Experts have looked into how nature vs. nurture could influence our health as we age
Does your lifestyle play the biggest role in determining your risk of disease, or do your genes trump all efforts to stay healthy? New research has revealed whether nature or nurture could have a greater impact on living a long and healthy life.
A groundbreaking new study has found that your lifestyle choices could be more powerful than your genetics when it comes to predicting the risk of a number of major diseases and early death.
The largest study of its kind revealed that environmental factors are almost 10 times more important than our genes in influencing the chance of developing 22 conditions, such as cancer, heart disease and liver failure.
These risk factors include things like employment, smoking status, levels of physical activity, and daily hours of sleep. Surprisingly, the amount of cheese you eat could determine if you’re likely to die early – as can whether we live with a partner or frequently ‘feel fed up’.
Experts from the University of Oxford analysed data from nearly half a million people from the UK Biobank, exploring how environmental and lifestyle factors, as well as genetic scores, could be linked to 22 major diseases, including dementia, cancers and chronic diseases of the heart, lungs and liver.
The team found that environmental factors explained 17 per cent of the variation in risk of death, compared to less than 2 per cent explained by a person’s genetic makeup. Genes appeared to play a greater role for dementia and cancers of the bowel, breast, and prostate.
Of the 25 environmental factors identified, smoking, socioeconomic status, physical activity, and living conditions had the most impact on early death and biological ageing. Unsurprisingly, smoking was linked to 21 diseases; household income, home ownership, and employment status, were linked to 19 diseases; and exercise was linked to 17 diseases.
Experts said that the findings show the ‘enormous opportunity for prevention’. 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 researchers worked out how quickly people are ageing based on levels of proteins in their blood – this method is known as a biological ‘age clock’. This data was then correlated with detailed information about their lifestyles and their health information.
The study also found that 23 out of the 25 lifestyle factors were ‘potentially modifiable,’ however some experts claim the ‘modifiable’ factors aren’t entirely within our control. “How do you modify things so that you are living with a partner, if you currently aren’t? (Living with a partner is associated with better health.) How do you modify how often you feel fed up, or how often you feel unenthusiastic? These potential modifications could maybe be done, but saying they are ‘modifiable’ is too much of a simplification,” said Professor Kevin McConway, Emeritus Professor of Applied Statistics, Open University.
Prof McConway also highlights the study is observational, meaning it looked for correlations and associations – not direct causes.
“The statistical methods used by the researchers can’t determine whether the associations between exposures and ill health and mortality, that they observed, are there because the exposures cause the ill health and mortality. They might, or they might not,” Prof McConway added.
That said, some experts have praised the findings for highlighting the importance of our lifestyle choices on our health. “In today’s society, so many are trying to get a quick fix to improve health and longevity, but this study and others are showing the importance of our lifestyle and environment on healthy aging,” said Professor Joyce Harper, Head of the Reproductive Science and Society Group at the UCL Institute for Women’s Health.
“It is the first study to show how the combined effect of individual exposures affects us through the life course. I hope people are listening,” Prof Harper added.
The lead author of the study, Dr Austin Argentieri, research fellow at Massachusetts General Hospital, said the study offered the ‘most comprehensive overview to date’ of how our lifestyle drives ageing and early death.
Commenting on the study, Dr Stephen Burgess, Group Leader at the MRC Biostatistics Unit at the University of Cambridge, warned “genetics can load the dice, but it is up to us how we play our hand.”
Dr Burgess 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.”
The study was published in the journal Nature Medicine.
