It is commonly accepted that elderly people need less sleep than the young, but this is not necessarily the case. It is true that they often get less rest, but this is due to the deterioration of the brain that is associated with age, as opposed to not actually needing the sleep.
A new scientific review is challenging the pre-existing wisdom on how much sleep is needed as we age. It has found that many older people appear to function on little rest, because they have adjusted to a life where they get minimal sleep each night.
Older people didn’t appear as exhausted after missing out on sleep as their younger counterparts and still managed to carry out everyday tasks. It is thought that they have a similar drive to sleep, but their brains are less susceptible to it.
While it could be considered that the situation is fine, because they can still function, this state of affairs could be taking a toll on the health of the elderly. Not sleeping enough can lead to dementia and a plethora of other illnesses.
Study author Professor Matthew Walker, of the University of California, Berkeley, explained why older people might be getting less rest. He said that as the brain ages, the neurons and circuits in the sections that regulate sleep start to degrade.
This leads to less non-REM sleep, which is important for maintaining memory and cognition. It is therefore not the fact that the elderly have stopped having such busy lives or that they don’t need the sleep, but a deterioration of the brain that stops them from getting it.
Professor Walker wrote in the journal, Neuron: “Sleep changes with ageing, but it doesn't just change with ageing, it can also start to explain ageing itself. There is a debate in the literature as to whether older adults need less sleep, or rather, older adults cannot generate the sleep that they nevertheless need.
“The evidence seems to favour one side - older adults do not have a reduced sleep need, but instead, an impaired ability to generate sleep. The elderly therefore suffer from an unmet sleep need.”
It is unclear how widespread the problem is, as many older people are thought not to report issues with sleeping, because they have become accustomed to being sleep deprived. Chemical markers showed up in tests, however, indicating disrupted brain waves while asleep.
Surprisingly, sleep quality starts to decline as early as the mid-thirties, but happens slowly, so is not necessarily noticed by the individual. Over time, people shift towards an early-to-bed-early-to-rise routine or even start waking up multiple times in the night.
Deterioration in non-REM sleep is worse for men than women, although changes to REM sleep are similar in both genders. Anyone whose sleep degradation is of a higher-than-normal level is likely to be at a greater risk of conditions, such as dementia and Alzheimer’s disease.
At present, there are no clear treatments to help those whose sleep is deteriorating, meaning lifestyle choices are key. These include keeping a good routine, avoiding caffeine in the afternoon and only drinking alcohol moderately.