While sleep researchers are constantly learning more about why we need sleep, one thing has been clear since the beginning of time: If we don’t get enough of it, we falter. Sleep deprivation has been identified as a factor in countless tragedies including friendly fire incidents in the military, train accidents, plane crashes, industrial and automobile accidents, and medical misjudgments.
Some of us have personally experienced the agony of sleep deprivation when pulling all-nighters in school, taking care of a newborn baby, doing shiftwork, driving for long periods of time, or trying to meet a looming deadline. The effects of sleep deprivation may be subtle at first: our thinking may be a bit more sluggish, our memory not quite as precise, and our movements a bit slower. However, the impact often quickly accelerates, and before we know it we may feel like we are moving through the world in a slow-motion state of clumsiness and increasing confusion.
What is less obvious is that sleep deprivation actually impairs our ability to process and store the memories that we form during our waking hours. Furthermore, if sleep deprivation is chronic (occurring over months or years), it may also be a risk factor for Alzheimer’s disease.
Just this summer, researchers at Washington University found that disrupted sleep led to increased levels of two proteins in the brain associated with Alzheimer’s – beta amyloid and tau. In the study, beta amyloid levels increased after just one night of sleep deprivation, and tau levels increased after one week of sleep deprivation. Although it is likely that the brain has a mechanism for correcting for such effects of short-term sleep deprivation, this finding may provide a possible explanation for the link between chronic sleep deprivation and Alzheimer’s.
Related findings in a mouse model of Alzheimer’s showed that not only was beta amyloid significantly higher in mice who were sleep deprived, but the rate at which beta amyloid was cleared from the brain doubled during sleep. Although this brain-cleaning mechanism has not yet been observed in humans, it is interesting to note that beta amyloid levels in humans increase throughout the day, but decrease during sleep. These results – when combined with data showing that sleep is necessary to successfully remember information – provide growing support for the link between sleep and brain health.
Because sleep is often the first casualty of an overextended schedule, many of us do not feel well rested and refreshed on a regular basis. So, how do we give our brain the sleep it needs to function at optimal levels?
1. Figure out how much sleep you need to feel well rested. Although the average person requires 7-9 hours of sleep, many individuals need more or less time. How do you know how much is optimal for you? If you feel refreshed, awaken without an alarm clock, feel alert throughout the day (without excessive use of caffeine), and do not fall asleep immediately after your head hits the pillow, chances are you are getting enough sleep. If you are not getting enough sleep, gradually increase the amount of time you sleep until you feel well rested, and prioritize getting that amount on a regular basis.
2. Schedule in “down-time” prior to bedtime. Engaging in a relaxing pre-bedtime ritual helps signal the body of the upcoming transition to sleep, and improves sleep quality. Calming activities might include dimming the lights, reading, and listening to soft music. Also consider turning off blue-light devices about an hour before bedtime (e.g. televisions, cell phones, tablets), given that blue light has been shown to interfere with melatonin, a sleep-inducing hormone.
3. If you can’t fall asleep after 10 minutes, get up and do something relaxing. When we lie in bed and think about things for long periods of time before falling asleep, our brain unwittingly links lying in bed with thinking. As a result, we may automatically go into “thinking” mode rather than “sleeping” mode when we lie down the next time. To teach your brain to pair lying in bed with sleeping, if you cannot fall asleep after 10 minutes, get up and do something calming such as reading or meditating. Then return to bed when you feel groggy. Repeat this as many times as necessary in a given night. This recommendation may seem paradoxical, but it really works! Over time, your brain will more readily go into sleeping mode rather than thinking mode when you lie down.
Prioritizing optimal sleep helps your brain function faster, remember better, and just may help to minimize the risk of Alzheimer’s. Optimal sleep also helps reduce the risk of accidents, and maximizes mood, quality of life, and immune functioning. With all of these benefits, it’s time to prioritize getting some Zz’s!
David M. Holtzman et al. Slow wave sleep disruption increases cerebrospinal fluid amyloid-β levels. Brain, July 2017 DOI: 10.1093/brain/awx148