Healthy lifestyle could offset genetic risk factors and extend lifespan

Adopting a healthy lifestyle could potentially counteract the effects of genes that may shorten the lifespan by around 60%, according to an new analysis.

The study, published in BMJ Evidence Based Medicine, found that regardless of genetic predisposition, an unhealthy lifestyle independently increases the risk of premature death by 78%.

The authors say the study highlights the need for public health policies which encourage healthy living to reduce the burden on healthcare services.

Participants given polygenic risk score and asked about lifestyle factors

Researchers used data from the UK Biobank study to analyse over 350,000 adults. The participants were recruited between 2006 and 2010 and followed up until 2021.

A polygenic risk score (PRS), which combines multiple genetic variants to arrive at a person’s overall genetic predisposition to a longer or shorter lifespan, was derived for each of the participants.

In total 20% were considered likely to have a long lifespan, 60% an intermediate lifespan, and 20% a short lifespan.

To assess their lifestyle, participants were asked whether they smoke, their alcohol consumption, how often they exercise, their diet, the quality of their sleep and their body shape. They were then categorised into favourable (23% of participants), intermediate (56%), and unfavourable (22%) lifestyles.

Over the 13 year follow up period, just over 24,200 participants died.

Adopting a healthy lifestyle could extend life expectancy by five or more years by the age of 40

The researchers found that those with genetic predispositions to a shorter life were 21% more likely to die prematurely, regardless of lifestyle. Individuals with unfavourable lifestyles faced a 78% higher risk of premature death, irrespective of genetics.

The combination of high genetic risk and an unfavourable lifestyle doubled the risk of premature death compared to those with low genetic risk and a favourable lifestyle.

Four factors, including not smoking, regular exercise, sufficient sleep, and a healthy diet, emerged as crucial components of an optimal lifestyle.

The authors of the study acknowledge various limitations to their study, including its observational nature, that all participants were of European ancestry (limiting is generalisability) and that lifestyle was only assessed at one point in time.

Even so, they suggest that adopting a healthy lifestyle could mitigate genetic risks, potentially extending life expectancy by around 5.5 years by age 40.

“This study elucidates the pivotal role of a healthy lifestyle in mitigating the impact of genetic factors on lifespan reduction,” they conclude. “Public health policies for improving healthy lifestyles would serve as potent complements to conventional healthcare and mitigate the influence of genetic factors on human lifespan.