We spend an average of 3,000 hours a year in dreamland, or a third of our lives between a duvet cover and a pillow. And for good reason, sleep is linked to a whole gamut of cognitive and physiological processes in the body, and not getting enough of it can have adverse health consequences.
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 Nature Aging, scientists from Cambridge University in England and Fudan in China may have found an answer. Looking at data from BioBank in the UK, researchers studied 498,277 participants between the ages of 38 and 73 who completed surveys about their sleep habits and duration, and mental health and general well-being. Of this group, 40,000 participants had brain imaging files and additional genetic data available for analysis.
Les résultats de l’étude suggèrent que les participants qui dorment environ 7 heures par jour sans perturbation majeure de leur rythme de sommeil quotidien pendant des périodes prolongées ont de meilleures performances’ cognitives’, une meilleure mental santuré équen long term Sleeping too little or more appears to be associated with poor memory, but also with logical abilities. Scientists involved in the study also found in some of the participants a link between the amount of sleep and changes in the volume of key brain regions working in memory, such as the hippocampus and other areas responsible for cognitive processing.
Credit: Quinn Stevenson
“Although we cannot definitively say that too much or too little sleep causes cognitive problems, our analysis of individuals over a longer period of time appears to support this notion. The reasons why older adults are more likely to be affected by this is the case,” Professor Jianfengfeng of Fudan University said in a statement. Sleeping less appears complex, influenced by a combination of genetic makeup and brain structure.
The authors offer a possible explanation for why insufficient sleep as you age can lead to cognitive decline. They say it may be due to slow-wave sleep disorder, which has been linked to dementia and memory difficulties in previous studies. While the current study does not determine why too much sleep is a bad thing, previous research has shown that too much sleep can also lead to cognitive decline.
Credit: Andishe A
Sleep 7 hours a night to stay healthy
However, given the large sample size (498,277 cases analyzed) used in the study, the results can therefore be considered robust. However, the authors point out some limitations. The surveys were self-reported, which may lead to some bias, and the study only asked about the participants’ total sleep time and did not examine other aspects such as bed hygiene and sleep practices. So this is the first step, but future studies can certainly deepen these findings. So far, we can say that as we get older, getting seven hours of sleep each night seems to be the best way to maintain good health.
“Getting a good night’s sleep is essential throughout life, but especially as you age. Finding ways to improve the sleep of older adults can be critical to helping them maintain good mental health, general well-being and avoid deterioration, especially for patients with of mental disorders and dementia,” said Professor Barbara Sahakian, from the Department of Psychiatry at the University of Cambridge.
Fun, isn’t it?