A new study from the University of Sydney shows changing your diet late in life can slow biological aging in as little as a month.
Researchers assigned 104 participants aged 65 to 75 to one of four diets. Two were omnivorous, two were semi-vegetarian. Each derived 14% of energy from protein.
Biological age is based on biomarkers - not just years alive. Scientists measured cholesterol, insulin levels, and 18 other biomarkers.
After four weeks, participants in three of the four diet groups showed reduced biological age. Only those on the high-fat omnivorous diet saw no change.
Most improvement came from diets rich in complex carbohydrates and plant-based components.
Lead researcher Caitlin Andrews cautioned the results are preliminary. "It's too soon to say definitively that specific changes to diet will extend your life," she said. "But this research offers an early indication of the potential benefits of dietary changes later in life."