The way you sleep can promote, or on the contrary, reduce the risk of developing Alzheimer’s disease. This is the finding of a new study led by Associate Professor Matthew Pase, from the Monash School of Psychological Sciences and the Turner Institute for Brain and Mental Health in Melbourne (Australia) and published on October 30, 2023 in JAMA Neurology.
Only a 1% reduction in deep sleep per year in people over 60 years old results in a 27% increase in the risk of dementia. For clarification: Alzheimer’s disease corresponds to the best known form of dementia. The study thus suggests improving or maintaining deep sleep to prevent dementia.
Sleep helps eliminate metabolic waste from the brain
The study focused on 346 participants, aged over 60enrolled in the Framingham Heart Study which conducted two nocturnal sleep studies during the periods 1995 to 1998 and 2001 to 2003, with an average of five years between the two studies.
The participants were carefully monitored for dementia. The researchers found, on average, that the amount of deep sleep decreased between the two studies, therefore with aging. During the 17 years of monitoring, 52 cases of dementia were recorded.
Even when controlling for age, sex, cohort, genetic factors, smoking, use of sleeping pills, antidepressants, and anxiolytics, each percentage decline in deep sleep each year was associated with a 27% increase in the risk of dementia.
“Slow-wave sleep, or deep sleep, supports brain aging in several ways, and we know that sleep increases the removal of metabolic waste from the brain, including facilitating the removal of proteins that aggregate in Alzheimer’s disease.“, said Professor Pase.
In other words, reducing your deep sleep time, you prevent the elimination of metabolic waste of the brain and allow Alzheimer’s disease to take hold.
“Our results suggest that loss of deep sleep may be a modifiable risk factor for dementia“, maintains the Professor.
“We examined how deep sleep changed with aging and whether changes were associated with dementia risk later in life up to 17 years later“, he added. In view of the study, it seems that the answer is yes.
