Healthy ageing is often framed as a product of lifestyle: diet, exercise, and sleep. But new research suggests that genetics plays a substantial role in determining how well people age, accounting for up to a quarter of the differences in physical and mental function later in life.
A study from the University of Adelaide has found that genetic predisposition contributes between 19.5 and 25.2 percent of the variation in what researchers call “intrinsic capacity,” a key measure of healthy ageing.
“Our findings show that genetics plays a significant role in shaping human intrinsic capacity—the set of physical and mental abilities that underpin healthy ageing,” Associate Professor Azmeraw Amare told The Epoch Times.
The findings point to a model of ageing that is influenced by genetic disposition, lifestyle, environmental choices, and the complex interactions between them.
Intrinsic Capacity and What the Research Found
Central to the study is the concept of “intrinsic capacity.”
Unlike traditional metrics that measure the presence of disease or simple lifespan, intrinsic capacity tracks a person’s overall physical and mental abilities, including mobility, cognitive function, and psychological well-being.
Using data from over 13,000 participants in the Canadian Longitudinal Study on ageing, researchers analysed how genetic predisposition and lifestyle behaviours—such as physical activity, diet, sleep, and smoking—interacted to shape these outcomes.
The results concluded that higher intrinsic capacity was associated with greater physical activity, a Mediterranean-style diet, higher educational attainment, employment, and social engagement.
Conversely, suboptimal sleep—less than 7 hours or more than 9 hours—and smoking contributed to lower intrinsic capacity.
Why Genetics Isn’t Destiny
One of the study’s most compelling takeaways is that genetics and lifestyle do not operate in isolation.
According to Amare, your DNA can act as a “volume knob” for your lifestyle choices.
“Genetic predisposition can either amplify or buffer the effects of lifestyle and behavioral factors on ageing outcomes,” he said.
This means that even among individuals with similar habits, aging outcomes may differ depending on their genetic makeup.
Despite the influence of genetics, the research stresses that lifestyle factors are modifiable and are influential in shaping how people age.
“People who engaged in regular physical activity, maintained a nutritious diet, followed recommended sleep durations, and avoided smoking had significantly higher intrinsic capacity, independent of genetic background,” Amare said.
The study also found a clear “dose-response” relationship, where individuals who consistently followed healthy behaviors gained improvements to their intrinsic capacity and key biological systems.
“These factors likely influence intrinsic capacity through their effects on energy metabolism, cardiovascular and neuromuscular function, and brain health,” Amare said.
Relevance to Australia and Diverse Communities
Though the study is based on Canadian data, Amare said the findings were broadly applicable to Australia.
“Both populations are primarily of European ancestry and share similar socioeconomic and lifestyle patterns typical of Western societies,” Amare said. “These similarities make the general conclusions relevant for Australians.”
However, he noted a caveat—there is a critical need for more diverse data.
“It’s important to recognise that non-European and culturally diverse populations remain underrepresented in this research,” Amare said.
“Future studies within Australian cohorts, especially those reflecting culturally and linguistically diverse communities, will be crucial to confirm and broaden the applicability of these findings.”
While genetics may set the parameters of our potential, lifestyle remains the most practical and accessible way to improve how we age.
The research supports a shift toward personalized preventive health, where one day, your exercise and diet plan could be tailored to your specific genetic “buffer.”