A new study reveals that reducing fat intake and adopting a primarily vegetarian diet can reverse biological aging by approximately four years, with noticeable effects within just one month. Researchers in Australia tracked over 100 adults aged 65 to 75 for four weeks, monitoring 20 different biomarkers including cholesterol, insulin, and blood pressure to measure biological age—the age of the body's cells, which can differ from chronological age.
Study Design and Findings
Participants were randomly assigned to either an omnivorous diet, where half of their food came from animal sources and half from plants, or a semi-vegetarian diet, where most food sources were plant-based. They were further divided into subgroups based on higher fat or higher carbohydrate intake. The results showed that those on an omnivorous, high-carbohydrate diet were biologically about four years younger than those on a high-fat omnivorous diet. Similarly, participants on a vegetarian diet were biologically about three years younger than high-fat omnivores.
Mechanisms Behind the Results
The researchers believe that higher-carbohydrate diets, emphasizing whole grains, vegetables, and fiber, may reduce inflammation and improve cholesterol levels, thereby lowering the risk of chronic conditions like heart disease. Dr. Caitlin Andrews, lead author from the University of Sydney's School of Life and Environmental Sciences, noted, 'It’s too soon to say definitively that specific changes to diet will extend your life. But this research offers an early indication of the potential benefits of dietary changes later in life.'
Detailed Methodology
The study, published in the journal Aging Cell, evaluated 104 adults aged 65 to 75 with BMIs ranging from 20 to 35. Participants had no serious health conditions such as diabetes, cancer, or liver disease, and were non-smokers and non-vegetarians at baseline. They were divided into four diet groups: omnivorous high-fat (OHF), omnivorous high-carbohydrate (OHC), semi-vegetarian high-fat (VHF), and semi-vegetarian high-carbohydrate (VHC). The OHF diet was most similar to their baseline eating habits.
Results After Four Weeks
After four weeks, the OHC group—which consumed 14% protein, 28–29% fat, and 53% complex carbohydrates—showed a biological age reduction of 4.1 years. The VHF group saw a reduction of 3.2 years, and the VHC group 2.9 years. The OHF group showed no significant change. The experts caution that while these findings are promising, more research is needed on long-term effects. Dr. Alistair Senior, co-author, stated, 'Longer term dietary changes are needed to assess whether dietary changes alter the risk of age-related diseases.'
