Healthy Ageing: How Genetics & Lifestyle Interact

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 highlights the complex relationship between genetics and lifestyle, suggesting that genetic predisposition can shape how strongly factors like diet and sleep influence healthy ageing.

Understanding Intrinsic Capacity

The research, the first of its kind, shows that diet, physical activity, sleep, smoking, education, employment and social engagement all influence how people 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. This metric serves as a proxy indicator of healthy ageing, reflecting the life-long ability to physiologically adapt to intrinsic and external stressors to minimize frailty.

Using data from more than 13,000 participants in the Canadian Longitudinal Study on Ageing, the researchers analyzed how various modifiable factors interacted with genetic profiles. The findings indicate 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.

The Role of Genetics and Sleep

Associate Professor Azmeraw Amare from the University of Adelaide’s School of Medicine emphasized the nuanced interplay discovered in the data. He noted that intrinsic capacity is influenced by a complex interplay between genetics and modifiable socioeconomic and lifestyle factors. The study found that genetic predisposition can shape how strongly these factors influence healthy ageing.

Specific attention was paid to sleep duration. The study 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. However, long sleep appeared to have a stronger negative effect in middle-aged adults, even among those with favourable genes. This suggests that while genetics provide a baseline, they do not fully protect against the consequences of certain lifestyle choices.

Diet and Education as Buffers

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. This suggests that lifestyle and social factors may become increasingly important as people age, potentially offering a pathway to mitigate genetic risks over time.

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.

Professor Renuka Visvanathan, University of Adelaide

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. 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.

Broader Context on Genes and Lifestyle

These findings align with broader medical understanding regarding the interaction between genetics and environment. According to WebMD, genes can raise the risk for many diseases, but they do not typically work alone. It is rarely a single gene that determines whether a person will get a disease. Instead, individuals often inherit genetic characteristics that make them more likely to get a disease, which might not affect them at all unless triggered by environmental factors or lifestyle.

This phenomenon is often described through epigenetics, where lifestyle or environmental factors cause a particular gene to turn on or off. For instance, epigenetic changes might turn on a gene that enables abnormal cells to grow or turn off a gene that would suppress their growth. This supports the University of Adelaide’s finding that modifiable factors can influence outcomes even in the presence of genetic predispositions.

Further context provided by the Mayo Clinic indicates that while factors interact with genes to influence life and health, lifestyle and environment often hold greater weight in the aging process. This reinforces the significance of the Adelaide study’s conclusion that socioeconomic and lifestyle factors remain critical levers for health promotion, regardless of genetic starting points.

Implications for Public Health

The research underscores the importance of targeted health promotion strategies. Professor Renuka Visvanathan, an expert in Geriatric Medicine at the University of Adelaide, added that the findings could help shape these strategies. By understanding how genetic predisposition shapes the influence of lifestyle factors, health officials can better support independence and quality of life across adulthood and later life.

Healthy aging represents the life-long ability to physiologically adapt to intrinsic and external stressors to minimize frailty in aging and maximize resilience in older age. The continuum of allostatic load represents a combination of genetic and environmental factors that can, in some cases, have life-long consequences. As the research team moves forward, their goal is to translate these observational findings into clinical and public health strategies that target modifiable lifestyle factors to promote healthy longevity.