The Economist: What Britons’ health data reveals about early death risks

Key topics.Genetics play a minor role in longevity, contributing just 3% to mortality.Social connections and mental wellbeing are key to a longer life.Smoking and inactivity significantly increase mortality risk..Sign up for your early morning brew of the BizNews Insider to keep you up to speed with the content that matters. The newsletter will land in your inbox at 5:30am weekdays. Register here..Support South Africa's bastion of independent journalism, offering balanced insights on investments, business, and the political economy, by joining BizNews Premium. Register here..If you prefer WhatsApp for updates, sign up to the BizNews channel here..From The Economist, published under licence. The original article can be found on www.economist.com.© 2025 The Economist Newspaper Limited. All rights reserved..The Economist___STEADY_PAYWALL___.What studying Britons can tell you about the risk factors for an early death.FOR CENTURIES emperors and alchemists searched for an elixir of youth. Today Silicon Valley billionaires pour fortunes into cutting-edge longevity treatments. But the real secrets to a longer life are neither mystical nor high-tech..A study published on February 19th in Nature Medicine, a journal, draws on the UK Biobank, a biomedical database, to see what genetic and environmental factors are most important in helping people age slower, and thus live longer. The UK Biobank contains detailed genetic and medical data from half a million people, as well as information on their income, lifestyle and upbringing. This allowed the authors to disentangle the effects of different factors on disease risk and mortality..Genetics played a surprisingly minor role in overall longevity. Age and sex explained 47% of the variability in mortality, while genetics added just 3% after controlling for these factors (see chart 1). Environmental and lifestyle factors accounted for about 17%. (The remaining variation in mortality cannot be predicted.).Chart: The Economist.The authors then identified the environmental factors with the strongest influence on mortality (see chart 2). Some of the results are obvious: smoking increases a person's risk of premature death by around 60% compared with a non-smoker of the same age, sex and background. Being educated, employed and wealthy were among the most life-extending factors. Physical activity reduced the risk of mortality by roughly 25%..But the study also found that social connections were a surprisingly powerful predictor of a long life. Living with a partner was roughly as beneficial as exercise. Regular visits with family or having someone to confide in also appeared to lower mortality risks. Loneliness is a known risk factor for an early death—people who are socially isolated tend to have greater levels of cellular inflammation and poorer immune responses. It is not clear, however, whether this is a direct effect of being alone, or because lonely people tend to be less active and eat poorer diets..Loneliness also affects mental wellbeing—another factor in longevity. People who reported feeling fed up or unenthusiastic in Biobank surveys were also at higher risk of premature death. Those who reported often feeling tired—which can be a symptom of depression or burn-out—had a 45% greater risk of mortality than more energetic peers. Early childhood experiences had more modest, but lasting effects: Britons who reported being relatively overweight at the age of ten or whose mothers smoked during pregnancy had an increased risk of mortality of 16% and 12%, respectively..Chart: The Economist.Environmental factors matter more for some diseases than others (see chart 3). They explain roughly 35% of the variation of lung and liver disease prevalence, but less for certain cancers, where genetics dominate. Breast cancer, for example, is often caused by a variant of the BRCA2 gene. Brain diseases, such as dementia, also have stronger genetic ties: a variant of the APOE gene greatly increases the risk of developing Alzheimer's..There are caveats to these findings. The study is a lesson in correlation not causation. Installing an open fireplace in your home or gorging on cheese will probably do little to help slow ageing—but both factors were linked to a lower mortality risk (probably because they are also associated with higher wealth in Britain). But the findings do suggest that social connections and mental wellbeing might be just as important as physical exercise in warding off an early death..Read also:.🔒 The Economist: Does intermittent fasting work?🔒 The Economist: Do viruses trigger Alzheimer's?Mental health conditions are medical problems like any other