Night owls have superior brain function, study finds

People who are night owls could be sharper than morning people, a new study suggests. Those who are most active and alert in the evenings appear to perform better at cognitive tests.

Researchers, led by academics from Imperial College London, said that various studies have examined sleep and cognitive abilities- in particular the length that someone sleeps – but little is known about sleep patterns, or chronotypes, and cognition.

So they examined data on thousands of people taking part in the UK Biobank study to examine the “intricate relationships” between sleep duration, quality and chronotype – categorised in the study as “morningness,” “eveningness” or “intermediate” – where a person did not particularly align to either of the two.

People taking part in the study underwent tests which examined their intelligence, reasoning skills, reaction times and memory.

The researchers analysed data on almost 27,000 people, comparing how well they performed on these tests to their self-reported sleep duration, sleep pattern and sleep quality.

People who got between seven and nine hours of sleep each night appeared to perform best on the tests, according to the study, which has been published in the journal BMJ Public Health.

Academics also found that night owls and those classed as “intermediate” had “superior cognitive function”.

Being a woman, increasing age and having a diagnosis of angina, high blood pressure and diabetes appeared to “worsen cognitive performance”, they added.

“Our study found that adults who are naturally more active in the evening – what we called ‘eveningness’ – tended to perform better on cognitive tests than those who are ‘morning people’,” said lead author of the study, Dr Raha West, from the Department of Surgery and Cancer at Imperial College London.

“Rather than just being personal preferences, these chronotypes could impact our cognitive function.

She added: “While understanding and working with your natural sleep tendencies is essential, it’s equally important to remember to get just enough sleep, not too long or too short. This is crucial for keeping your brain healthy and functioning at its best.”

Co-study leader Professor Daqing Ma, also from Imperial’s Department of Surgery and Cancer, added: “We found that sleep duration has a direct effect on brain function, and we believe that proactively managing sleep patterns is really important for boosting, and safeguarding, the way our brains work.

“We’d ideally like to see policy interventions to help sleep patterns improve in the general population.”