Nurture is more influential than nature when it comes to number of major diseases and premature death, according to a new study.
Environmental factors are almost 10 times more important than genetic factors when it comes to a person’s risk of death from a number of serious diseases, according to one of the largest studies of its kind.
And many of the environmental risk factors for disease can be modified, researchers said.
The fact that most of the risk factors identified are modifiable highlights an enormous opportunity for prevention
These include employment, smoking status, levels of physical activity, and hours of sleep per day.
Gym use, cheese consumption and nap frequency can also play a role, the study found.
Living conditions are 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 shows the “enormous opportunity for prevention”.
Researchers led by academics from the University of Oxford wanted to assess how ageing and mortality is impacted by genes and the environment.
They studied data on almost half a million people taking part in the UK Biobank study – a large study tracking hundreds of thousands of people from across the UK.
Genetics can load the dice, but it is up to us how we play our hand.
The researchers assessed how quickly people are 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.
The study, published in the journal Nature Medicine, found that environmental factors explained 17% of the variation in the risk of death, compared with less than 2% by genetic predisposition.
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.
Researchers said that of the 25 environmental factors identified, smoking, socioeconomic status, physical activity, and living conditions had the most impact on mortality and biological ageing.
And 23 out of the 25 factors were “modifiable”.
While many of the individual environmental factors played a small part in premature death, the combined effect of these multiple factors together explained a large proportion of premature mortality variation, the researchers found.
Senior author of the paper, 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.”
Dr Austin Argentieri, lead author of the study at Oxford Population Health and 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,” adding: “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.”
Commenting on the study, 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.”
Felicity Gavins, professor of pharmacology at Brunel University of London, added: “This is an exciting study. The fact that most of the risk factors identified are modifiable highlights an enormous opportunity for prevention.
“By addressing social inequalities, promoting healthy behaviours and reducing harmful exposures, we can really make a meaningful difference in reducing age-related diseases and premature mortality.”
Dr Stephen Burgess, group leader at the MRC Biostatistics Unit at the University of Cambridge, said: “This is a large and detailed investigation into the predictors of major causes of mortality in a UK-based population.
“It provides further demonstration supporting previous research that, in the majority of cases, our genes do not determine our future.
“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.
“Genetics can load the dice, but it is up to us how we play our hand.”
