Researchers said participants who enjoyed regular afternoon kips showed better verbal fluency, locational awareness, and working memory.
Of those who took part in the researchers – published in online journal General Psychiatry – 1,534 took frequent afternoon naps of between five minutes and two hours, while 680 did not.
All participants took part in a dementia screening test, which found “significant” differences in locational awareness, verbal fluency and memory, with scores higher among the napping group.
The study’s authors said: “In addition to reducing sleepiness, mid-day naps offer a variety of benefits such as memory consolidation, preparation for subsequent learning, executive functioning enhancement and a boost to emotional stability, but these effects were not observed in all cases.”
Participants were asked how often they napped during the week, with answers ranging from once a week to every day.
The average length of nighttime sleep was around 6.5 hours in both groups but there was no information taken on the specific duration or timing of the naps taken.
Researchers said there were some possible explanations for the findings, with one theory suggesting that sleep regulates the body’s immune response and napping is thought to be an evolved response to inflammation.
“Individuals with higher levels of inflammation also nap more frequently,” the study said.
However, the study’s authors also acknowledged that current research has not yet been able to establish whether afternoon naps can help stave off dementia and cognitive decline in older people.
Dr Sara Imarisio, head of research at Alzheimer’s Research UK, said: “Scientists continue to work to unravel the relationship between sleep and dementia. Unusual sleep patterns are common for people with dementia, but research suggests that sleep changes could be apparent long before any symptoms like memory loss start to show.
“In this study, scientists were unable to find out whether daytime napping directly affected memory and thinking, with the research merely showing a link between the two.
“While other studies have also indicated a link between changes in sleep quality, a larger study looking at a number of sleep-related factors, not just napping, is needed to paint a clearer picture about the link between dementia and sleep throughout the day.”
Increase in life expectancy – and the associated neurodegenerative changes that come with old age – has resulted in an increase in dementia diagnoses over recent years.
Approximately five to seven per cent of people over the age of 65 in the developed world have been affected by the condition.