- International study sorts out how much of disease risk is tied to genes and how much to lifestyle.
- Socioeconomic factors like where you live, household income influence premature death risk.
- Of the factors that increase risk of aging badly, most can be changed.
Is your ZIP code more important than your genetic code when it comes to having a long, healthy life?
Genetics and lifestyle both contribute to how people age, the diseases they develop and how long they’re likely to live. But the role the factors play and how much they influence disease development and premature death might surprise you.
Socioeconomics and lifestyle have more to do with healthy aging than genetics, according to a big new international study published in the journal Nature Medicine that says both lifestyle choices and living conditions are significantly more important than genetics to living a long, healthy life.
According to the study, of 25 independent exposures associated with premature death, age-related diseases and healthy aging, “We find that the major drivers or premature death and aging in our sample are smoking, socioeconomic status and deprivation, ethnicity, physical activity, living with a partner, sleep and mental and physical wellness including tiredness, as well as early life exposures including health and body size at 10 years and maternal smoking around birth.”
They note that many factors combine to form the “environmental architecture of mortality and aging,” and each may play a very small role, but adding them up creates a “substantial amount of variation for premature mortality, far exceeding” that posed by genetic risk.
“Your income, postcode and background shouldn’t determine your chances of living a long and healthy life,” Bryan Williams, chief scientific and medical officer at the British Heart Foundation, said in a news release. “But this pioneering study reinforces that this is the reality for far too many people.”
Study nuts and bolts
The study was led by researchers from Oxford Population Health in collaboration with researchers from the departments of psychiatry and anthropology at the University of Oxford; Massachusetts General Hospital and the Broad Institute, Boston; the University of Amsterdam; Erasmus University, Rotterdam; and the University of Montpellier. They also got technical help from the China Kadoorie Biobank team.
The data researchers used included extensive genetic and phenotype information on 502,505 people who were participants in UK Biobank research and data collection. They looked at 164 environmental facts and genetic risk scores for 22 major diseases.
A key part of the research was an “aging clock” that used blood protein levels to see how fast people aged. “This enabled them to link environmental exposures that predict early mortality with biological aging,” the team said in background material on the study. The measure has also been validated in large studies in China and Finland.
Cornelia van Dujin, St. Cross professor of epidemiology at Oxford Population Health and the paper’s senior author, noted that instead of focusing on individual exposures and hypotheses, they used a hypothesis-free, lifetime exposure approach to see what drives disease and death.
Genes vs. lifestyle
Among the findings:
- Environmental factors explained 17% of the death risk variation, while genetic predisposition “as we understand it at present” explained just 2%.
- Of the 25 environmental factors, those with the most impact on healthy or unhealthy aging were smoking, socioeconomic status, physical activity and living conditions.
- Smoking was linked to 21 diseases, while socioeconomic factors like household income, employment and home ownership were linked to 19 diseases. Physical activity impacted 17.
- Of the factors, 23 could be changed.
- Early life exposures, including whether your mother smoked around the time of your birth and your body weight at 10 years old, influenced aging and risk of death decades later.
- Environmental exposure had greater effect on lung, heart and liver disease, while genetic risk was stronger for dementias and breast cancer.
“Our research demonstrates the profound health impact of exposures that can be changed either by individuals or through policies to improve socioeconomic conditions, reduce smoking, or promote physical activity. 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 van Dujin.
She added, “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.”
Dr. Austin Argentieri, lead author of the study at Oxford Population Health and research fellow at Massachusetts General Hospital, said the approach they used made the research the “most comprehensive to date of the environmental and lifestyle factors driving aging and premature death. These findings underscore the potential benefits of focusing interventions on our environments, socioeconomic contexts and behaviors for the prevention of many age-related diseases and premature death.”
