Researchers Continue to Discover the Impact of Poor Sleep on Neurological Health

Sleep quality and brain health go hand-in-hand, yet over 35 percent of American adults are considered to be “short sleepers.” This means that on average, they get less than 7 hours of sleep per night. According to the CDC, short sleepers are also more likely to be physically inactive, smokers, and obese.

When it comes to brain health, the importance of sleep should not be underestimated. A highly complex (and busy) organ, your brain accumulates waste. Studies have shown that in order to enhance brain cleaning, you should get regular exercise, eat a diet that is rich in healthy fats, vegetables, and antioxidants, and most importantly, prioritize sleep.

Now, researchers are finding that sleep not only supports waste removal but also prevents decline. In fact, during sleep it may actually allow your brain to effectively clean out plaques — a hallmark of Alzheimer’s.

The More Waste, the Greater Your Risk of Alzheimer’s

The link between optimal sleep and neurological health has long been studied. However, it is only recently that scientists have discovered how critical this relationship is with regards to disease. In April 2017, researchers discovered a new type of brain cell in zebrafish. This cell was essentially a “scavenger” cell.

Since zebrafish share many of the same cell types as humans, neuroscientists shifted their attention to how cleaning systems diminish during the aging process. To combat these effects, sleep has become a key area of interest. After all, your glymphatic system remains active while you sleep.

This is due to your glial cells, which surround your neurons. As you sleep, these cells shrink, influencing the glymphatic flow. As the space between each cell increases (by up to 60 percent), more fluid is able to flow through, impacting waste clearance. Unfortunately, poor waste removal has been linked to a greater risk of Alzheimer’s and other neurological diseases.

The Relationship Between Sleep and Plaques

Since 2001, the University of Wisconsin-Madison has been regularly testing more than 1,500 people. When they initially signed up, these individuals were between the ages of 40 and 65. Although none of the participants showcased symptoms of dementia. 70 percent had a family history of Alzheimer’s.

Testing these individuals for signs of memory loss, as well as the presence of amyloid-beta (which form into plaques), the researchers were able to better understand a range of variables. Based on various questionnaires, the inquiries about sleep have been particularly eye-opening.

Brain scans and recorded sleep quality led to the discovery that poor sleep increased biological markers of Alzheimer’s. In a 2015 study, it was reported that poor sleep was associated with more amyloid-beta plaques. The researchers later found that poor sleep also increased inflammation and the protein tau.

Does Alzheimer’s Cause Poor Sleep, or Does Poor Sleep Cause Alzheimer’s?

At this point, there are still many gaps in the research. Some experts believe that poor sleep may be an early warning sign of Alzheimer’s. However, others are confident that poor sleep contributes to the development of the disease. It is the classic chicken-and-egg problem.

Although this problem is not fully understood, it is clear that even on bad night sleep can disrupt the brain. One 2018 study found that after just one night of sleep deprivation, amyloid-beta levels rose in most of the subjects tested. Researchers will continue to study this link, as the role of sleep quality may lead to a successful, non-invasive intervention.

The BrainTest® App

If you are currently concerned about your level of cognition, it is important that you intervene as soon as possible. That is why we have developed the BrainTest® app, a screening tool that can help you detect the early warning signs of Alzheimer’s, dementia, and other cognitive impairments.

For more information on sleep and brain health, please refer to the following:


Krista Hillis has a B.A.Sc degree, specializing in neuroscience and psychology. She is actively involved in the mental health and caregiving community, aiming to help others. Krista is also passionate about nutrition and the ways in which lifestyle choices affect and influence the human brain.

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