Appropriate quiet sleep is extremely important to feel good and rest.
During sleep, for example, growth hormones are released, which among other things are responsible for the regeneration of the muscles.
In addition, hormones are released into sleep, which increase body temperature and promote deep sleep and transmit important substances to messengers to the immune system.
However, those who often break night sleep will increase the risk of illness. But not only duration but also quality of sleep is important for optimal functioning of the body.
According to a recent study at the University of Washington Medical School at St. Louise, poor quality of sleep is associated with increased risk of Alzheimer's disease.
It remains unclear, however, whether bad sleep is just an indication or responsible for dementia.
Bad dream as an indicator of Alzheimer's disease?
Scientists wanted to use their research to determine whether the duration and quality of sleep affecting the production of so-called proteins. It is suspected that this protein is the major cause of dementia.
For this reason, the research team examined the behavior of sleep by a total of 119 subjects older than 60 who had no cognitive impairment.
Subjects were carrying the EEG (electroencephalography) device over their foreheads for one week to measure brain waves during sleep. In addition, a special bracelet on the wrist recorded movements of the body of the respondent.
In addition, the participants conducted a diary in which they wrote their sleeping time – both the night and the afternoon dreams – in writing.
After a week, scientists used a so-called PET test to check the amount of protein in the brain and spinal cord of the examinee.
Sleep quality is more important than life expectancy
The results of the study were clear: subjects with a lower sleep period showed increased concentration of tau protein. The deep sleep changes the so-called REM phase of sleep, pulse, breathing and blood pressure and brain activity.
"Interestingly, on the one hand, people with less deep sleep had more protein in the brain, but on the other hand, they did not have mental limitations," said Brendan Lucey of the Sleeping Center and Research Manager.
"Reduced deep sleep can be a sign of a transition between normal and damaged," says Brendan.
Research results have also shown that quality – but not sleep duration – affects the amount of protein in the brain and is therefore associated with Alzheimer's disease.
However, researchers are still not sure whether bad sleep is just an indication of initial dementia or even a cause of the disease.