Healthy lifestyle may counterbalance life-shortening genes

Healthy habits can mitigate genetic risks of early death and increase lifespan by five years, a recent study shows.

The influence of both genetic risk factors and lifestyle choices on lifespan is well-documented. However, until now, the extent to which lifestyle choices can counteract the increased risk of death from inherited genetic traits has not been directly studied. Researchers have discovered that while genetic factors alone can increase the risk of premature death by 21 percent, adopting simple healthy habits can reduce this risk by more than half.

'Participants with high genetic risk could prolong approximately 5.22 years of life expectancy at age 40 with a favourable lifestyle,' wrote the authors, from the University of Edinburgh and Zhejiang University School of Medicine in China. 'This study elucidates the pivotal role of a healthy lifestyle in mitigating the impact of genetic factors on lifespan reduction.'

Publishing their findings in BMJ Evidence Based Medicine, the researchers tracked over 350,000 adults from the UK Biobank over 12 years. They evaluated each participant's genetic predisposition to a shorter lifespan using a polygenic risk score based on various genetic markers. A fifth of the participants carried heritable traits that put them at a higher risk of premature death, defined as dying before the age of 75. Participants also received scores based on their lifestyle choices: tobacco smoking, alcohol consumption, exercise habits, body weight, diet, and sleep patterns.

By the end of the 12-year study period, nearly 25,000 participants had died. The researchers then statistically analysed the risk of death, correlating it with the genetic and lifestyle scores for each individual. Their findings indicated that unhealthy habits can significantly shorten lifespan, with the least healthy lifestyles increasing the risk of premature death by 78 percent.

The study concluded that individuals with the highest genetic risk could reduce the risk of early death by 62 percent through straightforward lifestyle changes. The researchers identified an 'optimal lifestyle combination' that includes four key factors: no current smoking, regular physical activity, adequate sleep duration, and a healthy diet.

While the generalisability of this study was limited by a lack of diversity within the cohort – consisting only of participants of white-European heritage from the UK Biobank – the authors hope they could provide evidence to support developing public health policy initiatives around healthy lifestyles.

'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,' the researchers explained. 'Given that lifestyle behavioural habits are usually developed before middle age, taking effective public health interventions is quite crucial for those at high genetic risk to extend their lifespan before the formation of a fixed lifestyle'.