This many hours of sleep is optimal from middle age
How much sleep is enough – and how much is too much? The need for sleep varies from person to person, and age also plays a role. Researchers are now making a recommendation for people of middle age and older.
SSeven hours of night’s sleep is the ideal length of sleep for middle-aged and old people. The report US and Chinese scientists in the journal “Nature Aging”. The conclusion of the study is that significantly more or less sleep is associated with impairment of mental health and poorer mental performance. Good sleep is all the more important for older people.
Specifically, scientists from the Universities of Cambridge and Fuhan examined data from nearly 500,000 adults between the ages of 38 and 73 collected in the UK Biobank, a comprehensive British database. The subjects were asked about their sleep patterns, mental health and well-being, and also took part in a series of cognitive tests. MRI images of the brain and genetic data were available for almost 40,000 participants.
The analysis of all this information showed that both too little and too much sleep was associated with reduced cognitive performance – the corresponding subjects were slower on the tests and had a shorter attention span and poorer problem-solving skills. Their mental health also suffered: people who got too much or too little sleep showed more symptoms of anxiety and depression depression and overall lower general well-being.
The researchers suspect that a disruption in slow-wave sleep, part of deep sleep, could be a possible reason for the cognitive decline. Such a disorder is associated with an accumulation of beta-amyloid molecules. These protein deposits, which are found in large clumps in the brains of Alzheimer’s patients, are suspected of contributing to the death of nerve cells.
The analysis of the brain scans also revealed a connection between different sleep durations and differences in the structure of brain regions involved in cognitive processing and memory. Among them was the hippocampus, which is considered the memory center of the brain.
Overall, the researchers conclude, seven hours of uninterrupted sleep appears to be most ideal for cognitive performance, general well-being, and mental health in middle-aged and older people. Although the study did not describe causality, the results indicated that insufficient or excessive sleep duration could be a risk factor for cognitive decline in old age.
As author Jianfeng Feng emphasizes in a statement: “While we cannot definitively say that too little or too much sleep causes cognitive problems, our analysis, which looks at people over a longer period of time, seems to support this idea.”
However, the reasons older people slept poorly seemed complex, involving a combination of genetics and brain structure.
Neuropsychologist and co-author Barbara Sahakian adds that good sleep is important at all stages of life, but especially as we age: “Finding ways to improve the sleep of older people could be crucial in helping them improve their mental health and well-being and avoid cognitive decline, particularly in patients with psychiatric disorders and dementia.”
In fact, according to the German Society for Sleep Research and Sleep Medicine (DGSM), older people in particular often report problems staying asleep, a decreasing total sleep time, more naps during the day and an increasing use of sleeping pills. Increasingly, however, sleep difficulties are being identified across age groups and worldwide.
In Germany alone, a third of those surveyed in a 2017 study by the Techniker-Krankenkasse complained about sleep problems, and every second person said they got no more than six hours of sleep. It should be noisy for seven to nine hours a policy the US National Sleep Foundation (NSF) for adults. However, their authors emphasize that the need for sleep differs from person to person.
This article was first published in May 2022.
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