not evidence of longer life, and said larger, longer studies are needed to test whether the short-term biomarker gains reduce disease or mortality.
Scientists reversed biological age in just four weeks. What happens to the body in week five?
A high-carb diet reversed aging in a month. Is your popular low-carb diet secretly harming you?
Four-Week Dietary Interventions Significantly Reverse Biological Age in Adults 65–75
Overview
A recent study published in May 2026 shows that dietary changes can quickly reverse biological age, with measurable improvements seen in just four weeks among adults aged 65 to 75. This breakthrough suggests that it’s never too late to benefit from better nutrition, offering hope for healthier aging. However, researchers stress that these results are still early and it’s not yet clear if the changes last or build up over time. More research is needed to understand if these rapid improvements in biological age truly lead to better long-term health outcomes.