A study published in the Journal of the American Geriatrics Society found that taking an hour-long nap after lunch can keep the brain five years younger.
The researchers however found that taking a longer or shorter nap after lunch will have no effect at all.
The researchers came to this conclusion after observing 3000 Chinese adults over the age of 65 with 60 per cent reporting that they had a nap after lunch ranging from 30 to 90 minutes.
Dr Junxin Li, who led the research said: “Cognitive function was significantly associated with napping. Comparisons showed that moderate nappers had better overall cognition than non-nappers or extended nappers.
“Non-nappers also had significantly poorer cognition than short nappers.”