Short-term dietary shifts may lower biological age in seniors, study finds
A University of Sydney study of Australians aged 65 to 75 found that reducing dietary fat or animal-based protein for four weeks was linked to lower biological age markers. The most pronounced effect occurred in participants following an omnivorous, lower-fat, higher-carbohydrate diet. Researchers caution that the results are preliminary and require longer-term studies to confirm lasting benefits and broader applicability.
The trial enrolled 104 non-smoking adults aged 65 to 75 with BMIs between 20 and 35, excluding anyone with diabetes, cancer, or food sensitivities. Each of the four assigned diets supplied 14 percent of energy from protein, with the semi-vegetarian versions drawing 70 percent of that protein from plant sources. Researchers calculated biological age from 20 biomarkers, including cholesterol, insulin, and C-reactive protein, a common inflammation indicator.
Only the omnivorous high-fat group showed no meaningful shift in biological age. The other three groups—including both semi-vegetarian variants and the omnivorous lower-fat, higher-carbohydrate plan—displayed younger biomarker profiles after four weeks. The strongest effect emerged in the omnivorous lower-fat group, though investigators emphasize these results are preliminary and require longer-term confirmation.
If validated by longer studies, these findings could reshape how older adults approach nutrition, potentially offering a low-cost, accessible strategy for supporting healthy aging. Seniors, caregivers, and healthcare providers may look to short-term dietary adjustments as a practical complement to medical care. However, the four-week window and limited sample size mean broader populations—including younger adults and those with existing conditions—may not experience similar effects, so cautious interpretation remains warranted.