Is Loneliness Cutting Your Life Short?

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. Environmental and lifestyle factors accounted for about 17%. (The remaining variation in mortality cannot be predicted.)

The authors then identified the environmental factors with the strongest influence on mortality. 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.