Turning back the body’s clock may not require miracle drugs or extreme fasting regimens. New research from the University of Sydney suggests that adults aged 65 to 75 can shift key markers of aging in just four weeks – simply by changing the balance of fat, carbohydrates, and animal protein on their plates.
The study followed 104 participants in the Nutrition for Healthy Living trial at the university’s Charles Perkins Centre. Each was randomly assigned to one of four diets, all providing 14 percent of daily energy from protein. Two of the diets were omnivorous, with half the protein from animal sources, while the other two were semi-vegetarian, with 70 percent of protein coming from plants. Within each pair, one version was higher in fat and lower in carbohydrates, and the other the reverse.
Biological age is an estimate of how old the body appears based on health and physiological condition, rather than the number of birthdays. The researchers calculated it for every participant from 20 biomarkers, including blood levels of cholesterol, insulin, and C-reactive protein, a standard measure of inflammation.
The results, published in the journal Aging Cell, split cleanly. The omnivorous high-fat group – whose assigned diet most resembled what participants had already been eating – saw no meaningful change. The other three groups all showed reductions in the biological age calculated from their biomarker profiles, with the strongest statistical signal in the omnivorous high-carbohydrate group, whose diet drew 53 percent of energy from carbohydrates and 28 to 29 percent from fat.
“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,” said lead author Caitlin Andrews of the School of Life and Environmental Sciences.
The caveats matter. Four weeks is short, and the team cannot yet say whether the biomarker shifts persist, whether they translate into a lower risk of age-related disease, or whether they appear in younger people. “Longer term dietary changes are needed to assess whether dietary changes alter the risk of age-related diseases,” said Alistair Senior, who supervised the research.
Even so, the finding lands amid a wave of results showing that everyday food choices can measurably reprogram the body – from a major trial where keto outperformed the Mediterranean diet on metabolic health to a blueberry compound that tells muscle cells to burn fat and even the discovery that the scent of dark chocolate can add repetitions to a workout. For now, the simplest takeaway for older adults may be the oldest advice in nutrition – less fat, fewer animal products, more plants – with the honest caveat that the science, much like its participants, is still maturing.
Sources
ScienceDaily: Scientists reversed biological age in older adults in just 4 weeks
University of Sydney (institution)
Featured image: Shixart1985 / Wikimedia Commons, CC BY 2.0.