According to a study conducted in 2023, people over 60 are 27% more likely to develop dementia if they lose just 1% of a certain stage of sleep each year, writes Science Alert.
Slow-wave sleep (or NREM) is the third stage of a 90-minute human sleep cycle, lasting about 20-40 minutes. It is the most restful stage, where brain waves and heart rate slow and blood pressure drops.
Deep sleep strengthens our muscles, bones and immune system and prepares our brain to absorb more information. Recently, research found that people with Alzheimer’s-related brain changes did better on memory tests when they got more slow-wave sleep.
“Slow-wave sleep, or deep sleep, supports brain aging”
“Slow-wave sleep, or deep sleep, supports brain aging in many ways, and we know that sleep enhances the removal of metabolic waste from the brain, including facilitating the removal of proteins that aggregate in Alzheimer’s disease,” said Matthew Pase, a neuroscientist at Monash University in Australia. .
Pase and colleagues from Australia, Canada and the US studied 346 participants in the Framingham Heart Study, who completed two nocturnal sleep studies between 1995 and 1998 and between 2001 and 2003, with an average of five years between testing sessions.
This community cohort, which was free of dementia at the time of the study from 2001-2003 and was over 60 years old in 2020, gave the researchers the opportunity to look at the link between sleep and dementia over time by comparing data from the two studies polysomnographic sleep and follow-up of dementia cases until 2018.
“We used these data to examine how slow-wave sleep changes with age and whether changes in the percentage of slow-wave sleep are associated with dementia risk at older ages, up to 17 years later,” a Pase explained.
Alzheimer’s, the most common form of dementia
During the 17 years of follow-up, 52 cases of dementia were recorded among the participants. Levels of slow-wave sleep recorded in sleep studies were analyzed to establish a link with these cases. In general, participants’ slow-wave sleep rate was found to decline from age 60, reaching a low between 75 and 80 and leveling off thereafter.
Comparing data from the participants’ first and second sleep studies, the researchers found that each percent decrease in slow-wave sleep per year was associated with a 27 percent increased risk of developing dementia. That risk rose to 32 percent when the analysis focused on Alzheimer’s disease, the most common form of dementia.
Source: www.descopera.ro
