Older Australians who cut back on either dietary fat or animal protein show signs of reduced biological age, new research from the University of Sydney shows.
Posted on Aging cellfindings revealed that 65 to 75-year-olds who underwent a nutritional intervention for just four weeks experienced a reduction in their “biological age” based on their biomarker profile. Led by Dr Caitlin Andrews from the University of Sydney’s School of Life and Environmental Sciences, the research highlights the potential for nutritional interventions to rapidly improve health and aging outcomes in older age. It offers a preliminary indication rather than a definitive result, with the authors calling for longer-term trials to test whether these improvements translate into reduced disease risk and whether the findings extend to other age groups.
While chronological age increases uniformly, biological aging varies among individuals, reflecting differences in health status and the resilience of the organism. Scientists can estimate biological age using biomarker profiles, measures of physiological function over time that are often considered a better indicator of overall health and potential longevity than chronological age.
The research incorporated data from 20 different biomarkers — including blood levels of cholesterol, insulin and C-reactive protein — to calculate a biological age score for participants in the Nutrition for Healthy Living study, conducted at the University’s Charles Perkins Center.
In the Nutrition for Healthy Living study, 104 participants were randomly assigned to one of four diets, each of which derived 14 percent of energy from protein. Two were omnivores (half came from animal sources and the rest from plants) and two were semi-vegetarians (with 70 percent of protein coming from plant sources). Within the omnivore and semi-vegetarian categories, participants were assigned to either high-fat, low-carbohydrate or low-fat, high-carbohydrate diets, resulting in four diet categories: omnivore high-fat (OHF), omnivore high-carbohydrate (OHC), semi-vegetarian high-carbohydrate (HCFmi-High-Fat)
Participants’ BMI (body mass index) ranged from 20-35. All participants were non-smokers, non-vegetarians, and free of major complications (eg, type 2 diabetes, cancers, kidney or liver disease) or food allergies and/or intolerances.
The OHF group, whose modified diets most closely resembled participants’ baseline diets, showed no significant change in the “biological age” of their biomarker profile. However, the biological age of the biomarker profile for the remaining three groups showed decreases. The reduction in biological age among the OHC group – those who ate high-carbohydrate omnivorous diets – was estimated with the highest degree of statistical confidence. This group’s diet consisted of 14 percent of energy from protein, 28-29 percent from fat, and 53 percent from carbohydrates.
It is unclear whether the impact of dietary changes on age-related biomarker profiles is durable and leads to lasting biological reversal of age.
Long-term dietary changes are needed to assess whether dietary changes alter the risk of age-related diseases.”
Alistair Senior, Associate Professor, School of Life and Environmental Sciences and Charles Perkins Center
“It’s too early to say definitively that specific dietary changes will extend your life. But this research offers an early indication of the potential benefits of dietary changes later in life,” said Dr Andrews.
“Future research should investigate whether these findings extend to other cohorts and whether the changes recorded are sustained or predictive of long-term outcomes.”
