Lifestyle choices, living conditions, and other environmental factors have a greater influence on health and premature death than genetic predisposition, researchers from Oxford Population Health revealed.

In a study published in Nature Medicine, the researchers analyzed data from nearly half a million UK Biobank participants to examine the effects of 164 environmental factors and genetic risk scores on aging, age-related diseases, and mortality.

They found that environmental factors accounted for 17% of the variation in death risk, compared to less than 2% linked to genetic predisposition.

Key environmental influences included smoking, socioeconomic status, physical activity, and living conditions.

Smoking was associated with 21 diseases, while socioeconomic factors and physical activity were linked to 19 and 17 diseases, respectively.

The researchers also noted that early life exposures, such as body weight at age 10 and maternal smoking, affected aging and premature death decades later.

The study also found that environmental factors significantly impacted lung, heart, and liver diseases, whereas genetic risks were more influential for dementia and breast cancer.

"While genes play a key role in brain conditions and some cancers, our findings highlight opportunities to mitigate the risks of chronic diseases of the lung, heart, and liver which are leading causes of disability and death globally," said Professor Cornelia van Duijn, St. Cross Professor of Epidemiology at Oxford Population Heath and senior author of the paper.

"The early life exposures are particularly important as they show that environmental factors accelerate aging early in life but leave ample opportunity to prevent long-lasting diseases and early death," she added.

The authors used a unique measure of aging or a new "aging clock" to monitor biological aging through blood protein levels, connecting environmental exposures to early mortality.

"Studies on environmental health have tended to focus on individual exposures based on a specific hypothesis," Professor van Duijn said.

"While this approach has seen many successes, the method has not always yielded reproducible and reliable findings. Instead, we have followed a 'hypothesis free' exposome approach and studied all available exposures to find the major drivers of disease and death," she added.

The research was conducted by Oxford Population Health in collaboration with international institutions, including the University of Oxford, Massachusetts General Hospital, and the University of Amsterdam, with technical support from the China Kadoorie Biobank team. #

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