Sleep plays an important role in stimulating cognitive functions and maintaining good mental health. It also helps maintain brain health by eliminating waste.
As we age, we often notice changes in our sleep patterns. Including difficulty falling asleep and staying asleep. As well as decreasing the quantity and quality of sleep.
These sleep disturbances are thought to contribute to cognitive decline and mental disorders in older adults.
Test nearly 500,000 adults
In a paper published today in Nature Aging, scientists from the United Kingdom and China looked at data from nearly 500,000 adults aged 38 to 73 years from the United Kingdom’s Biobank.
Participants were asked about their sleeping habits. As well as their mental health and well-being. They took part in a series of cognitive tests. Brain imaging and genetic data were available for nearly 40,000 study participants.
Sleeping too little or too much impairs cognitive performance
By analyzing this data, the team found that insufficient and excessive periods of sleep were associated with poorer cognitive performance. Such as processing speed, visual attention, memory, and problem-solving abilities.
Seven hours of sleep each night is the optimal amount of sleep for cognitive performance. But also for good mental health. For people with symptoms of anxiety and depression. But overall well-being worsened if they reported sleeping longer or shorter periods.
One possible reason for the link between insufficient sleep and cognitive decline may be slow-wave disruption — “deep” sleep, the researchers say.
Disruption of this type of sleep has been shown to be closely related to memory consolidation as well as amyloid accumulation. A key protein that can cause tangles in the brain when poorly folded. Characteristics of certain types of dementia.
Additionally, lack of sleep can hamper the brain’s ability to detoxify.
The team also found a link between the amount of sleep and differences in the structure of brain regions involved in cognitive processing and memory. Again with larger changes associated with sleeping more or less than seven hours.
Get consistent sleep
Getting seven hours of sleep each night consistently, without much fluctuation in duration, was also important for cognitive performance, good mental health, and well-being.
Previous studies have also shown that disrupted sleep patterns are associated with increased inflammation. Which indicates susceptibility to age-related diseases in the elderly.
Professor Jianfeng Feng from Fudan University in China said: “Although we cannot definitively say that too little or too much sleep causes cognitive problems. Our analysis of individuals over a longer period seems to support this idea.”
“But the reasons why older adults sleep seems complex, influenced by a combination of our genetic makeup and the structure of our brains.”
The risk of cognitive decline associated with aging
The researchers say the findings suggest that too little or too much sleep may be a risk factor for cognitive decline associated with aging.
This is supported by previous studies that have suggested a link between sleep duration and the risk of Alzheimer’s disease and dementia. Where cognitive decline is a characteristic symptom.
One of the study’s authors, Professor Barbara Sahakian from the Department of Psychiatry at the University of Cambridge, said: “Getting a good night’s sleep is important throughout life, but especially as we age.”
Finding ways to improve sleep in older adults can be crucial in helping them maintain good mental health. In addition, to avoid cognitive decline especially for patients with mental disorders and dementia. »