Scientists discover optimal amount of sleep for daily sleep after quarantine

We spend an average of 3,000 hours a year in dreamland, or a third of our lives between duvet cover and pillow. And rightly so, sleep is linked to a whole host of cognitive and physiological processes in the body, and too little of it can have detrimental effects on health.

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As we age, our sleep patterns can also change, and it becomes important to know how much sleep is optimal for healthy functioning. In a study published in the journal Nature Aging, scientists from Cambridge University in England and Fudan in China may have found an answer. Looking at data from the UK BioBank, the researchers studied 498,277 participants aged 38 to 73 who completed surveys about their sleep habits and duration, mental health and general well-being. Of this group, 40,000 participants had brain imaging profiles and additional genetic data available for analysis.

The results of the study suggest that participants who sleep about 7 hours a day without major disruption to their daily sleep patterns for extended periods had better cognitive performance, better mental health and better long-term general well-being. Sleeping less or more seems to be associated with reduced memory, but also with logical abilities. Scientists involved in the study also found a link in some participants between the amount of sleep and changes in the volume of key areas of the brain that work in memory, such as the hippocampus and other areas responsible for cognitive processing.

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“While we cannot say for sure that too much or too little sleep causes cognitive problems, our analysis of individuals over a longer period of time seems to support this idea. But the reasons why older people sleep less appear to be complex, influenced by a combination of our genetic makeup and brain structure,” Fudan University professor Jianfeng Feng said in a statement.

The authors offer a possible explanation as to why insufficient sleep as you age can lead to cognitive decline. They say it could be due to a disruption in slow-wave sleep, which has been linked to dementia and memory problems in previous studies. While the current study doesn’t specify why too much sleep might be bad, previous research has shown that too much sleep can also lead to cognitive decline.

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Sleep 7 hours a night to stay healthy

That said, due to the large sample size (498,277 analyzed cases) used for the study, the results can therefore be considered robust. However, the authors point out some limitations. The surveys were self-reported, which may introduce some bias, and the study only asked about participants’ total sleep time and did not examine other aspects such as bed hygiene practices. So this is a first step, but future studies could certainly deepen these results. So far, we can say that as we get older, getting seven hours of sleep a night seems to be the best way to maintain good health.

“A good night’s sleep is essential at all stages of life, but especially as you get older. Finding ways to improve the sleep of the elderly can be crucial in helping them maintain good mental health and general well-being and prevent deterioration, especially for patients suffering from psychiatric disorders and dementia,” said the professor. Barbara Sahakian, of the Department of Psychiatry at the University of Cambridge.

Interesting, isn’t it?

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