A new study from Oxford Population Health has found that environmental factors like smoking, physical activity, and socioeconomic conditions have a much greater influence on health and premature death than genetics.
The study, published in Nature Medicine, analyzed data from nearly half a million participants in the UK Biobank and revealed that while genes do play a role in some diseases, most health outcomes are shaped by lifestyle and environmental exposures.
Key Findings
- Environmental factors explained 17% of the variation in risk of death, while genetic factors explained less than 2%.
- Smoking, income level, employment status, and physical activity were the most influential factors affecting aging and mortality.
- Smoking was linked to 21 diseases, while socioeconomic factors influenced 19 diseases, and physical activity was connected to 17 diseases.
- Early-life exposures—such as childhood weight and a mother’s smoking habits during pregnancy—can affect health and lifespan decades later.
- Environmental factors had a stronger effect on diseases of the lungs, heart, and liver, while genetics played a bigger role in dementia and breast cancer.
The researchers identified 23 modifiable factors—things that people or governments can change to improve health outcomes. This suggests that making healthier lifestyle choices and improving living conditions could significantly reduce the risk of chronic disease and premature death.
The team used a new method called an “aging clock,” which measures biological aging through blood protein levels. This tool helped them track how quickly people age based on their environment and lifestyle choices.
Dr. Austin Argentieri, the study’s lead author, explained that this approach allowed them to compare the effects of genes and environment more accurately than ever before. “Our findings show that improving our environment and behaviors can significantly reduce the risk of many diseases and early death,” he said.
Professor Bryan Williams, Chief Scientific and Medical Officer at the British Heart Foundation, emphasized the need for government action to address health inequalities. “Your income, postcode, and background shouldn’t determine your chances of living a long and healthy life,” he said.
“This study reinforces that these factors have a major impact on health outcomes.”
While individual choices matter, researchers argue that larger policy changes—such as reducing smoking rates, improving socioeconomic conditions, and promoting physical activity—could have a much broader and lasting impact on public health.
Professor Cornelia van Duijn, one of the senior researchers, highlighted the need for further studies.
“Our study has identified key environmental factors affecting aging and disease, but there are still many unanswered questions,” she said. “We need to better understand the effects of diet, new pathogens like COVID-19, and exposure to chemicals such as pesticides and plastics.”
The study suggests that tracking lifestyle and environmental changes over time, combined with advances in technology and biological data, will be critical to improving health outcomes in the future.
While genetics play a role in some diseases, this study reinforces the idea that our daily choices and living conditions have a much stronger impact on our overall health and lifespan.
The findings suggest that focusing on modifiable risk factors—such as quitting smoking, staying physically active, and addressing socioeconomic disparities—could help reduce the burden of chronic disease and increase life expectancy.
As the researchers note, the power to improve health outcomes lies not just in medical advancements but in the environments we create and the choices we make every day.
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The research findings can be found in Nature Medicine.
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