Summary: People who naturally stay up late,
so-called “night owls”, are more likely to experience faster cognitive
decline than those who are early risers, according to a long-term study.
Researchers found that unhealthy behaviors common in the evening, such
as poor sleep, smoking, and drinking, may explain part of this risk.
The
study showed that 25% of cognitive decline could be linked to these
habits, especially among higher-educated individuals who often face
early work schedules that clash with their natural rhythms. While
chronotype is largely genetic, aligning daily routines with one’s
biological clock may help protect long-term brain health.
Key Facts:
- Chronotype Matters: Evening types showed faster cognitive decline over 10 years.
- Behavioral Link: Risk is partly explained by more smoking, drinking, and poor sleep.
- Lifestyle Tip: Working against your natural sleep rhythm may worsen brain health.
Source: UMCG
Are you a morning or an evening person?
Those
who stay up at night and go to bed late are more likely to suffer
cognitive decline than morning people, UMCG research shows.
‘The
good news is that you can partly influence this cognitive decline by
adjusting your behaviour,’ says researcher Ana Wenzler, whose research
contributes to dementia prevention.
Because we are getting older, there are more and more people with
dementia. Within a large national study, the BIRD-NL project, the UMCG,
together with many partners, is researching ways to prevent dementia.
‘The
fact is that your brain deteriorates after the age of 40, says Wenzler.
‘We study which lifestyle or other factors can reduce the risk of
dementia.’
What is your chronotype?
Wenzler’s area of research is sleep.
‘Using
Lifelines data, I look at people’s sleep rhythms. Are you an early bird
or a night owl? It’s hard to adjust what your biological clock – your
so-called chronotype – is, but you can adjust your life to it as best
you can. In my research, I looked at whether your chronotype affects
your cognition through behavior.’
Based on questionnaires that
Lifelines participants filled in about their sleep times, Wenzler was
able to determine the extent to which people are extreme early or late
sleepers, and everything in between.
She
then looked at the results of a cognitive function test over a 10-year
period: how did early scores differ from scores 10 years later?
More frequent unhealthy behaviour in the evening
The conclusion: evening people decline cognitively faster than morning people.
‘Unhealthy behavior such as smoking, drinking and unhealthy eating happens more often in the evening’, says Wenzler.
‘In
our study, we also saw this: evening people smoke and drink more often
and exercise less. 25% of the risk of cognitive decline can be explained
from our research by smoking and poor sleep.’
Interestingly, the difference was found mostly in higher-educated people.
‘That
probably has to do with their sleep rhythm. They are often people who
have to go back to work early in the morning and are therefore more
likely to sleep too short, giving their brains too little rest.’
Genetic evolution
Wenzler, herself more of an early bird a night owl, explains how people’s biological clocks are genetically altered.
‘Children are morning people. That changes when you reach puberty,
when you become an evening person. Around your 20s, that gradually
shifts back towards morning people for most people.
‘By the age of
40, most people are morning people again. But this is certainly not the
case for everyone. In this way, evening people deviate from the norm’.
Work against your body as little as possible
There
is little you can do about being an evening person. That is why Wenzler
recommends working against your body as little as possible.
‘You
can try to go to sleep earlier, but if your body is not yet producing
melatonin (sleep hormone, ed.) it will not work: your body simply does
not want to sleep yet.
‘We suspect that lower- or middle-educated
people are more likely to have a job that allows them to take their
sleep rhythm into account, such as a job in the hospitality industry or
one with night shifts.
‘If this
is not possible, your brain does not get enough rest and you are more
likely to adopt bad habits. It would be nice if more consideration was
given to evening people who now have to work early: for example, by
giving them the option of starting later.’
Follow-up research
Meanwhile, Wenzler’s research continues.
‘We
are now investigating whether evening people are more likely to develop
dementia. Faster cognitive decline in middle age does not necessarily
mean a higher risk of dementia. With our research, we hope to find out
more about this. This will ultimately help us to be able to give people
informed advice on how to try to prevent dementia.’
About this chonotype and cognition research news
Author: Joost Wessels
Source: UMCG
Contact: Joost Wessels- UMCG
Image: The image is credited to Neuroscience News
Original Research: Open access.
“Chronotype
as a potential risk factor for cognitive decline: The mediating role of
sleep quality and health behaviours in a 10-year follow-up study” by Ana Wenzler et al. The Journal of Prevention of Alzheimer’s Disease
