While genes and lifestyle interact to influence lifespan, it’s crucial to note that an unhealthy lifestyle can independently elevate the risk of premature death by a staggering 78%, regardless of genetic predisposition. This striking finding from recent research, which utilised a polygenic risk score (PRS) to assess genetic predisposition across 353,742 adults from the UK Biobank, tracked from 2006 to 2021, underscores the urgent need for healthier habits. Lifestyle factors such as tobacco use, alcohol consumption, diet, sleep, and physical activity were also evaluated in the study.
The findings suggest that individuals genetically predisposed to a shorter lifespan faced a 21% higher risk of early death compared to those with genetic advantages for longevity, regardless of lifestyle choices. Similarly, those with unfavourable lifestyles were 78% more likely to die prematurely than their counterparts with healthier habits, independent of genetic factors. Those at high genetic risk and with unhealthy lifestyles were twice as likely to die early compared to those with low genetic risk and healthy lifestyles.
The study identified four critical components of an optimal lifestyle: non-smoking, regular physical activity, sufficient sleep, and a healthy diet. These factors collectively contributed to mitigating genetic predispositions to shorter lifespans by approximately 62%. Importantly, the study found that individuals at high genetic risk could extend their life expectancy by up to 5.5 years at age 40 by adopting a healthy lifestyle. This positive message underscores the potential for positive change and encourages individuals to make healthier choices.
The researchers acknowledge limitations, including the study’s observational nature, which precludes definitive cause-and-effect conclusions. Lifestyle assessments were conducted only once, and the study population consisted predominantly of individuals of European ancestry, which may limit generalisability. Despite these constraints, the findings underscore the critical role of healthy lifestyles in offsetting genetic risks for lifespan reduction.
The study emphasises the importance of public health policies promoting healthy lifestyles as complements to conventional healthcare. By encouraging healthy habits earlier in life, these policies could mitigate the impact of genetic factors on lifespan and promote longer, healthier lives.
More information: Zilong Bian et al, Genetic predisposition, modifiable lifestyles, and their joint effects on human lifespan: evidence from multiple cohort studies, BMJ Evidence-Based Medicine. DOI: 10.1136/bmjebm-2023-112583
Journal information: BMJ Evidence-Based Medicine Provided by BMJ Group
