Nurture plays a greater role than nature in our risk of a number of major diseases and premature death, according to a new study.
Oxford Uni researchers who assessed the influence of 164 environmental factors and genetic risk scores for 22 major diseases found environment explained 17% of the variation in death risk, compared to less than 2% explained by genetic predisposition.
Factors such as smoking, socioeconomic status and physical activity had the most impact. Gym use, cheese consumption and nap frequency can also play a role, the study found.
Living conditions were also important, including whether or not someone lives with a partner, their household income and whether or not people use an open fire for heating.
Even someone’s weight at the age of 10 can influence ageing and risk of premature death 30 to 80 years later, along with other early life exposures such as a mother smoking around the time of a child’s birth. Experts said that the study showed the “enormous opportunity for prevention”.
Senior author Professor Cornelia van Duijn, from Oxford Population Heath, said: “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.
“The early life exposures are particularly important as they show that environmental factors accelerate ageing early in life but leave ample opportunity to prevent long-lasting diseases and early death.”
The study used data from more than one million people enrolled in the UK Biobank.
Researchers assessed how quickly people were ageing biologically based on levels of proteins in their blood – this method is known as an “age clock” which monitors how rapidly people are ageing using blood protein levels.
This was then correlated with detailed information about their lifestyles and their health information.
When looking at specific disease, they found that environmental factors appeared to have more influence than genes on diseases of the lung, heart and liver.
And genetic factors appeared to play a greater role than the environment for dementia and cancers of the breast, prostate and bowel.
Dr Austin Argentieri, who led the work at Oxford Population Health and is a research fellow at Massachusetts General Hospital, said the study provides the “most comprehensive overview to date of the environmental and lifestyle factors driving ageing and premature death”.
He added: “These findings underscore the potential benefits of focusing interventions on our environments, socioeconomic contexts, and behaviours for the prevention of many age-related diseases and premature death.”
Dr Stephen Burgess, group leader at the MRC Biostatistics Unit at the University of Cambridge, said the research showed that “genetics can load the dice, but it is up to us how we play our hand”.
He added: “There are exceptions, including rare conditions that are caused by a single genetic variation, but for the majority of conditions that Western people die from, disease risk is more strongly attributable to modifiable risk factors and our wider environment, as shaped by our upbringing and choices.
Professor Bryan Williams from the British Heart Foundation, said: “Your income, postcode and background shouldn’t determine your chances of living a long and healthy life.
“But this pioneering study reinforces that this is the reality for far too many people.”