‘Night owls’ appear to have better brain function, new study finds

But there is a wide range of cognitive performance within each chronotype

ANALYSIS | AGENCIES | A person’s chronotype defines what time of the day a person is most active based on their sleeping patterns.

For example, are you the type of person who wakes up early and is most active during the morning? Then your chronotype is popularly referred to as a “morning lark.” If you get the most done at night and then sleep in late, you are considered a “night owl.”

Past studies have compared these two chronotypes to see how they compare in different areas of health, including physical activity levels and mental, metabolic, and cognitive health.

“Understanding the impact of sleep on brain function is essential because sleep is crucial for various aspects of our health,” Raha West,MBChB, MRCA, National Institute for Health and Care Research Doctoral Research Fellow in the Department of Surgery & Cancer at Imperial College London explained to Medical News Today.

“It plays a key role in cognitive function, memory consolidation, emotional balance, and overall mental well-being. Poor sleep quality or insufficient sleep has been linked to numerous health issues, such as increased risk of neurodegenerative diseases, cognitive decline, and daily functioning impairments,” she added.

West is the lead author of a new study recently published in the journal BMJ Public Health that found that getting between 7 and 9 hours of sleep each night was optimal for brain health. The research team also found that people who identify as “night owls” may have better cognitive ability than “morning larks.”

For this study, West and her team analysed data from more than 26,000 adults ages 53 to 86 listed in the U.K. Biobank. Participants had completed various cognitive tests including memory, reaction time, and fluid intelligence.

The study’s first finding is that sleeping between 7 and 9 hours each night was optimal for brain function and boosting cognitive ability. Sleeping less than 7 hours and more than 9 hours negatively impacted cognitive test scores.

“Our finding of the association between sleep duration and cognitive function, with 7 to 9 hours of sleep being optimal, is significant because it aligns with existing evidence and highlights the importance of optimum sleep for maintaining cognitive health,” West said.

“This finding showed that not only too little but also too much sleep may be detrimental to brain performance. By identifying the best sleep duration, we can improve public health advice and encourage people to prioritize good sleep habits for better cognitive and overall health,” she advised.

‘Night owls’ score higher on cognitive tests

Next, scientists evaluated cognitive test differences between those who identified as “night owls” versus “morning larks.”

“Previous studies have shown that disruptions in circadian rhythms, like those caused by shift work or jet lag, can negatively impact cognitive abilities,” West explained. “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.”

When examining chronotypes, the researchers found that “night owls”, who were more active in the evenings, performed better on cognitive tests than “morning larks”, who were more active at the beginning of the day.

Scientists also found that participants in the middle who did not define themselves as a morning or evening person also had improved cognitive test scores when compared to “morning larks.”

Additionally, West and her team found that younger-aged participants and those without any chronic diseases generally scored higher in cognitive tests.

West said: “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. However, our study suggests that the relationship between chronotype and cognitive performance may change with age. The findings show that evening types were associated with better cognitive function in our older cohort, possibly due to changes in circadian rhythms and their influence on brain function as people age.”

“The next steps could include exploring why evening types might perform better cognitively in older adults,” she continued.

“Investigating whether these findings apply to other age groups and different populations would also be interesting. Additionally, examining the role of sleep quality in greater detail and considering other factors like physical activity, diet, and social engagement would be good,” the researcher further noted.

Should ‘larks’ aim to become ‘owls’?

Some may now worry if they are more morning-active than evening-active that they could be harming their cognitive health. Is that really the case though?

According to West, morning-active individuals should not worry about harming their cognitive health.

“Our study found associations, not causality, and there is a wide range of cognitive performance within each chronotype,” she emphasized.

“The key is to focus on getting high-quality sleep and understanding your natural sleep patterns. 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,” West advised.

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Source: MNT