Sleep and Alzheimer's

Chronic Poor Sleep Linked With Alzheimer's

Article Summary

• During sleep the brain refreshes itself from the day before, it cleans out waste products and replenishes nutrients it uses to function.


• Poor sleep disrupts this process and leaves the brain with harmful waste products and insufficient nutrients for the brain's complex functions.


• An occasional night of poor sleep won't lead to any damage, but chronic sleep conditions, like sleep apnea, which can last for years, or even decades can lead to lasting brain damage and a significantly higher risk for developing Alzheimer's disease.


Sleep has always been known to play a crucial role in our health. Recently, multiple studies have shown that poor sleep significantly increases the likelihood for developing Alzheimer’s.

The Function of Sleep


During normal sleep the human brain passes through 5 stages, 1,2,3,4 and Rapid Eye Movement (REM) sleep.


As you progress through these stages, known collectively as the sleep cycle, your brain performs various functions, repairing and preparing itself for the next day. Different functions occur during each stage. The deeper stages (3 and 4) are responsible for cleaning the brain. During this cleaning a fluid circulates through the brain removing toxins, including those toxins associated with the development of Alzheimer’s disease.

The Stages of the Sleep Cycle, during a healthy night's sleep you will pass thru this cycle 5 to 8 times.

When an individual is woken while sleeping, the sleep cycle is disrupted. Upon resuming sleeping the cycle resets at the beginning, stage 1. Waking up once or twice at night isn’t enough to cause significant disruption to the sleep cycle, but individuals who frequently have difficulty sleeping; especially those with sleep apnea should be aware of the damage done to their brain.


The damage is caused by insufficient time in the deeper stages of sleep. The toxins which are normally removed are allowed to accumulate, impairing mental functioning and increasing the risk for developing Alzheimer’s.


A study conducted in 2013 showed that 43 percent of individuals suffering from dementia had a form of sleep apnea, compared to 4 percent of similarly aged individuals without dementia.


An additional study at the Washington University in St. Louis showed that the amyloid plaques associated with Alzheimer’s develop more quickly in the brains of sleep-deprived animals.


Who Is At Risk?


The individuals at greatest risk are those suffering from sleep apnea, a chronic sleep disorder in which the individual stops and starts breathing during the night. The constant sleep disruption associated with sleep apnea prevents the individual from moving into the ‘deeper’ stages of sleep, preventing the cleansing process from happening.


Sleep apnea is often difficult for the individual to recognize as they are not aware of the disruptions which happen at night; more than 80 percent of individuals with sleep apnea are unaware of their condition.


Symptoms of Poor Sleep, Especially Sleep Apnea:


  • Snoring loudly

  • Feeling tired even after a complete night’s sleep

  • Waking with a headache

  • Waking gasping for breath, or if your partner notices you gasping for breath while asleep


More information on Sleep Apnea, its symptoms, and treatments can be found at the American Sleep Apnea Association.


Ensuring a Healthy Sleep


Getting a healthy night’s sleep is crucial for a healthy brain; below we list some of the best ways to ensure a good night’s sleep.


Avoid Caffeine, Alcohol, and Nicotine before bed. All three of these substances disrupt the normal sleep cycle. 


- While alcohol does allow individuals to fall asleep more easily, numerous studies have shown that it negatively impacts your quality of sleep. Allow enough time for alcohol to be processed before going to bed, at least few hours between your last drink and bed time.


- Caffeine functions as a stimulant which makes falling asleep more difficult and decreases the quality of the sleep, similar to alcohol. Caffeine takes longer than alcohol to be processed, so your last caffeinated beverage should be consumed no less than six hours before bedtime.


- Nicotine, similar to caffeine, functions as a stimulant which can make falling asleep more difficult and decreases overall sleep quality. Scientists debate whether there is a cut off time for nicotine before bed as the presence of nicotine causes sleep difficulty, but withdrawal symptoms associated with its absence also cause sleep difficulty. If you’re concerned about the health of your brain, you should consider quitting nicotine all together.


Go To Bed And Get Up At A Regular Time


Go to bed and get up at the same time each day, even weekends and vacations. By setting consistent sleep and wake schedules you are setting your body’s circadian rhythm, our internal ‘clock’ responsible for determining which parts of the day we are alert, and which parts we are tired. By setting your circadian rhythm and sticking to it, you will feel more alert during the day and fall asleep faster at night.


Exercise And Sleep


The benefits of exercise are immense and sleep quality is no exception. Exercise aids in healthy sleep, enabling us to fall asleep faster and spend more time in the recuperative deep stages of sleep.

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