Published 12/16/2013. Updated 1/4/2014.
As we all are painfully aware when we aren’t getting enough of it, sleep is essential to our health. Sleep deprivation compromises our immune systems just as illness, physical and emotional stress do. Though we’re not aware of it, helpful bodily processes are taking place as we sleep.
The most important is the removal of potentially neurotoxic waste from the central nervous system. The brain has its own waste management system, called the glymphatic system, which is similar to the body’s lymphatic system. This system pumps cerebral spinal fluid through the brain’s tissues, flushing waste into the body’s circulatory system and from there into the liver, where it’s eliminated.
In aid of this flushing process, the sleeping brain’s cells shrink about 60 percent, allowing for more efficient waste removal and helping ensure metabolic homeostasis. Perhaps we feel restored and can think more clearly after a good night’s sleep because toxic waste products, built up while we’re awake, have been removed from our central nervous systems. (Xie, 2013)
Lack of adequate sleep is also known to have a worsening effect on chronic diseases such as Alzheimer’s, Multiple Sclerosis and Parkinson’s (all are autoimmune neuro-degenerative diseases), gastrointestinal tract disorders, kidney disease, childhood behavioral problems and many others.
A clue to the important relationship between sleep and disease: Amyloid-beta proteins, the ones that create the plaque typically seen in Alzheimer’s patients’ brains, get removed in significantly greater amounts during sleep. One interesting implication of this finding is that treatments for Alzheimer’s might be more helpful if given before bedtime. (Xie, 2013)
When the gut is inflamed, infected or suffering from dysbiosis in some other way, major stress gets put on the adrenals – tiny but powerful endocrine glands that sit atop the kidneys. They manufacture and secrete hormones such as steroids, cortisol, cortisone, estrogen, progesterone and testosterone as well as chemicals such as adrenaline (epinephrine), norepinephrine and dopamine.
The ever-alert adrenals are in constant, sensitive communication with the gut flora, so an imbalance in one will affect the other. The adrenals have a regulating effect on every organ, gland, tissue and cell in the body as they work to maintain homeostasis. Their main purpose is to allow the body to deal with stress of any kind. They even influence the way we think and feel. If stress becomes chronic, the adrenals can become overworked, eventually exhausting the immune system.
Stress – from any cause – is the most common cause of poor sleep. When cortisol levels rise and fall erratically, especially when combined with a nutrient-poor diet, the adrenals become fatigued – they can actually wear out. In adrenal fatigue, cortisol levels are too high at night (preventing sleep) and not high enough in the morning to keep us functioning well through the day. (AdrenalFatigue.org, 2013)
AdrenalFatigue.org (2013). Adrenal function. See http://www.adrenalfatigue.org/adrenal-function
Xie, L. et al. (2013). Sleep Drives Metabolite Clearance from the Adult Brain, Science 342:6156, 373-377.
A version of this page content will appear in my forthcoming 2014 Oriental Medicine Journal article THE MICROBIOTA-GUT-BRAIN AXIS: The constant two-way communication between our guts and our brains.
© Copyright 2013-2014 Joan Rothchild Hardin. All Rights Reserved.