S u m m a r y :
Less REM sleep is linked with a higher risk of developing dementia, says a new study published in the journal Neurology.
What is REM Sleep?
Rapid Eye Movement (REM) sleep is the sleep stage whereby one dozes off to dreamworld: the last of five phases of sleep, as established by a whole body of studies, it is marked by dreaming. It is preceded by light sleep (stage 1) which is followed by (stage 2) the body preparing itself for further stages which are characterised by deep sleep (stages 3 & 4).
REM has its own peculiarities. It entails:
- A rapid movement of the eyes (hence its name)
- Increased brain activity
- Higher body temperature
- Faster heartbeat rate
- Faster breathing rate
- It lasts for around 60 to 90 minutes after which it occurs in repetitive cycles throughout sleeping time.
Dreaming is a Protection!
Getting enough of dreaming is extremely important to humans, and now it appears that those enjoying less of it seem to be more susceptible to eventually suffering from dementia, says the new research.
While dementia has been linked with sleep problems in other studies, little evidence exists to show that the latter might be having a role in the risk of developing the condition, says study author Matthew P. Pase from Australia’s Swinburne University of Technology. This is what pushed Pase and his colleagues to determine which sleep phase might be associated with dementia.
Sleep & Alzheimer’s Disease
The participants of the study amounted to 321, with an average age of 67. Their sleep cycles were individually measured, and they were followed for around 12 years in a row. Throughout this period, 32 of them were diagnosed with dementia, 24 of whom were found to be suffering from Alzheimer’s disease.
The results show that the REM sleep of those with dementia accounted for an average of 17% of their total sleep time while those who did not develop dementia spent 20% of their sleep in REM. When the researchers looked closer at this trend, they found that a shorter time spent in REM was linked with a higher risk of dementia; every 1% reduction in REM sleep led to a 9% increase in the disease risk. Also, the longer it took to reach the REM phase, the greater the likelihood of developing the condition.
It is to be noted that the researchers found no link between a greater risk for dementia and other sleep stages.
Possible Treatment Techniques?
Pase concludes that REM sleep might be a predictor of dementia. Now, they look forward to finding out the cause behind this apparent association. The aim of further studies is to ultimately develop interventions for dementia patients.