According to a new study conducted by academics at UCL and the University of the Republic in Uruguay, daytime napping may assist to protect brain function by slowing the speed at which our brains shrink as we age.The study, published in the journal Sleep Health, analysed data from people aged 40 to 69 and found a causal link between habitual napping and larger total brain volume - a marker of good brain health linked to a lower risk of dementia and other diseases.Senior author Dr Victoria Garfield (MRC Unit for Lifelong Health & Ageing at UCL) said: "Our findings suggest that, for some people, short daytime naps may be a part of the puzzle that could help preserve the health of the brain as we get older."Previous research has shown that napping has cognitive benefits, with people who have had a short nap performing better in cognitive tests in the hours afterwards than counterparts who did not nap.The new study aimed to establish if there was a causal relationship betwe