(AFP) – “Night owls” are no more likely to die younger than early risers who like to get up early in the morning, if they don’t spend their long evenings drinking and smoking, according to a long-term study published on Friday.
Previous work, with data on nearly half a million people in the UK aged 38 to 73, concluded in 2018 that there was a 10% higher risk of death from all causes for diapers. later than for the early birds, over a period of six and a half years.
This British study, the first to explore the risk of mortality, did not take into account factors such as alcohol, which could be involved in these premature deaths.
Researchers wanted to know more and their work was reviewed by peers and published in the specialized journal Chronobiology International.
They tracked nearly 24,000 same-sex twins, this time in Finland, who were asked in 1981 whether they were morning people or evening people. A third described themselves as more of an evening person, 10% as a real evening person, and the others were morning people.
Night owls tended to be younger, but also to drink and smoke more than others. When the researchers took this data, in 2018, more than 8,700 of the twins had died.
Over these 37 years, the researchers estimated that true “night owls” had a 9% higher risk of death from all causes than others. A difference “mainly due to tobacco and alcohol”, according to them: night owls who do not smoke and drink little did not show an increased risk of dying earlier than early risers.
For the study’s lead author, Christer Hublin, of the Finnish Institute of Occupational Health, “truly evening people should think about their alcohol and tobacco use, if they do.”
By itself, regardless of other factors, the time at which individuals tend to go to bed – their “chronotype” – has “little or no” effect on their mortality, he told AFP.
For Jeevan Fernando, a chronotype researcher at the University of Cambridge, the results of this study are solid, but with limits.
Whether participants self-qualified morning or evening is, in his view, “unsatisfactory because it does not provide objective information”, unlike more modern methods.
And the study does not include products other than alcohol and tobacco, points out Jeevan Fernando, author of research showing that “night owls” have worse mental health – mainly with anxiety – and that drug use could exacerbate the problem.