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Daytime naps can lead to dementia
Last reviewed: 01.07.2025
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Neurologists warn that daytime sleep is associated with dementia (acquired dementia, the breakdown of mental functions resulting from brain damage). Too frequent daytime sleep or long sleep at night (more than 9 hours) can lead to dementia and brain damage. Daytime sleep has the greatest impact on the body of mature women who lie down to rest after physical exertion. But French scientists who conducted research involving more than 5,000 years have sounded the alarm.
One in five people who regularly took afternoon naps had poor IQ test scores, the study found. Excessive daytime sleepiness may be an early predictor of cognitive decline. Another study found that people who slept more than nine hours a night but less than five had a decline in mental ability, suggesting that these findings suggest early stages of Alzheimer's disease, the most common form of dementia.
There is also some evidence linking sleep duration and disturbances leading to cardiovascular disease and diabetes, so it is not surprising that in addition, prolonged and daytime sleep affects people's cognitive abilities. In this regard, it has been recommended to sleep about seven hours a day.
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