Healthcare (Commonwealth Union) – The recognition of the role of diet in health has been more and widely accepted from researchers across the world. A recent study from the University of Sydney, Australia suggests that older Australians who cut back on either dietary fat or animal-based protein may experience a decrease in their biological age.
Published in Aging Cell, the study found that participants aged 65 to 75 who followed a dietary intervention for just four weeks exhibited a lower ‘biological age’ according to their biomarker profiles. The research, led by Dr Caitlin Andrews from the University of Sydney’s Charles Perkins Centre and School of Life and Environmental Sciences, shows the potential for short-term changes in diet to rapidly improve health and ageing outcomes in older adults. The findings are preliminary, not final, and the researchers say longer-term studies are needed to determine if those changes lower disease risk and if similar effects happen in other age groups.
Biological age versus chronological age is an important consideration for the research, because biological ageing varies between individuals, reflecting differences in health and resilience of the body, whereas chronological age advances at the same rate for everyone. Scientists have developed the ability to estimate biological age from biomarker profiles—measurements of physiological function over time—that are often thought to be a more accurate measure of overall health and longevity potential than chronological age alone.
For this study, researchers combined 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 University’s Nutrition for Healthy Living study conducted at the Charles Perkins Centre.
Dietary adjustments and biological age were key factor researchers took into account. In the Nutrition for Healthy Living study, 104 participants were randomly allocated to one of four dietary plans, each providing 14% of total energy from protein. Two of the diets were omnivorous, with protein split evenly between animal and plant sources, and the other two were semi-vegetarian, with about 70% of the protein coming from plant-based foods.
Within both the omnivorous and semi-vegetarian groups, participants were also divided into high-fat, low-carbohydrate diets or low-fat, high-carbohydrate diets. This led to four different dietary patterns: omnivorous high-fat (OHF), omnivorous high-carbohydrate (OHC), semi-vegetarian high-fat (VHF) and semi-vegetarian high-carbohydrate (VHC).
All participants were non-smokers with a body mass index (BMI) between 20 and 35.
None followed strict vegetarian diets, and all were free from major health conditions such as type 2 diabetes, cancer, kidney or liver disease, as well as any significant food allergies or intolerances.
Results showed that the OHF group—whose modified diet most closely matched their usual eating habits—experienced no significant change in biological age based on biomarker analysis. In contrast, the other three groups all showed reductions in biological age. The most statistically robust decrease was observed in the OHC group, which followed an omnivorous, high-carbohydrate diet consisting of 14% protein, about 28–29% fat, and roughly 53% carbohydrates.
Researchers of the study indicated that it remains uncertain whether dietary changes have a lasting effect on age-related biomarker profiles and lead to long-term reductions in biological age.
The Associate Professor Alistair Senior, from the School of Life and Environmental Sciences and the Charles Perkins Centre, who was responsible for supervising the study says “Longer term dietary changes are needed to assess whether dietary changes alter the risk of age-related diseases.”
Dr Andrews stressed that it is too soon to determine definitively that specific alterations in diet will be responsible for longer life. She indicated however however that this study provides an early indication of the possible advantages of dietary alteration in life later on.
“Future research should explore whether these findings extend to other cohorts and whether the changes recorded are sustained or predictive of long-term outcomes.”
