Scientists have found the optimal amount of night sleep for the elderly

Do you get enough sleep at night? If not, it can affect your mental health and overall well-being. A major new study of 500,000 adults has identified the risks of not getting enough sleep or, conversely, getting too much. This review is the result of work done by scientists from Cambridge University (UK) and Fudan University (China).

How long should you sleep?

Experts found that seven hours of sleep at night is the optimal amount for middle-aged and older people. It helps maintain both a person's mental health and uninterrupted brain function, including memory and problem-solving skills. Study participants showed more symptoms of anxiety and depression and, in general, worse well-being if they slept more or less than this amount of time. One possible reason for the relationship between sleep deprivation and cognitive decline may be impaired deep sleep phases, the researchers say. Lack of sleep may also impair the brain's ability to get rid of toxins.

Is poor sleep related to Alzheimer's disease and dementia?

According to scientists, their findings suggest that not getting enough or too much sleep may be a risk factor for developing cognitive decline with age. This is also supported by previous studies that have found a correlation between sleep duration and the risk of developing Alzheimer's disease and dementia, in which diminished mental capacity is a determining factor.

Professor Barbara Sahakian of the Department of Psychiatry at Cambridge University says: "A good night's sleep is important at all stages of life, but especially when we reach old age. Finding ways to improve sleep in older adults can be critical in helping them maintain good mental health and well-being and avoid a decline in their mental faculties. This is especially true for patients with psychiatric disorders and dementia."

Professor Jianfeng Feng of Fudan University notes: "Since we cannot conclusively say that too little or too much sleep causes cognitive problems, our analysis with recipients over a long period of time seems to support this idea. The reasons why older people sleep worse are complex and depend on a combination of genes and brain structure."

Who was involved in the study?

The work of British and Chinese scientists involved 500,000 people whose ages ranged from 38 to 73. The recipients were asked about their sleep quality, mental health and well-being. They also underwent a series of intelligence tests. Brain scans and genetic data from approximately 40,000 participants were also available for the study. The results were published in the journal Nature Aging.