Chinese scientists have found that people who sleep after dinner, show better results in tests of orientation, fluency and working memory.
Researchers from the Shanghai Mental Health Center and Shanghai Jiaotong University decided to reveal whether afternoon sleep in the elderly is a protective body response to help prevent cognitive decline, or one of the symptoms of dementia.
The MMSE dementia test found that cognitive scores were significantly higher in those who regularly slept during the day.
As the scientists note, their study is observational, meaning that it proves that two factors – in this case, daytime sleep and brain health – are related, but it does not reveal the cause of this relationship.
The study’s authors believe that sleep regulates the body’s immune response, an evolutionary response to inflammation. In addition, people with high levels of inflammation sleep more frequently, and inflammatory chemicals play an important role in sleep disturbances. That said, daytime sleep helps prevent this inflammation.
At the same time, however, researchers believe that afternoon sleep is often associated with sedentary lifestyles and impaired circulation of leptin and ghrelin, peptide hormones that regulate energy metabolism.
Earlier, Alexander Kalinkin, head of the Center for Sleep Medicine at Lomonosov Moscow State University and candidate of medical sciences, warned that lack of sleep has a detrimental effect on the immune system. According to him, if a person sleeps less than five hours, his chances of catching a viral infection increases by 250 percent compared with people who sleep the necessary seven to nine hours.