“Night Owls” Appear to Have Better Brain Function
A new study out of Imperial College London found a surprising association: for older adults, being a “night owl” appears to be tied to better cognitive ability compared to being a “morning lark.”
“Previous studies have shown that disruptions in circadian rhythms, like those caused by shift work or jet lag, can negatively impact cognitive abilities,” says Dr. Raha West, a National Institute for Health and Care Research doctoral research fellow in the Department of Surgery & Cancer at Imperial College London. “However, how being a morning or evening person affects cognitive function is less known, especially in older adults, which is why we did the study.”
The Research on Night Owls vs. Morning Larks
The researchers looked at U.K. Biobank data from more than 26,000 people who were between the ages of 53 and 86. The participants had completed a series of cognitive tests that measured things like reaction time, memory, and fluid intelligence, in addition to self-identifying as “night owls,” “morning larks,” or somewhere in the middle.
The terms “night owl” and “morning lark” refer to chronotypes, that is, what time of day a person is most active based on their sleeping patterns.
Here are some of the findings:
• Sleeping between 7 and 9 hours a night was optimal for brain function and boosting cognitive ability. Getting less than 7 hours of sleep or more than 9 hours negatively impacted cognitive test scores.
• “Night owls” had improved cognitive test scored compared to “morning larks.”
• Younger-aged participants and participants with no chronic diseases generally scored higher in cognitive tests.
“We were intrigued by these findings because previous research on younger people has indicated that morning types tend to have better health and cognitive outcomes,” says West. “However, our study suggests that the relationship between chronotype and cognitive performance may change with age. These findings show that evening types were associated with better cognitive function in our older cohort, possibly due to changes in circadian rhythms and their influencer on brain function as people age.”
More Research is Needed
Additional research is needed to understand why older “night owls” seem to perform better cognitively and West is curious if expanding the cohorts would produce similar results.
“Investigating whether these findings apply to other age groups and different populations would also be interesting,” she says. “Additionally, examining the role of sleep quality in greater detail and considering other factors like physical activity, diet, and social engagement would be good.”
To be clear, the study found associations, not causality, so “morning larks” shouldn’t attempt to change their sleep schedules or worry about harming their cognitive health. The most important take-away is to focus on getting 7 to 9 hours of good quality sleep.
As West points out, “There is a wide range of cognitive performance within each chronotype. Maintaining a consistent sleep schedule and ensuring you get the right amount of sleep is crucial for cognitive health, regardless of whether you are a morning or evening person.”
The study was published in the July 10, 2024 issue of the journal BMJ Public Health.
MBJ
Wendy Burt-Thomas writes about the brain, mental health and parenting.
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