A BBC news report examines some current data and research that can help explain whether or not more or less sleep is needed as people age.
Support for a role for the impact of circadian rhythms on the disruption of sleep in older people, comes from brand new data obtained using a smartphone app called Entrain, developed by the researchers at the University of Michigan, Ann Arbor, to help people adjust their light levels at different times of day in the hope of combatting jet lag.
Users of the app are asked about their typical sleep patterns and can choose whether to share that data the researchers. Five thousand people from around the world did, which has provided a snapshot of global sleeping habits of people of different ages. Among the young people there was a range of early risers and night owls, but the older group was more homogenous.
Most woke early and went to bed relatively early. In this study it was the men in their 40s who seemed to get the least sleep, which is unusual. But the finding that older people sleep at more specific times suggests that there is a narrower range of times in which people past retirement age are able to get to sleep and stay asleep.
So changes in the body clock stop older people getting to sleep and keep older people awake, maybe, then, it is a myth that they need less sleep. It’s simply that they have a narrower window in which to sleep. Perhaps the daytime napping isn’t preventing sleep at night. Instead the lack of sleep in the night is causing sleepiness in the daytime, hence the need for a nap to make up for the lost sleep.