Regular daytime sleep is good for the brain of older people

Chi­nese sci­en­tists from Shang­hai claim that day­time sleep in old age improves brain func­tion and mem­o­ry, and is also asso­ci­at­ed with increased flu­en­cy and con­fi­dent ori­en­ta­tion in space.

More than 2,000 peo­ple aged 60 and over par­tic­i­pat­ed in the sci­en­tif­ic project. Of this num­ber, approx­i­mate­ly 1,500 peo­ple had more or less reg­u­lar after­noon naps, and 680 peo­ple did not. On aver­age, at night, sub­jects from both groups slept for 6–7 hours. After­noon nap was defined as a peri­od of sleep last­ing at least 5 min­utes in a row, but not more than 2 hours. The fre­quen­cy of day­time sleep var­ied among the respon­dents from 1 time per week to dai­ly.

The researchers com­pared the scores on cog­ni­tive func­tion tests for par­tic­i­pants from both groups. It turned out that sig­nif­i­cant­ly high­er results were shown by peo­ple who slept dur­ing the day. Par­tic­i­pants who had an after­noon nap demon­strat­ed more con­fi­dent spa­tial coor­di­na­tion, high­er ver­bal flu­en­cy, and bet­ter mem­o­ry.

Sci­en­tists believe that we need sleep to reg­u­late the immune response. Per­haps day­time sleep is an evo­lu­tion­ary response to inflam­ma­tion. This is con­firmed by the fact that sick peo­ple with a high lev­el of inflam­ma­to­ry process­es also sleep more.