Sleep, We know we need it but why?

IMG_6003.jpg

So we all know we need it right. It feels os nice and rejuvenates us. It allows our bodies to restore and repair, heal and grow. But what’s interesting is we don’t 100% understand the biochemistry of it. Not that we need to KNOW all the answers, but it’s interesting and worth exploring more… the fun in finding understanding.

So this idea came about while driving in the car today I was listening to a podcast from 2013. Latest in Paleo with Angelo Coppola and during the podcast he discusses how when we sleep there is a flushing that happens, like emptying the waste basket at the end of the work day. This allows for us to feel more rejuvenated.

  • Sleep Scrubs the Brain Clean

    • NBC News: http://www.nbcnews.com/health/good-nights-sleep-scrubs-your-brain-clean-researchers-find-8C11413186

      “The scientists had used two-photon microscopy — a new imaging technology that allows scientists to see deep inside living tissue — to peer into the brains of mice, which are remarkably similar to human brains.

      They found that the glymphatic system pumps cerebral spinal fluid, CSF, through the spaces around the brain cells, flushing waste into the circulatory system, where it eventually makes its way to the liver.

      Their latest research, also in mice, used the same technology to focus on the timing of the glymphatic system. The researchers discovered that during sleep brain cells contract, increasing the space between the cells by as much as 60 percent and allowing the spinal fluid to wash more freely through the brain tissue.”

    • Related study (Thanks Whole 9 SouthPacific): http://ajpendo.physiology.org/content/305/7/E890

    • This study was to “evaluate in a comprehensive way the effects of extended recovery sleep following mild sleep restriction on 24-h secretion of hormones/cytokines in parallel with sleepiness and performance in young men and women. It appears that 2 days of extended recovery sleep over the weekend reverses the impact of one work week of mild sleep curtailment on daytime sleepiness, fatigue, and IL-6 levels and reduced cortisol levels. However, 2 recovery nights were not sufficient to improve performance, suggesting that complete performance recovery following one work week of sleep restriction may require more than 2 days of extended sleep.”

This got me looking further and what’s interesting is history tends to repeat itself, just like news eventually repeats too.

  • A newer study released November 2019 in the journal of Science https://science.sciencemag.org/content/366/6465/628

    Abstract:  Sleep is essential for both cognition and maintenance of healthy brain function. Slow waves in neural activity contribute to memory consolidation, whereas cerebrospinal fluid (CSF) clears metabolic waste products from the brain. Whether these two processes are related is not known. We used accelerated neuroimaging to measure physiological and neural dynamics in the human brain. We discovered a coherent pattern of oscillating electrophysiological, hemodynamic, and CSF dynamics that appears during non–rapid eye movement sleep. Neural slow waves are followed by hemodynamic oscillations, which in turn are coupled to CSF flow. These results demonstrate that the sleeping brain exhibits waves of CSF flow on a macroscopic scale, and these CSF dynamics are interlinked with neural and hemodynamic rhythms.

>> basically this study confirmed what was earlier observed in mice.


What are the other benefits of sleep?

“Getting enough quality sleep at the right times can help protect your mental health, physical health, quality of life, and safety. ... During sleep, your body is working to support healthy brain function and maintain your physical health. …. Ongoing sleep deficiency can raise your risk for some chronic health problems. It also can affect how well you think, react, work, learn, and get along with others. https://www.nhlbi.nih.gov/health-topics/sleep-deprivation-and-deficiency

From: https://www.sleepfoundation.org/articles/why-do-we-need-sleep We tend to think of sleep as a time when the mind and body shut down. But this is not the case; sleep is an active period in which a lot of important processing, restoration, and strengthening occurs. Exactly how this happens and why our bodies are programmed for such a long period of slumber is still somewhat of a mystery. But scientists do understand some of sleep's critical functions, and the reasons we need it for optimal health and wellbeing.

One of the vital roles of sleep is to help us solidify and consolidate memories. As we go about our day, our brains take in an incredible amount of information. Rather than being directly logged and recorded, however, these facts and experiences first need to be processed and stored; and many of these steps happen while we sleep. Overnight, bits and pieces of information are transferred from more tentative, short-term memory to stronger, long-term memory—a process called "consolidation." Researchers have also shown that after people sleep, they tend to retain information and perform better on memory tasks. Our bodies all require long periods of sleep in order to restore and rejuvenate, to grow muscle, repair tissue, and synthesize hormones.

Seems like the more I search, the more what information says is that tis more to its a link in the prevention of several diseases and conditions. https://www.health.harvard.edu/press_releases/importance_of_sleep_and_health

The Harvard Women's Health Watch suggests six reasons to get enough sleep:

  1. Learning and memory: Sleep helps the brain commit new information to memory through a process called memory consolidation. In studies, people who'd slept after learning a task did better on tests later.

  2. Metabolism and weight: Chronic sleep deprivation may cause weight gain by affecting the way our bodies process and store carbohydrates, and by altering levels of hormones that affect our appetite.

  3. Safety: Sleep debt contributes to a greater tendency to fall asleep during the daytime. These lapses may cause falls and mistakes such as medical errors, air traffic mishaps, and road accidents.

  4. Mood: Sleep loss may result in irritability, impatience, inability to concentrate, and moodiness. Too little sleep can also leave you too tired to do the things you like to do.

  5. Cardiovascular health: Serious sleep disorders have been linked to hypertension, increased stress hormone levels, and irregular heartbeat.

  6. Disease: Sleep deprivation alters immune function, including the activity of the body's killer cells. Keeping up with sleep may also help fight cancer.