The Truth About Sleep and Your Risk of Dementia
Current research suggests a relationship between sleep quality and dementia risk through a seldom-mentioned body system.
An introduction to dementia and Alzheimer’s disease
According to the Centers for Disease Control and Prevention (CDC), dementia is “not a specific disease” but “a general term for the impaired ability to remember, think, or make decisions that interferes with doing everyday activities.”
While there are several factors that can increase your risk of developing dementia, the strongest risk factor is age. Most dementia cases affect adults of 65 years and older. Dementia that occurs prior to the age of 65 is referred to as “early onset dementia” and is typically associated with genetic risk factors.
“The most significant risk factor for developing protein aggregation — just as it is for developing dementia — is age” (Source: National Library of Medicine)
The most common cause of dementia is Alzheimer’s disease, which has been associated with the build-up of certain proteins in the brain. These proteins, beta amyloid and tau, can contribute to cognitive decline. The interesting thing about your body is that it can usually clear up protein build-up and tangles in your brain through the glymphatic system.
What is your glymphatic system’s function?
The glymphatic system essentially serves as a garbage-collection system for your brain. During the day, your brain accumulates waste, including certain proteins it doesn’t need. At night, in your deepest stage of sleep, your glymphatic system washes away this waste.
If these proteins aren’t washed away, they start to aggregate and tangle. This can destroy your brain cells and slow down the glymphatic system, creating a vicious cycle where a poorly functioning glymphatic systems leads to a buildup of misfolded proteins which further damages the functioning of the glymphatic system. As the glymphatic system slows down, it struggles to clean up proteins, which leads to more build-up and less cleaning. Natural degradation of the glymphatic system occurs with age, but when the degradation speeds up too quickly it leads to neurodegeneration (loss of brain matter) and dementia.
How sleep can reduce your risk of dementia
Dementia is associated with a build-up of proteins and tangles within the brain. Usually, your glymphatic system washes away proteins while you’re asleep. Lack of proper sleep slows your glymphatic system and makes it difficult for it to clean proteins in your brain. Over time, this leads to build up, an impaired glymphatic system, and dementia.
There’s research to support the role of poor sleep as being a risk factor for dementia. A 2021 study from Harvard Medical School found that individuals who slept less than 5 hours each night were twice as likely to develop dementia than individuals who slept 7 to 8 hours each night.
In another study, researchers found that individuals of ages 50, 60, and 70 who regularly slept for 6 hours or less each night had a 30 percent higher risk of developing dementia than individuals who regularly slept for 7 hours. A 2018 study found that just one night of poor sleep increased amyloid beta build-up in the brain. Amyloid beta build-up is characteristic of Alzheimer’s.
How do you improve the way your glymphatic system works?
If you are someone with an increased risk of dementia or Alzheimer’s, there are several decisions you can make about your sleep habits that help alleviate this;
- Be cautious about the amount of fluids you drink before you head to bed, so you don’t have to wake up to go to the bathroom.
- If you have sleep apnea, a condition where you frequently stop breathing while you’re asleep, seek treatment. Sleep apnea can decrease the quality of your sleep, which may lead to tangles and build-up in your brain.
- Sleep on your side instead of on your back — this lets gravity help your glymphatic system.
- Sleep on your right side — this maximizes the amount of cleaning the glymphatic system can complete.
Sleep may not seem like a big deal, but it’s an important component of your physical health. Research shows that proper sleep makes a huge difference to brain health.
“Only the sleeping brain is capable of efficiently cleaning up the waste products generated during active wakefulness” (Source: National Library of Medicine)
Disclaimer: This article is an information resource only and is not to be used for diagnostic or treatment purposes. You should always consult your health care provider before making any health care decisions.
