We have often heard that an adult needs between seven and nine hours sleep a night to feel properly refreshed and to function at their best the next day.
A new international study led by researchers at Monash University has found that it’s the quality of sleep rather than quantity and how well it is maintained throughout the night is associated with better cognitive function.
Published in JAMA Network Open, the study investigated 5946 adults in the USA in five independent community-based cohorts involving an overnight sleep study and neuropsychological assessments.
“Our findings suggest different elements of sleep are important for cognitive health, particularly the quality of someone’s overnight sleep and whether or not they have sleep apnoea,” said Associate Professor Matthew Pase from the Turner Institute for Brain and Mental Health at Monash University.
Researchers found that better sleep quality and the absence of sleep apnoea in adults aged 58-89 who had not experienced stroke or dementia were associated with better cognition over five years of follow-up.
According to Associate Professor Pase the most interesting finding is “participants that have mild to severe sleep apnoea had worse cognition, so they had worse thinking and memory performance.”
“This is significant because there have been some studies that have shown relationships between obstructive sleep apnoea and poor cognition, but they’ve genuinely relied on people with a diagnosis,” he added.
According to Monash University, researchers will explore the aspects of sleep health most strongly related to dementia risk.