Scientists have used data from almost half a million people in the UK Biobank to investigate an old question - is nature (or our genes), or nurture (environmental factors) a greater contributor to our health and longevity? This research has suggested that environmental factors and habits like living conditions, physical activity levels, and smoking have a larger impact on our health and early death than genes do.
In this study, the investigators considered a total of 164 environmental factors and calculated genetic risk scores for 22 major diseases, and how they affected age-related diseases, aging, and premature death. These environmental factors could explain about 17% of variation in death risk, while genetic predispositions could only explain 2% of that risk. The environmental factors that contributed the most to mortality and aging were smoking, socioeconomic status, physical activity, and living conditions. The findings were reported in Nature Medicine.
These environmental characteristics had a greater effect than lung, heart, or liver disease genetic risk factors, but genetic risk was a larger contributor to dementia and breast cancer. The researchers were also relying on the genetic risk factors that have currently been identified; there may be others that have not yet been revealed and which might increase genetics' contribution to mortality or aging.
However, the study also highlights that many of these significant environmental conditions are modifiable habits, such as smoking or exercise. It also stresses the importance of creating equitable living standards.
"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 aging early in life but leave ample opportunity to prevent long lasting diseases and early death," noted senior study author Professor Cornelia van Duijn, a Professor at Oxford Population Heath.
To measure biological aging for this study, the researchers used blood protein markers, which predict early mortality. This method has been used in other aging studies.
'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," added Professor Bryan Williams, Chief Scientific and Medical Officer at the British Heart Foundation.
Sources: Oxford University, Nature Medicine
