Sleep, Cognition And The Accelerated Onset Of Neurodegeneration
We seriously do need to review the mantra of “sleep is for the weak”. Because it really isn’t.
Even before the COVID-19 coronavirus came to be, the United States Centers For Disease Control And Prevention (CDC) declared insufficient sleep to be a public health epidemic.
According to the American Sleep Apnea Association,
Sleep problems, whether in the form of medical disorders or related to work schedules and a 24/7 lifestyle, are pervasive. In America, 70% of adults report that they obtain insufficient sleep at least one night a month, and 11% report insufficient sleep every night.
It is estimated that sleep-related problems affect 50 to 70 million Americans of all ages and socioeconomic classes. Sleep disorders are common in both men and women; however, important disparities in prevalence and severity of certain sleep disorders have been identified in minorities and underserved populations.
Additionally, people are chronically sleep deprived as a result of demanding lifestyles and a lack of education about the impact of sleep loss. Sleepiness affects vigilance, reaction times, learning abilities, alertness, mood, hand-eye coordination, and the accuracy of short-term memory. Sleepiness has been identified as the cause of a growing number of on-the-job accidents, automobile crashes and multi-model transportation tragedies.
The odds of being sleep deprived (less than 6 hours a night for adults) has increased significantly over the past 30 years as the lines between work and home have become blurred and digital technology has firmly become part of our lifestyles. National data shows that poor sleep health is a common problem with 25 percent of U.S. adults reporting insufficient sleep or rest at least 15 out of every 30 days. The National Institutes of Health predicts that America’s sleep debt is on the rise and that by the middle of the 21st century more than 100 million Americans will have difficulty falling asleep.
As we can see, there are many issues associated with a lack of sleep, especially with demanding lifestyles. Now that we are in the state of a global pandemic, there are other factors that will hinder our ability to sleep properly. Stressors such as social isolation, a worry about finances and finding work (especially for people who were collateral damage layoffs) and a worry about one’s health (especially people who are deemed to be at higher risk of dying from a COVID-19 infection) can cloud our minds and make it even more difficult to sleep.
This COVID-19 pandemic can throw many people into a state of zombification. All these stressors can also cause our hair to go white more prematurely.
But what else do we have to look out for?
The problem with sleep deprivation is that it doesn’t just affect our “vigilance, reaction times, learning abilities, alertness, mood, hand-eye coordination, and the accuracy of short-term memory.” There are real, long-term health consequences due to lack of adequate sleep.
We know what it feels like to wake up in the morning after having not slept properly the night before. The grumpiness, irritation and the need for coffee is there…
And so is the inflammation.
In this article, it is said that:
Approximately one-third of adolescents and adults in developed countries regularly experience insufficient sleep across the school and/or work week interspersed with weekend catch up sleep.
As this sleep disruption becomes a chronic, habitual pattern, there will be an increased expression of pro-inflammatory cytokines in the brain. These include cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-α).
Too much of these pro-inflammatory cytokines in the brain can signal the neurons in our brain to commit suicide prematurely via the process of neuronal death called apoptosis. When a person’s brain has insufficient neuronal activity for cognitive function… they’d end up with the disease commonly known as Alzheimer’s.
Hence, getting adequate sleep is extremely important for preventing the development of Alzheimer’s disease in the long term. But we do need to understand that it isn’t about the isolated days when we experience sleep deprivation from different factors.
It’s about a long-term, sustained sleep deprivation that can accelerate the onset of Alzheimer’s.
Moreover, our immune response to a viral infection is worsened.
It is said in this article that:
…In modern times, chronic social threats can drive the development of sleep disturbances in humans, which can contribute to the dysregulation of inflammatory and antiviral responses.
When we’re stressed, we can’t relax or sleep properly. This sleep deprivation causes us to be stressed even more. The stress-sleep deprivation cycle amplifies over time, leading to an even greater release of pro-inflammatory cytokines. This is precisely how the inflammatory and antiviral response becomes dysregulated.
As a result, the immune system’s response to a virus infection is weakened (there is additional stress placed on the immune system when responding to an infection), and the possibility of hitting an amplified loop with a concentration of pro-inflammatory cytokines that are high enough to cause a cytokine storm within a person is even higher.
And that’s one of the plausible reasons why young adults who are seemingly healthy do end up developing cytokine storms from a COVID-19 infection. It is all too easy to look “young and healthy”, but how well is the inflammatory response regulated within the body? We can’t really tell until it’s too late,
What happens as we sleep?
This article summarises the biochemistry in our body as we sleep:
In the dark, norepinephrine is released by the superior cervical ganglion to stimulate the pineal gland in the brain to release melatonin into the blood. The pineal gland synthesises melatonin sequentially from the amino acid tryptophan, which is converted into serotonin as an intermediate. All of this activity (and our circadian rhythm) is regulated by the suprachiasmatic nucleus in the brain.
When this circadian rhythm is not well regulated, as mentioned in this article:
Disruptions of circadian rhythms are associated with mood disorders and serotonin has been implicated in their pathophysiology.
When serotonin is implicated, the subsequent synthesis of melatonin will be affected too.
How else does melatonin production get affected?
In the presence of an injury, where there is acute inflammation, the pineal gland (PG) releases less melatonin, the neuro-modulator that contributes to our ability to sleep — and that is one of the reasons why we find it more difficult to sleep properly when we are injured or sick. The immune cells are stimulated to release their own melatonin into the tissues, as melatonin is both a potent antioxidant and anti-inflammatory. When the inflammation signal is resolved, the PG starts producing melatonin again.
However, in the case of sleep deprivation, one faces an accumulation of pro-inflammatory cytokines in their blood. The problem with this accumulation of the pro-inflammatory cytokines is that it will affect our immune system’s response to a viral infection.
The problem, also, then, is that a case of chronic sleep deprivation will cause an existing sleep problem to worsen.
Because we need the pineal gland to release melatonin into our blood so that we can sleep properly.
When the concentrations of the pro-inflammatory cytokines in our blood are higher, the immune cells will release their own melatonin to counteract the effects of the inflammation — and the immune cells will continue producing melatonin daily (while shutting out the pineal gland’s production of melatonin) when the inflammation signal is stronger than usual.
Therefore, a person who is chronically sleep deprived, and who has a chronic inflammatory illness is very likely to have a sleeping problem. They will seek to sleep, and yet getting consistent, good sleep will elude them.
The importance of quality sleep, for so many reasons, cannot be overstated!
Do feel free to check out 10 Nutrients That Support A Good Sleeping Cycle to see what nutrients can support one’s sleep quality!
Joel Yong, PhD, is a biochemical engineer/scientist, an educator and a writer. He has authored 5 ebooks (available on Amazon.com in Kindle format) and co-authored 6 journal articles in internationally peer-reviewed scientific journals. His main focus is on finding out the fundamentals of biochemical mechanisms in the body that the doctors don’t educate the lay people about, and will then proceed to deconstruct them for your understanding — as an educator should.
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