A new study has uncovered a potential link between chronotype—whether you’re a night owl or early bird—and cognitive decline in individuals with higher education. Conducted by researchers from the University of Groningen in the Netherlands, the study analyzed the sleep habits and cognitive performance of nearly 24,000 individuals over a decade.
The study found that night owls who stayed up late and had university-level education faced a higher risk of cognitive decline. The research focused on individuals aged 40 and older, using data from a public health research database, and compared sleep patterns with cognitive scores on the Ruff Figural Fluency Test (RFFT), which measures cognitive ability.
According to the study, each one-hour increase in staying up late was linked to a 0.80-point decline in cognitive scores per decade among highly educated participants. The research also identified factors like sleep quality and smoking as partial contributors to this risk, though their impact was relatively small.
“Sleep quality and current smoking mediated 13.52 percent and 18.64 percent of the association, respectively,” the researchers noted. While smoking and poor sleep are already known to be associated with dementia, the study doesn’t prove a direct cause-and-effect relationship between being a night owl and faster cognitive decline. It simply reveals a noteworthy connection that warrants further investigation.
Interestingly, the study found no such association in individuals with lower or middle levels of education. It also found that factors like physical activity, past smoking, and alcohol consumption did not explain the link between chronotype and cognitive decline.
The researchers suggest that the more rigid work schedules of well-educated night owls could be a factor—requiring early mornings even after late nights, which might prevent the brain from getting adequate rest. They also propose that higher cognitive levels in these individuals could make declines more noticeable.
While past studies on this topic have yielded mixed results, this study adds valuable insight into the complex relationship between sleep and cognitive health. With aging populations and increasing dementia rates worldwide, understanding these factors has become a global priority.
“With rising life expectancies and aging populations worldwide, preserving cognitive health is an urgent global priority,” the researchers concluded.
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