Getting enough sleep will have a big impact on mental, metabolic, cardiovascular, cognitive health, and much more.
Ideally, sleep accounts for about a third of our day. Contrary to what some might think, these hours are far from wasted. In fact, sleep serves much more than just energy for the next day; it's a fundamental pillar of health.
Let's take a closer look at how sleep contributes to a healthy life and how our lifestyle habits can help us optimize our sleep to reap all its benefits.
How sleep influences our health
Mental health
Although in the short term, lack of sleep seems to cause an improvement in mood through changes in serotonin, dopamine and their receptors, these effects are only very temporary. Not all the mechanisms are yet fully understood, but the studies are clear, there is no doubt that sleep is involved in many mental health disorders. In the long term, there seems to be a decrease in serotonin levels and changes in its receptors in different regions of the brain. 1 Sleep also allows for regulation of dopamine and different dopaminergic receptors, which can influence wakefulness, motivation and concentration. 2 Additionally, when we are tired, the amygdala in our brain tends to be more active, which can create difficulty regulating our emotions and an increase in anxiety and irritability. 3
Metabolic health
To compensate for the energy deficiency caused by lack of sleep, the body will alter its appetite regulation by increasing the hunger hormone ghrelin and decreasing the satiety hormone leptin. This increases hunger, but does not make us feel full. Adiponectin secretion will also increase, making adipose tissue more sensitive to insulin and therefore more likely to store more fat. 4 We will also tend to seek out foods that are more energy dense and easily accessible, such as fast sugars and fats that will be found in foods that are often less healthy. 3 Studies also show that lack of sleep significantly increases insulin resistance, the cause of what is called metabolic syndrome. One study found that after just six nights of four hours of sleep, study participants were 40% less effective at managing glucose, similar to prediabetes. 5
Cellular repair
At night, during the deep slow-wave sleep stages (mainly NREM 3), growth hormone is released in greater quantities, allowing cellular repair. 6 It stimulates the repair of tissues such as muscles and promotes their growth, it increases the production of collagen in the skin, bones and joints. It is therefore essential to reach these stages of sleep, because although growth hormone is also produced in peaks in smaller quantities during the day, the vast majority of its secretion occurs at night.
Cognitive health
Sleep influences cognitive health in several ways. First, especially during the deep and REM sleep stages, with the help of acetylcholine, memory and learning will be consolidated.7 In addition, in the brain there is what is called the glymphatic system, referring to the lymphatic system, but also to the glial cells that play a key role in it. This system, activated almost exclusively during sleep, is responsible for cleaning the interstitial fluid of the brain parenchyma to rid it of metabolic waste such as beta-amyloid, which is involved in Alzheimer 's disease.8
Cardiovascular health
Unfortunately, the day after the time change, one study found an increase of up to 25% in the number of heart attacks. 9 In fact, poorer quality and less sleep increases cortisol levels. This causes blood vessels to contract, which affects blood pressure, but can also reduce blood flow to heart vessels already narrowed by atheromatous plaques. High cortisol will also increase chronic systemic inflammation in addition to increasing blood sugar, which can in turn cause inflammation in blood vessels and increase the risk of cardiovascular disease. 5
What to do to improve the quality of your sleep
Have a regular schedule, that is, go to bed and get up at the same times every day, even on weekends. 10
Indeed, some people, when they go to bed later on weekends, can feel the impacts for the following days. It is also important to go to bed early enough before midnight to maximize the achievement of restorative sleep cycles. The architecture of our sleep changes during the night, the first hours will have more deep slow-wave sleep, promoting above all physical recovery and cellular repair. At the end of the night, it is REM sleep that will be dominant and which will allow the consolidation of memory and learning. 11
Promote the darkest possible environment in the bedroom and limit exposure to screens before sleeping, as light interferes with melatonin production. 12
However, during the day, exposure to sunlight will increase the production of melatonin in the evening, for better sleep.
Keep the room temperature relatively cool, between 18 and 20°C.
The body naturally lowers its temperature to help us fall asleep; a room that is too warm interferes with this process, making it harder to fall asleep and increasing nighttime awakenings. Studies have even shown that sleeping in a cooler room increases the conversion of white fat to brown fat and insulin sensitivity. 13 During the cold season, why not open the window slightly to cool the room while renewing the air, which will also have a positive impact on the quality of sleep. 14
Eat your last meal at least 2 to 3 hours before bedtime.
Digestion can increase body temperature, and metabolic activation can influence the circadian cycle, making it difficult to fall asleep. In addition, large fluctuations in blood sugar can cause nighttime awakenings, as this can be perceived as stress, which leads to the release of cortisol. Prioritize a last meal that is neither too heavy nor too rich in carbohydrates, and why not include foods rich in tryptophan, precursors of serotonin and therefore melatonin, such as legumes, nuts, or avocados. 15
Limit caffeine intake. This is because caffeine is an adenosine antagonist.
Adenosine is a residual molecule from the use of ATP, cellular energy. Throughout the day, it accumulates in the brain to slow down neuronal activity and increase drowsiness. Caffeine works by blocking adenosine receptors, preventing fatigue and altering sleep patterns the following night. However, since its half-life is 5 to 6 hours, this means that even 12 hours after consumption, a quarter of the caffeine dose is still blocking the receptors. It is therefore really important to limit the dose, but also to pay attention to the time of day at which it is consumed. 16
Practice physical activity, ideally during the day, at the latest 2 to 3 hours before bedtime.
Since physical activity increases our cells' use of ATP, it also increases the accumulation of adenosine in the brain to promote sleep. However, it should not be practiced too late in the evening for several reasons. Among other things, moderate to intense physical activity releases cortisol and adrenaline, which interferes with melatonin production. It also increases body temperature, making it more difficult to fall asleep if practiced shortly before bed.
Using essential oils can clearly improve the quality of sleep.
For example, lavender essential oil diffused without the knowledge of study participants during a sleep electroencephalogram (EEG) demonstrated better quality and greater quantity of deep slow wave sleep (NREM 3) than when it was not diffused. 17 A meta-analysis reports that massaging essential oil is even more effective than inhaling it. 18
Some natural health products may support better sleep.
There Melatonin , the sleep hormone, promotes falling asleep and reaching deep sleep stages, without any habit-forming effect. Medicinal plants, such as those found in Super powder - Dodo , are also traditionally used in herbal medicine to help improve sleep. They are also known to calm mental restlessness and reduce anxiety, which certainly can't hurt with the modern lifestyle where chronic stress is omnipresent.
As you've probably noticed, sleep is not something to be neglected. It's really time to reprogram the "sleep is for the weak" or "you'll sleep when you're dead" mentalities. Sleep is not optional, nor is it wasted time. Prioritizing rest is essential for a long and healthy life, so let's give it the importance it deserves.
Good night everyone!
References
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2. Lim MM, Xu J, Holtzman DM, Mach RH. Sleep deprivation differentially affects dopamine receptor subtypes in mouse striatum. Neuroreport. 2011 Jul 13;22(10):489-93. doi:10.1097/WNR.0b013e32834846a0. PMID: 21642879; PMCID: PMC3116438.
3. Goldstein AN, Walker MP. The role of sleep in emotional brain function. Annu Rev Clin Psychol. 2014;10:679-708. doi: 10.1146/annurev-clinpsy-032813-153716. Epub 2014 Jan 31. PMID: 24499013; PMCID: PMC4286245.
4. van Egmond LT, Meth EMS, Engström J, Ilemosoglou M, Keller JA, Vogel H, Benedict C. Effects of acute sleep loss on leptin, ghrelin, and adiponectin in adults with healthy weight and obesity: A laboratory study. Obesity (Silver Spring). 2023 Mar;31(3):635-641. doi:10.1002/oby.23616. Epub 2022 Nov 20. PMID: 36404495.
5. Bourdua-Roy, Èvelyne. “How Sleep Can Help You Stay Slim or Make You Diabetic,” Vitalité Québec. September 12, 2023. (Accessed December 30, 2024). https://vitalitequebec-magazine.com/comment-le-sommeil-peut-vous-aider-a-rester-mince-ou-a-vous-rendre-diabetique/
6. Van Cauter E, Plat L. Physiology of growth hormone secretion during sleep. J Pediatr. 1996 May;128(5 Pt 2):S32-7. doi: 10.1016/s0022-3476(96)70008-2. PMID: 8627466.
7. Stickgold R, Walker MP. Sleep-dependent memory consolidation and reconsolidation. Sleep Med. 2007 Jun;8(4):331-43. doi: 10.1016/j.sleep.2007.03.011. Epub 2007 Apr 30. PMID: 17470412; PMCID: PMC2680680.
8. Jessen NA, Munk AS, Lundgaard I, Nedergaard M. The Glymphatic System: A Beginner's Guide. Neurochem Res. 2015 Dec;40(12):2583-99. doi:10.1007/s11064-015-1581-6. Epub 2015 May 7. PMID: 25947369; PMCID: PMC4636982.
9. Foisy, Philippe-Vincent. “Let’s stop changing the clocks!”, Journal de Montréal. March 9, 2023. (Accessed February 27, 2025) https://www.journaldemontreal.com/2023/03/09/arretons-de-changer-lheure
10. Jean-Philippe Chaput, Caroline Dutil, Ryan Featherstone, Robert Ross, Lora Giangregorio, Travis J. Saunders, Ian Janssen, Veronica J. Poitras, Michelle E. Kho, Amanda Ross-White, Sarah Zankar, and Julie Carrier. 2020. Sleep timing, sleep consistency, and health in adults: a systematic review. Applied Physiology, Nutrition, and Metabolism. 45(10 (Suppl. 2)): S232-S247. https://doi.org/10.1139/apnm-2020-0032
11. Suni E, Singh A. “Stages of sleep: What happens in a sleep cycle” Sleep Foundation. December 8, 2023. (Accessed February 27, 2025). https://www.sleepfoundation.org/stages-of-sleep
12. IC Mason, D. Grimaldi, KJ Reid, CD Warlick, RG Malkani, SM Abbott, & PC Zee, Light exposure during sleep odd cardiometabolic function, Proc. Natl. Acad. Sci. USA 119 (12) e2113290119, https://doi.org/10.1073/pnas.2113290119 (2022).
13. Ellis, Mary. “'Good' brown fat stimulated by cold, study shows” Medical News Today. June 23, 2014. (Accessed February 27, 2025) https://www.medicalnewstoday.com/articles/278646
14. Xu X, Lian Z, Shen J, Cao T, Zhu J, Lin X, Qing K, Zhang W, Zhang T. Experimental study on sleep quality affected by carbon dioxide concentration. Indoor Air. 2021 Mar;31(2):440-453. doi:10.1111/ina.12748. Epub 2020 Oct 12. PMID: 32979003.
15. Pacheco D, Singh A. “Is eating before bed bad?” Sleep Foundation. April 22, 2024. (Accessed February 27, 2025. https://www.sleepfoundation.org/nutrition/is-it-bad-to-eat-before-bed
16. Carissa L Gardiner, Jonathon Weakley, Louise M Burke, Francesca Fernandez, Rich D Johnston, Josh Leota, Suzanna Russell, Gabriella Munteanu, Andrew Townshend, Shona L Halson, Dose and timing effects of caffeine on subsequent sleep: a randomized clinical crossover trial, Sleep, 2024;, zsae230, https://doi.org/10.1093/sleep/zsae230
17. Ko LW, Su CH, Yang MH, Liu SY, Su TP. A pilot study on essential oil aroma stimulation for enhancing slow-wave EEG in sleeping brain. SciRep. 2021 Jan 13;11(1):1078. doi:10.1038/s41598-020-80171-x. PMID: 33441798; PMCID: PMC7806966.
18. Kim ME, Jun JH, Hur MH. [Effects of Aromatherapy on Sleep Quality: A Systematic Review and Meta-Analysis]. J Korean Acad Nurs. 2019 Dec;49(6):655-676. Korean. doi:10.4040/jkan.2019.49.6.655. PMID: 31932562.
Maison Jacynthe disclaims all liability. All information contained on this page is not intended to replace justified allopathic treatment, nor to disregard the expertise of the medical profession. It is up to each individual to take charge of their own health, to inform themselves, and to make the necessary changes to improve their condition. Therapeutic supervision by a qualified health professional is obviously recommended.
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