The risk of senile dementia and some other age-related brain disorders depends on the duration of our sleep. That is why it is necessary to spend at least 7-8 hours on a night’s rest.

Scientists from Washington University in St. Louis have proven in the course of the study that there is a so-called average range or golden mean of the duration of nightly sleep.

If it is observed, the cognitive abilities of the brain remain stable over a long period of time. The authors of the study observed the sleep of 100 elderly people who had previously been tested for various types of cognitive disorders and symptoms of Alzheimer’s disease. It turned out that those who spent 6 to 8 hours on sleep best preserved brain functionality.

If a person slept less than five and a half hours, then his cognitive abilities deteriorated even taking into account such factors as age, gender and senile dementia. This also applied to those people who slept too much.

Excess sleep also led to cognitive deterioration. The golden sleep duration is called 7.5 hours. It is advisable to sleep not much more, but not much less.

Another study suggests that the quality of sleep is of key importance in preserving intellectual abilities and memory. If we get enough sleep regularly, that is, we rest adequately, the body is completely cleansed of various kinds of dangerous toxic particles in the brain, the accumulation of which can lead to serious problems in old age.