PARIS, June 16, 2023 (BSS/AFP) - People who tend to stay up late are not more
likely to die younger than early risers -- as long as they don't use those
longer nights for drinking and smoking, a 37-year-long study suggested on
Friday.

Previous research has shown that night owls, who stay up later and struggle
to drag themselves out of bed in the morning, are more likely to suffer from
a range of health problems.

In 2018, a large study in the UK found that evening people had a 10 percent
higher risk of dying than morning people over a 6.5-year period.

While that was potentially worrying news for the world's night owls, that
research did not take into account factors, such as alcohol-consumption, that
could be behind those deaths.

So researchers in Finland sought to find out more in a study published in the
peer-reviewed journal Chronobiology International.

The study followed nearly 24,000 same-sex twins in Finland, who were asked in
1981 to identify whether they were a morning or an evening person.

A third said they were somewhat an evening person, while 10 percent said they
definitely were. The rest were morning people.

The evening people tended to be younger, and tended to drink and smoke more.

When the researchers followed up in 2018, more than 8,700 of the twins had
died.

Over the 37 years, the researchers found that the definite night owls had a
nine percent higher risk of death from all causes -- a similar rate to the
2018 study.

But that difference was "mainly due to smoking and alcohol", the study said.

For example, it found that non-smoker night owls who were light drinkers were
no more likely to die earlier than morning people.

- Night owls and drugs -

The study's lead author, Christer Hublin of the Finnish Institute of
Occupational Health, told AFP the results showed that night owls can act if
they want to lower their risk of an early death.

"Clearly evening people should critically think about the amount of alcohol
and tobacco they are using," he said.

Independent of other factors, the time when people tend to sleep, known as
their chronotype, has "little or no" contribution to their mortality, Hublin
added.

Jeevan Fernando, a chronotype researcher at Cambridge University not involved
in the study, told AFP that while the findings were sound, the research had
limitations.

That participants merely self-identified as morning or evening people was
"unsatisfactory because it does not include any objective information" unlike
more modern methods, he said.

The study also failed to include drugs other than alcohol and tobacco, he
said: cocaine in particular had been linked to people changing from early to
late risers.

Fernando has previously led research that showed night owls have worse mental
health -- particularly anxiety -- and that drug use could exacerbate the
problem.