By Dr. Dana Myatt
Like breathing, sleep is an “essential” human requirement. “Essential” means that your body must have it and you would die without it.
How long can a person go without sleep before death ensues? The jury is still out on this. But death isn’t the biggest problem of sleep deprivation because the body will eventually take “microsleeps.” Microsleep refers to brief moments of sleep that occur when you’re normally awake.
You can’t control microsleep, and you might not even be aware of it. For example, have you ever driven somewhere and then not remembered part of the trip? If so, you may have experienced microsleep.
Even if you’re not driving, microsleep can affect how you function. If you’re listening to a lecture for example, you might miss some of the information or feel like you don’t understand the point. In reality though you may have slept through part of the lecture and not been aware of it.
Exactly how long a person can go without sleep isn’t fully known, but we do know that extreme sleep deprivation causes hallucinations, automobile accidents, job injuries and memory impairment.
Why does the body need sleep?
Researchers have found that the brain clears out waste material accumulated throughout the day as we sleep at night. But like many things the brain does, it does this “housekeeping” a little differently than the rest of your body.
Other parts of the body have the lymphatic system to clear out waste products but the brain does not have lymphatic channels. Instead, the brain relies on astrocytes – specialized star-shaped nerve cells that are bathed in cerebrospinal fluid. The astrocytes have many other jobs, but a big responsibility for them is to express a substance called astrocytic aquaporin-4 which lets the cells “gather up the trash” and pass it to the cerebrospinal fluid, allowing it to carry daytime debris away. When we sleep, neurons temporarily shrink and allow for more cerebrospinal fluid to wash over our brains. In other words, sleep is when our brains clean out daytime garbage.
“This study shows that the brain has different functional states when asleep and when awake,” said U of R researcher Maiken Nedergaard. “In fact, the restorative nature of sleep appears to be the result of the active clearance of the by-products of neural activity that accumulate during wakefulness.”
“Clean sleep” results in a more complete clearing of waste proteins from the brain, but “dirty sleep” has the opposite effect. Some of the debris cleared from the brain during sleep includes beta amyloid, the junk that accumulates in the brain and may be the cause of Alzheimer’s.
So, in addition to many other necessities of sleep — physical restoration and healing of muscles, endocrine (hormonal) balancing, R.E.M. or “dream sleep” for mental health — the brain needs sleep in order to take out the garbage.
Are You Getting Dirty Sleep?
Dirty sleep happens when we fail to get enough sleep, or fail to get sufficient deep sleep. Fortunately, most of the causes of poor sleep are within an individual’s control.
1.) Bedtime/wake time. The body manufactures melatonin during sleep unless light interferes with its production. Melatonin functions as an antioxidant in the brain and central nervous system and its production begins as the setting of the sun stimulates the pineal gland. This normally occurs in most people around 9:00 PM, with sleep usually occurring around an hour later by 10:00 PM. Solution? Set a regular bedtime, and stick with it.
2.) Light after sundown. The pineal gland, a tiny gland deep in our brains that is connected to the eyes, is responsible for producing the sleep and antioxidant hormone melatonin. It begins to churn our this important substance in response to the ”dimming of the lights” as the sun sets. If the light doesn’t dim, the pineal gland doesn’t know to produce melatonin. And, once the light does dim and it begins its work any amount of white light promptly shuts it off – by making it think it is dawn.
Since humans evolved over millions of years sleeping in the safety of the flickering subdued orange light of a cozy fire, we tolerate low levels of this color of light after dark. But exposure to white light (or, more specifically, light that contains specific frequencies of blue light – like daylight or televisions, or computer monitors, or full-spectrum light bulbs) during the hours before bedtime will seriously disrupt melatonin production, making natural sleep very difficult.
Solution? When the sun goes down you need to start lowering the light levels in your environment as well – not an easy task in our modern world, but possible if you remember that it is the harsher blue-white lights that disrupt melatonin production. Try candle light or soft incandescent lights, limit your TV watching for the hour or so before bed, and limit exposure to bright phone, tablet, and computer screens before bed.
If you must get up at night try to avoid turning on bright lights – consider using low-wattage incandescent nightlights.
3.) Related to white light in the evening is the twinkling of myriad electrical and electronic devices that seem to litter our sleep spaces. Little red lights, green lights, blue lights, all glowing and twinkling and blinking… Not only are the lights distracting, many of these devices also emit occasional noises – beeps, chirps, hums, whirs…
The solution? Do yourself a favor and banish all the electronics from your sleep space. Unless you are a surgeon on call, or have some equally important reason to receive calls after bedtime, turn the phone off. Shut the tablet and computer down for the night.
Many people also believe that there may be a sleep-disturbing effect from all the EMF (electromagnetic fields) created by these devices in proximity to your sleep area.
4.) What you eat and drink in the evening matters: That nice sweet dessert may help you feel satisfied and sleepy when it raises your blood sugar, but when your blood sugar crashes a few hours later and your body responds with a shot of adrenalin you are going to find yourself wide awake with the jitters.
Try a little snack bite of protein instead, if you really must have a before bed snack.
5.) What you see before you sleep matters too: Upsetting or stressful imagery immediately before sleep can be unsettling and make it difficult to get to sleep, and can give your brain plenty of unpleasant material to craft its dreams from. The 10:00 news with horrific images of war-torn countries, detective shows with nasty people doing ugly things to each other, zombie horror shows dripping with gore… are these really the sights that you want to try to fall asleep to?
A better bet might be something uplifting or soothing. Pleasant short stories, or poetry, or spiritual reading or meditation. And remember, like I said in point 2, that TV screen, with its bright light, is preventing the normal production of melatonin.
6.) Oversleeping. Those who insist on sleeping in late in the morning are setting themselves up to seriously disturb their circadian rhythms. Further, late waking combined with daytime napping can leave you feeling wakeful in the evening, and wanting to stay up beyond a healthy bedtime. It can easily become a vicious circle.
So, you are retired with not much to do and feel like there is no reason to get up in the morning? Make a reason! Get up and get moving – the physical activity throughout the day will also contribute better sleep at night.
7.) Drugs and medications: Many prescription drugs can cause insomnia and poor sleep here are some of the more common offenders:
- SSRI antidepressants
- ACE inhibitors
- ARBs (Angiotensin II-receptor blockers)
- Cholinesterase inhibitors
- Antihistamines and H1 antagonists
- Glucosamine/chondroitin (if taken late in the day)
- Statins (cholesterol drugs)
Non-prescription drugs can do the same. And recreational drugs can too: even alcohol can cause problems – in smaller amounts alcohol has a stimulating effect and more than a few drinks, while sedating for sure, can cause a rebound insomnia when the effect wears off. A pre-dinner drink? Sounds good. A glass of wine with dinner? Also good. A few drinks “to put you to sleep”? Not so good…
8.) Sleep medications: You really aren’t taking a sleeping pill are you? If you are then you obviously haven’t read our previous HealthBeat News articles describing the dangers of these drugs. Do yourself a favor and drop the sleeping pills.
9.) Many people complain that muscle cramps at night disturb their sleep. Something as simple as some extra magnesium can prevent cramps and can be relaxing overall. Magnesium oil, actually a thick brine of magnesium salts, can provide nearly instant relief for many muscle cramps when rubbed over the affected area.
So it turns out that when we sleep our brain takes that time to clean out the build-up of brain junk we accumulate during our waking hours. Sleep is pretty much necessary for our body’s mental street-cleaners to come out and do their work. When cells do their daily cell-type work, they produce waste products. The rest of the body has this waste cleared out by the lymphatic system, but the brain is not connected to that, so it needs another way to clear out the waste.
The brain has it’s own garbage men, carried on the waves of cerebrospinal fluid, who surf the leftovers straight down to your liver for elimination. As it turns out, the brain’s garbage men move twice as fast when you’re sleeping, because your neurons shrink by half, making the fluid channels wider.
You’re not going to have a “Dirty Mind” now, are you?
References and further reading:
Sleep Drives Metabolite Clearance from the Adult Brain
Lulu Xie et. al.,Science 18 Oct 2013:, Vol. 342, Issue 6156, pp. 373-377, DOI: 10.1126/science.1241224
10 Types of Meds That Can Cause Insomnia, AARP
Posted in Family Health, Mental Health, Senior Health | No Comments »