Sleep. Your second favorite S word and the one you spend a third of your life doing. And when you’re sleepy, you craaave it! The same way you crave other things essential for your well-being.
What does sleep do for you that makes it so important?
Let’s take a dive.
Fall asleep to turn on your brain’s sewage disposal system.
Your brain is incredibly busy during the day. As a result, you’re left with cell debris and other waste that needs to be removed.
Researchers  have discovered microscopic channels running along side blood vessels in your brain – your central nervous system’s avenue for waste removal.
In 2013, researchers found that this system works by flushing fluid through your brain. During sleep, these channels get larger allowing for this plumbing network to fully operate .
One waste product that gets removed has also been found to accumulate in the brains of those with certain brain disorders.
Does this mean that not getting enough sleep can lead to a build-up of waste and brain disorders?
Research seems to suggest so… .
If you forget to sleep, your brain will forget it all.
Memory can be broken down into three separate phases: acquisition, consolidation and recall.
Acquisition is when you notice something, and absorb that something into your short-term memory.
Consolidation is when that something in your short-term memory, is moved to your long-term memory. This takes place when you asleep.
The last part, recall, is when you decide to remember (or recall) that something from your long-term memory.
So there you go. If you’re not getting enough sleep, you’re not consolidating your memories as well. But that’s not all.
If you’re sleep-deprived, you’ll also struggle with acquisition. Why?
Because when you’re sleep deprived, your attention, your attention span, and your ability to focus won’t work as well .
How sleep can make you less lonely and even save your life
Have you ever tried to function after a sleepless night? Not so much fun, is it?
The tired crankiness isn’t the only reason.
Sleep loss changes activity in parts of your brain responsible for attention, concentration and working memory .
Not surprising then, that lack of sleep increases the probability of a car accident many times over .
When you’re sleep deprived you’re more likely to make unhealthy food choices. A day of this will break your diet. But keep it up, and it might make you obese, or worse ( Type 2 Diabetes, hypertension and stroke are all linked with sleep deprivation) .
And it doesn’t stop there.
The brain-chemical changes caused by sleep deprivation may put you at risk of addiction, depression, anxiety and psychosis .
A recent study showed that sleep deprivation leads to brain changes that encourage loneliness and social isolation – things not at all healthy for your mental state .
All this begs the question: how much sleep do you need?
Whether you need 6 or 8 hours of sleep depends on a genetic variant in your DNA.
Most people need 7-8 hours of sleep each night to avoid the symptoms of sleep deprivation.
But some, only need 5 or 6 and can function at 100% without being tired or cranky.
How are these ‘short sleepers’ different?
These individuals carry a rare ‘short sleeper’ genetic variant of the DEC2 gene.
Do you have this variant and not know it? You might.
If you're a 23andMe customer you can find out by buying the GENEius Performance report.
This report will tell you which variant of the DEC2 you carry.
It will also inform you about other genetic variants you carry associated with working memory, episodic memory, your best learning style, and your ability to focus.
And the report comes with guides to help you improve in all of these areas.
Except for sleep, for that see our tip below.
if you’re having trouble sleeping here is a healthy tip.
1. Hirshkowitz, M., Whiton, K., Albert, S. M., Alessi, C., Bruni, O., DonCarlos, L., ... & Neubauer, D. N. (2015). National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep Health, 1(1), 40-43.
2. Krause, A. J., Simon, E. B., Mander, B. A., Greer, S. M., Saletin, J. M., Goldstein-Piekarski, A. N., & Walker, M. P. (2017). The sleep-deprived human brain. Nature Reviews Neuroscience, 18(7), 404-418.
3. Duffy, J. F., Zitting, K. M., & Czeisler, C. A. (2015). The case for addressing operator fatigue. Reviews of Human Factors and Ergonomics, 10(1), 29-78.
4. Altevogt, B. M., & Colten, H. R. (Eds.). (2006). Sleep disorders and Sleep Deprivation: an Unmet Public Health Problem. National Academies Press.
5. Breslau, N., Roth, T., Rosenthal, L., & Andreski, P. (1996). Sleep disturbance and psychiatric disorders: a longitudinal epidemiological study of young adults. Biological Psychiatry, 39(6), 411-418.
6. Petrovsky, N., Ettinger, U., Hill, A., Frenzel, L., Meyhöfer, I., Wagner, M., ... & Kumari, V. (2014). Sleep deprivation disrupts prepulse inhibition and induces psychosis-like symptoms in healthy humans. Journal of neuroscience, 34(27), 9134-9140.
7. Simon, E. B., & Walker, M. P. (2018). Sleep loss causes social withdrawal and loneliness. Nature Communications, 9-16.
8. Krueger, J. M., Frank, M. G., Wisor, J. P., & Roy, S. (2016). Sleep function: toward elucidating an enigma. Sleep Medicine Reviews, 28, 46-54.
9. Mignot, E. (2008). Why we sleep: the temporal organization of recovery. PLoS Biology, 6(4), e106.
10. Ferry, J. G., & House, C. H. (2005). The stepwise evolution of early life driven by energy conservation. Molecular Biology and Evolution, 23(6), 1286-1292.
11. Zhang S, Zeitzer JM, Sakurai T, Nishino S, Mignot E (2007). Sleep/wake fragmentation disrupts metabolism in a mouse model of narcolepsy. Journal of Physiology, 581, 649–663.
12. Xie, L., Kang, H., Xu, Q., Chen, M. J., Liao, Y., Thiyagarajan, M., ... & Takano, T. (2013). Sleep drives metabolite clearance from the adult brain. Science, 342(6156), 373-377.
13. Jessen, N. A., Munk, A. S. F., Lundgaard, I., & Nedergaard, M. (2015). The glymphatic system: a beginner’s guide. Neurochemical Research, 40(12), 2583-2599.
14. Capellini, I., McNamara, P., Preston, B. T., Nunn, C. L., & Barton, R. A. (2009). Does sleep play a role in memory consolidation? A comparative test. PLoS One, 4(2), e4609
15. Clemens, Z., Fabo, D., & Halasz, P. (2005). Overnight verbal memory retention correlates with the number of sleep spindles. Neuroscience, 132(2), 529-535.
16. Born, J., & Wilhelm, I. (2012). System consolidation of memory during sleep. Psychological Research, 76(2), 192-203.
17. Alhola, P., & Polo-Kantola, P. (2007). Sleep deprivation: Impact on cognitive performance. Neuropsychiatric Disease and Treatment, 3(5), 553-567.
About the Authors:
Daniel Sher is a clinical psychologist, trained at the University of Cape Town and registered with the South African Health Professions Council. His professional interests include neuropsychoanalysis, intersubjective and object-relational approaches; and psychotherapy for people with sexual dysfunctions and Type 1 diabetes.
Igor Rafalovich has in neuroscience research for eight years. He has co-authored research studies in collaboration with top scientists including the Nobel - laureate, Paul Greenguard. As a researcher, he developed his passion for translating innovations in science and technology into solutions for restoring and enhancing cognitive health.