| The debate over whether nature or nurture is more likely to cause an untimely death has been tilting toward nurture for quite some time. Exercise, smoking and even factors like loneliness have all been linked to life expectancy. But this week, one new study showed just how strong those links may be, while another hinted at the impact they might have had on a population level in Norway. In the first, published in Nature Medicine, a University of Oxford and Harvard University team delivered the most definitive comparison yet of a whole palette of environmental factors — what’s called an “exposome” — with genetic risk. Using the UK Biobank, a database of about 500,000 people in England, Scotland and Wales, they found the external factors were almost 10 times more likely than genetic risk to explain premature death. “We were surprised at just how stark the difference was,” says Austin Argentieri, a researcher in the analytic and translational genetics unit at Massachusetts General Hospital. The difference came in particular in diseases of the lung, heart and liver (genetic risk was in play for dementia and certain cancers). The second study, funded by the Gates Foundation and published in The Lancet Public Health, showed that in most countries in Europe, gains in life expectancy slowed down after 2011. England performed particularly poorly. But in Norway, where authorities have sought to reduce inequality and taken a harder line on factors such as sugar and salt in foods, gains in life expectancy continued to advance. The Nordic country’s stricter approach may have been more successful than voluntary and education-based programs in England and Scotland, says Nick Steel, a professor at the University of East Anglia’s Norwich Medical School, who led the study. “It’s those underlying causes that we would like governments to tackle,” he says. In the genetics versus environment study, because the people being surveyed were all from the UK, researchers cautioned that some results might not quite translate to other countries. For example, eating cheese was associated with a lower risk of early death. That could be because “cheese-eating is also quite related to socio-economic status,” says Cornelia van Duijn, an Oxford professor of epidemiology who helped lead the study. Another factor, heating your house with an open flame, probably also has a class twist: a working fireplace would be a more likely feature if you’re living in a grand home in the English countryside. But some of the factors are certainly things governments could address, says Aimee Aubeeluck, a professor of health psychology at the University of Surrey, who reviewed the study for the Science Media Centre. That could mean treating things like maternal smoking “with the same urgency as genetic therapies,” she argues. It could also mean tackling pollution and giving people access to green space, Aubeeluck says. Sounds a little like Norway. — Naomi Kresge | 
