Alzheimer’s: the nap would improve cognitive functions

Sleep is an important element for the proper functioning of our cognitive functions. So much so that the sleep apnea syndrome, which fragments the latter, can disturb the memory of patients who suffer from it and suggest that they have dementia, when this is not the case.

Link between siesta, cognitive function and the elderly

The Chinese researchers therefore wanted to explore the link between cognitive function and naps during the afternoon in aging subjects. They included in their work 2214 elderly subjects, some of whom took a nap (1534 participants in total) and others who did not (the other 680 volunteers).

The researchers defined the afternoon nap as “periods of inactivity of at least five consecutive minutes marked as sleep (inactivity) after lunch outside of the main sleep schedule”. The elderly were asked about their habits through a questionnaire, whether they took a nap (yes or no) and if so how often: once a week, one to three times, four to six times or seven times ( everyday).

All participants were subjected to various neuropsychological tests and cognitive assessments, as well as an examination of their mental state. On a voluntary basis, 739 of the 2,214 elderly people in this study also gave their consent to undergo blood tests to assess their blood lipid levels.

Significant differences

The study showed several things. On the one hand, the scientists found significant differences between the two groups. The afternoon nap was associated with a “better cognitive function, including orientation, language, and memory” according to the researchers. In contrast, subjects with a habit of taking afternoon naps also showed higher triglyceride levels than subjects who did not take naps.

For Dr. Liath Guetta, “The link between sleep and cognitive disorders is well known. If the night’s sleep is too fragmented, patients are advised not to go to bed too early at night and to take a 20-minute nap after lunch. explains the sleep specialist. For her, it is important to keep quality sleep at night, the most restorative.

A scientific study with biases

The scientists also point out the limitations of their work, explaining that it is a correlation and not a causal link: “they could not show direct causation of the nap, whether beneficial or harmful”. In addition, the study being based on a questionnaire, the result therefore depends on the data provided by the participants, which presents a possible bias.

However, these initial results encourage the authors to continue their work. Indeed, they are already announcing that they want “carry out further work on this cohort in the future“.