Longevity Briefs: Environment Is More Important Than Genetics For Mortality

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

Ageing is a complex process influenced by both our genes and the environment we live in. While we know that factors like diet, exercise and stress play a role in how we age, the specific contribution of genetics vs environment is hard to pin down and is still a subject of debate. This new study sheds some more light on the question by suggesting that, encouragingly, environment has a much larger impact for the majority of people.

The discovery:

Researchers analysed data from nearly half a million participants in the UK Biobank, a large-scale biomedical database. Participants were followed for a median of 12.5 years (meaning half of participants were followed for longer than this) to track mortality and disease outcomes. Researchers then looked at the ensemble of environmental exposures a person experiences over their lifetime (referred to as the ‘exposome’) such as diet, physical activity, pollution and socioeconomic factors. They analysed the relationship between the exposome, mortality, and a proteomic ageing clock – an algorithm that estimates biological age based on levels of various proteins in the blood.

They estimated that 17% of the variation in risk of death was explained by environment, while less than 2% was explained by genetics (though this does not include sex). The environmental factors with the greatest impact were smoking, socioeconomic factors, exercise and living conditions. Across all environmental variables found to be associated with biological ageing and mortality, the vast majority were modifiable, with only a few factors like maternal smoking being unmodifiable in adulthood. However, the dominance of environmental factors was not universal, with genetics playing a larger role in certain cancers and forms of dementia.

The implications:

This research is encouraging, suggesting that while genetics set the stage, our environment plays a leading role in determining how we age and when we die. This means that many aspects of ageing are within our control, and lifestyle changes can have a significant impact on health and lifespan. However, it’s important to recognise that the relative contributions of environment and genetics changes throughout life. Genetic factors still appear to play a very important role in reaching exceptional ages of 90 or 100+ years. However, since such individuals are rare, they don’t move the needle much in large studies like this one. With that caveat aside, this study is a reminder that while we can’t change our genes, we can still have a significant influence on how we age by making smart lifestyle choices.