8 Reasons why sleep is important
A good night's sleep is essential for your health and wellbeing. Sleep is restorative. It allows your body to relax and recover. Getting the right amount of good quality sleep is important and has many health benefits, such as reducing your risk of heart disease, improving your concentration, boosting your mood, supporting your emotional wellbeing, and improving your athletic performance.
To help you stay healthy, adults 18 years of age and over should get 7 or more hours of sleep each night on a regular basis.
If you don’t get enough sleep, you risk becoming sleep-deprived, which can harm your physical and mental health. Lack of sleep also puts you at greater risk of injuries and accidents and can affect your general health and make you more susceptible to developing certain serious medical conditions.
Here are 8 reasons why sleep is important.
1. Sleep helps you maintain a healthy weight
Lack of sleep has been linked to weight gain and obesity. Not only do your energy needs increase as you get short on sleep, so does your desire for food.
Studies have shown that short sleep duration affects metabolic hormones such as leptin and ghrelin. Leptin is known as the satiety hormone. It suppresses appetite or feelings of hunger and helps the body control energy expenditure. Ghrelin, on the other hand, is the ‘hunger hormone’ because it stimulates your appetite.
Lack of sleep has been shown to reduce leptin levels and increase levels of ghrelin. This is likely to increase your appetite and have you reaching for unhealthy foods high in carbohydrates, fat, and sugar for a quick energy boost. An increase in calories can lead to weight gain, obesity, and potentially even diabetes.
Regularly getting the recommended amount of sleep each day can help you maintain a healthy weight.
2. Sleep improves your concentration
Sleep is important for healthy brain function. Poor sleep affects cognitive abilities such as your ability to concentrate, be productive, learn, and process memories.
A lack of sleep can lead to fatigue and impairment that is similar or worse than that observed in people with a blood alcohol concentration of 0.10 percent. At that level of drunkenness, a person would struggle to keep their car in their own lane and would have difficulty braking when required.
A lack of sleep can also contribute to people making mistakes. A study following medical interns found that interns who worked a traditional work schedule (with extended 24hr or more shifts every other shift) made 36 percent more serious medical mistakes than interns who worked a schedule that reduced the total number of hours worked per week and eliminated the extended shifts altogether.
A good night’s sleep is crucial for your memory, allowing your brain to form memories from information gathered before going to sleep and to prepare for new memories that will be made when you wake up. This is important for performing tasks and for learning.
Getting the right amount of good quality sleep improves cognitive function. Allowing better decision making, problem-solving, creative thinking, focus, attention, concentration, and language processing.
3. Sleep can improve your athletic performance
Sleep has a significant impact on physical development. Sleep is an integral part of the recovery process between bouts of physical activity. It allows your body to rest and your cells and tissues to repair.
There is also growing evidence that longer sleep duration has a positive influence on athletic performance. Getting plenty of sleep can improve reaction time, accuracy, and endurance performance. Studies looking at team sports have also associated getting more sleep with an increased chance of competitive success. Good quality sleep may also reduce the risk of injury, illness, and stress.
A good night’s sleep has an important role in improving athletic performance.
4. Sleep may reduce your risk of heart disease and stroke
The duration and quality of your sleep can have a major impact on your heart health. Your blood pressure and heart rate reduce while you’re asleep, allowing your heart and blood vessels to rest. Poor or interrupted sleep can cause your blood pressure to stay higher for a longer period. High blood pressure is one of the major risks for heart disease and stroke. Poor sleep has also been linked to an increase in inflammation, which is common in people with heart disease.
One study looking at the duration of sleep and risk of heart attack found that people who slept less than 6 hours a night had a 20 percent higher risk of heart attack compared with those people who slept 6-9 hours a night. Sleeping more than 9 hours per night was also associated with a 34 percent higher risk of a heart attack.
People who suffer from sleep apnea, a chronic sleep condition, are at a higher risk of developing heart disease and high blood pressure, as well as obesity. Sleep apnea causes short pauses in breathing during sleep, which results in poor quality sleep and sudden drops in oxygen levels.
Getting a good night’s sleep can help reduce your risk of heart disease and stroke.
5. Sleep may reduce your risk of type 2 diabetes
Not getting the right amount of good quality sleep can put you at greater risk of developing type 2 diabetes.
Researchers who looked at the results of 10 studies found that sleeping less than 5-6 hours a night or more than 8-9 hours a night puts people at great risk of developing type 2 diabetes. People who struggled to go to sleep or struggled to stay asleep were also at greater risk of developing the disease.
Lack of sleep is thought to impair glucose metabolism and increase insulin levels. Glucose (blood sugar) is formed when your body breaks down the carbohydrates in your food. It is used to fuel your body. In people with diabetes, however, glucose levels get too high because of an issue with insulin, the hormone that keeps glucose levels in balance.
One week of restricted sleep of 4 hours per night resulted in changes in glucose metabolism that are typically found in people who go on to develop type 2 diabetes, according to the results of a small study conducted in 11 healthy young men.
Another small study found that men who slept less than 6.5 hours at night had a 40 percent lower sensitivity to insulin compared with men who slept 7.5-8.5 hours per night. Glucose tolerance was similar between the two groups, indicating that larger amounts of insulin were necessary to achieve normal glucose tolerance in men who were partially sleep-deprived.
A separate study also found that glucose metabolism was changed in people who were subjected to five nights’ sleep restriction. However, two nights of normal sleep helped to restore things to normal, indicating that getting a good night’s sleep can help to reduce your risk of developing type 2 diabetes.
6. Sleep is important for your mental health
Sleep deficiency affects mental health and has been associated with depression, suicide, and risk-taking behavior.
Sleep plays an important role in regulating your emotions. A bad night’s sleep can affect your mood and emotional responses and can leave you feeling irritable, unmotivated, distracted, and generally unhappy during the day.
Sleep conditions such as insomnia and sleep apnea can also exacerbate existing mental health conditions, causing the symptoms to become more severe. Insomnia and sleep apnea may also play a role in the development of certain mental disorders. The reverse is also true - mental disorders such as depression and anxiety can also affect your ability to get a good night’s sleep.
Taking steps to make sure you get the recommended amount of sleep and improving your sleep quality can have a positive effect on existing mental health conditions and may also help to prevent them from developing.
7. Sleep helps improve your immune function
Sleep is important for keeping your immune system healthy. Your immune system is responsible for protecting your body from foreign or harmful substances. Research has shown a strong relationship between quality of sleep and immune defense.
Poor sleep can make it harder for your immune system to deal with infection and inflammation. A study has shown that people who slept less than seven hours a night were nearly three times more likely to catch a common cold compared with people who slept eight hours or more.
Getting the recommended amount of sleep regularly can help improve the function of your immune system.
8. Sleep may help reduce your risk of dementia
Getting enough sleep in middle age may be an important factor in reducing your risk of developing dementia later in life. A lack of sleep in middle age may increase your risk of dementia, according to the results of research.
People who slept 6 hours or less per night during their 50s and 60s were more likely to develop dementia later in life compared with people who got 7 hours of sleep per night, according to data gathered from 7959 participants in the Whitehall II study. The participants getting less sleep at night were 30 percent more likely to receive a dementia diagnosis. A total of 521 participants were diagnosed with dementia (at an average age of 77 years old) during the course of the study.
Results from the US National Health and Aging Trends Study (NHATS) also reported that short sleep duration (less than 5 hours) and taking a longer time (more than 30 minutes) to fall asleep were strong predictors of incident dementia. The study was conducted in Medicare beneficiaries aged 65 years and older.
Taking the time to get enough sleep and working to resolve any problems you have with sleep may help prevent dementia from developing in the future.
Sleep is an important part of a daily routine. Getting the recommended seven to eight hours of uninterrupted sleep is good for your physical and mental health. It can help regulate your emotions, improve cognitive functions, improve mental health, support your immune system and help prevent certain serious medical conditions. A good sleep pattern, especially in middle age, may also reduce your risk of developing dementia later on in life.
Improving the duration and quality of your sleep can make you feel better and able to function properly. Diet, exercise, and other natural remedies may also help you achieve better sleep habits.
Consult a healthcare professional if you are having trouble sleeping or are feeling tired during the day.
- Watson NF, Badr MS, Belenky G, et al. Recommended Amount of Sleep for a Healthy Adult: A Joint Consensus Statement of the American Academy of Sleep Medicine and Sleep Research Society. Sleep. 2015;38(6):843-844. Published 2015 Jun 1. doi:10.5665/sleep.4716. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4434546/
- National Health Service (NHS). Why lack of sleep is bad for your health. May 30, 2018. Available at: https://www.nhs.uk/live-well/sleep-and-tiredness/why-lack-of-sleep-is-bad-for-your-health/. [Accessed 27 July, 2021].
- Markwald RR, Melanson EL, Smith MR, et al. Impact of insufficient sleep on total daily energy expenditure, food intake, and weight gain. Proc Natl Acad Sci U S A. 2013;110(14):5695-5700. doi:10.1073/pnas.1216951110.
- Taheri S, Lin L, Austin D, Young T, Mignot E. Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Med. 2004;1(3):e62. doi:10.1371/journal.pmed.0010062.
- Landrigan CP, Rothschild JM, Cronin JW, et al. Effect of reducing interns' work hours on serious medical errors in intensive care units. N Engl J Med. 2004;351(18):1838-1848. doi:10.1056/NEJMoa041406.
- Dawson, D., Reid, K. Fatigue, alcohol and performance impairment. Nature 388, 235 (1997). doi.org/10.1038/40775.
- Alhola P, Polo-Kantola P. Sleep deprivation: Impact on cognitive performance. Neuropsychiatr Dis Treat. 2007;3(5):553-567. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2656292/.
- Diekelmann Susanne. Sleep for cognitive enhancement. Frontiers in Systems Neuroscience. Vol, 8. 2014. Pgs 46. doi:10.3389/fnsys.2014.00046.
- Watson, Andrew M. MD. MS Sleep and Athletic Performance, Current Sports Medicine Reports: 11/12 2017 - Volume 16 - Issue 6 - p 413-418 doi: 10.1249/JSR.0000000000000418.
- Charest J, Grandner MA. Sleep and Athletic Performance: Impacts on Physical Performance, Mental Performance, Injury Risk and Recovery, and Mental Health. Sleep Med Clin. 2020;15(1):41-57. doi:10.1016/j.jsmc.2019.11.005.
- Daghlas I, Dashti HS, Lane J, et al. Sleep Duration and Myocardial Infarction. J Am Coll Cardiol. 2019;74(10):1304-1314. doi:10.1016/j.jacc.2019.07.022.
- Centers for Disease Control and Prevention (CDC). High Blood Pressure. How Does Sleep Affect Your Heart Health? Reviewed 4 January 4, 2021. Available at: https://www.cdc.gov/bloodpressure/sleep.htm. [Accessed 27 July, 2021].
- Heart Foundation NZ. How does sleep affect your heart? 5 April, 2019. Available at: https://www.heartfoundation.org.nz/about-us/news/blogs/how-does-sleep-affect-your-heart. [Accessed 27 July, 2021].
- van Leeuwen WM, Hublin C, Sallinen M, Härmä M, Hirvonen A, Porkka-Heiskanen T. Prolonged sleep restriction affects glucose metabolism in healthy young men. Int J Endocrinol. 2010;2010:108641. doi:10.1155/2010/108641.
- Knutson KL. Impact of sleep and sleep loss on glucose homeostasis and appetite regulation. Sleep Med Clin. 2007;2(2):187-197. doi:10.1016/j.jsmc.2007.03.004.
- Cappuccio FP, D'Elia L, Strazzullo P, Miller MA. Quantity and quality of sleep and incidence of type 2 diabetes: a systematic review and meta-analysis. Diabetes Care. 2010;33(2):414-420. doi:10.2337/dc09-1124.
- Riemann D, Berger M, Voderholzer U. Sleep and depression--results from psychobiological studies: an overview. Biol Psychol. 2001;57(1-3):67-103. doi:10.1016/s0301-0511(01)00090-4.
- Deliens G, Gilson M, Peigneux P. Sleep and the processing of emotions. Exp Brain Res. 2014;232(5):1403-1414. doi:10.1007/s00221-014-3832-1.
- Grandner, M.A. and Malhotra, A. (2017) Connecting insomnia, sleep apnoea and depression. Respirology, 22: 1249– 1250. doi: 10.1111/resp.13090.
- Vandekerckhove M, Wang YL. Emotion, emotion regulation and sleep: An intimate relationship. AIMS Neurosci. 2017;5(1):1-17. Published 2017 Dec 1. doi:10.3934/Neuroscience.2018.1.1.
- Health Navigator NZ. How does sleep affect mental wellbeing?. Reviewed 27 April, 2021. Available at: https://www.healthnavigator.org.nz/healthy-living/s/sleep-and-mental-health/. [Accessed 27 July, 2021].
- Cohen S, Doyle WJ, Alper CM, Janicki-Deverts D, Turner RB. Sleep habits and susceptibility to the common cold. Arch Intern Med. 2009;169(1):62-67. doi:10.1001/archinternmed.2008.505.
- Mullington JM, Simpson NS, Meier-Ewert HK, Haack M. Sleep loss and inflammation. Best Pract Res Clin Endocrinol Metab. 2010;24(5):775-784. doi:10.1016/j.beem.2010.08.014.
- Besedovsky L, Lange T, Born J. Sleep and immune function. Pflugers Arch. 2012;463(1):121-137. doi:10.1007/s00424-011-1044-0.
- Robbins R, Quan SF, Weaver MD, Bormes G, Barger LK, Czeisler CA. Examining sleep deficiency and disturbance and their risk for incident dementia and all-cause mortality in older adults across 5 years in the United States. Aging (Albany NY). 2021;13(3):3254-3268. doi:10.18632/aging.202591.
- Sabia S, Fayosse A, Dumurgier J, et al. Association of sleep duration in middle and old age with incidence of dementia. Nat Commun. 2021;12(1):2289. Published 2021 Apr 20. doi:10.1038/s41467-021-22354-2.