A new international study led by researchers at the University of Adelaide has found that while lifestyle and socioeconomic factors play a major role in healthy ageing, their effects can vary depending on a person’s genetic makeup.
The research, the first of its kind, shows that diet, physical activity, sleep, smoking, education, employment and social engagement all influence how we age — but not equally for everyone. The study focused on “intrinsic capacity,” a measure that combines physical and mental abilities needed to maintain independence and perform daily tasks throughout life.
Using data from more than 13,000 participants in the Canadian Longitudinal Study on Ageing, the researchers found that people who were more physically active, ate a better-quality diet, had higher education levels, were employed, and stayed socially engaged tended to age more healthily. In contrast, smoking and poor sleep — whether too little or too much — were linked to lower intrinsic capacity, meaning reduced physical and mental function with age.
Associate Professor Azmeraw Amare from the University of Adelaide’s School of Medicine said the findings highlight the complex relationship between genetics and lifestyle. “Intrinsic capacity, a proxy indicator of healthy ageing, is influenced by a complex interplay between genetics and modifiable socioeconomic and lifestyle factors,” he said. “Our findings suggest that genetic predisposition can shape how strongly these factors influence healthy ageing.”
The study also found that both short and long sleep durations were harmful to healthy ageing. Interestingly, people with a genetic advantage for intrinsic capacity were less affected by short sleep, but long sleep appeared to have a stronger negative effect in middle-aged adults, even among those with favourable genes.
Following a Mediterranean-style diet and achieving higher education were found to be particularly beneficial, even for those with a lower genetic predisposition for healthy ageing. The researchers noted that genetic effects were more pronounced in midlife than in later years, suggesting that lifestyle and social factors may become increasingly important as people age.
PhD candidate Melkamu Bedimo Beyene, the study’s first author, said this is the first research to show how genes interact with modifiable lifestyle factors such as diet, education and sleep to influence intrinsic capacity. Professor Renuka Visvanathan, an expert in Geriatric Medicine at the University of Adelaide, added that the findings could help shape more targeted health promotion strategies. “By focusing on maintaining functional ability rather than waiting for disease to develop, we can better support independence and quality of life across adulthood and later life,” she said.
The study was published in The Journals of Gerontology: Biological Sciences. The research team now plans to explore clinical and public health strategies that target modifiable lifestyle factors to promote healthy longevity and prevent functional decline.