If even one of those conditions is not met, then the individual is probably not obtaining sufficient sleep. The answer, though, may not be as clear when we look at different populations.
In the industrial world, short sleep duration — the amount of time one is asleep — has been linked with multiple adverse health outcomes, including type II diabetes, weight gain, mood disorders, learning disabilities, decreased immune function to fight off illness, impaired performance and alertness, motor vehicle accidents and industrial accidents.
How much sleep does an individual “need” to be healthy? The answer is, we don’t yet know! The current belief by sleep doctors is that an individual who meets all of the following criteria is likely getting “enough” sleep:
(i) sleeps the same amount on work days and non-work days,
(ii) awakens without an alarm clock,
(iii) does not use caffeine or other stimulants to remain awake or substances to fall asleep,
(iv) does not fall asleep within five minutes or in other non-stimulating conditions (e.g., when a passenger in a car)
(v) is healthy.
If even one of those conditions is not met, then the individual is probably not obtaining sufficient sleep. The answer, though, may not be as clear when we look at different populations.
In the industrial world, short sleep duration — the amount of time one is asleep — has been linked with multiple adverse health outcomes, including type II diabetes, weight gain, mood disorders, learning disabilities, decreased immune function to fight off illness, impaired performance and alertness, motor vehicle accidents and industrial accidents.
Two recent published reports on sleep duration in “hunter-gatherer” societies, or other communities living without electricity, have documented shorter sleep duration than that recommended by sleep experts in the industrial world. It is assumed, but not proven, that the health of the people studied is not negatively affected by this shorter sleep.
Other reports have found longer sleep durations in societies without electricity, which align with recommendations by sleep experts.
The type of society that an individual lives in is only one factor that affects the amount of sleep an individual gets. Some (but not all) factors include:
- The “drive” for sleep, which increases the longer you are awake and decreases during sleep;
- The body’s internal sleep/wake clock, which biologically promotes both wake and sleep dependent on the time of day;
- Age;
- Environmental conditions such as room temperature.
In industrial societies, sleep is often restricted by choice (e.g., to be with others, watch TV, use the internet) or for work-related reasons (e.g., if you must work multiple jobs or if your job requires long hours).
Sleep research that we have conducted at Brigham and Women’s Hospital in Boston has shown that healthy individuals sleep for far shorter periods of time when they are living at home than when they are in a controlled setting where they must remain in bed for longer than they usually do at home.
“If sleep does not serve an absolutely vital function, then it is the biggest mistake the evolutionary process has ever made,” wrote Allan Rechtschaffen (a leading sleep researcher).
During sleep, creatures are not eating, procreating or capable of defending themselves and yet its presence is ubiquitous (existing in organism as diverse as flies and humans), obligatory (animals die if deprived of sleep), and complex (comprising both NREM and REM sleep stages).
And while Rechtschaffen’s quote makes a lot of sense, we still don’t know what the function(s) of sleep are, although we can infer it based on what we know about the dangers of insufficient sleep. It could be possible, for example, to obtain enough sleep to meet immune function “needs” but not enough for metabolic “needs.”
Therefore, it is possible that you might feel “rested” after sleeping six hours, but your metabolic recovery is not yet complete. The science to answer these questions has not yet been done.
Unlike treatments for many medical conditions, sleep does not require out-of-pocket or insurance payments, does not require training or special equipment, does not require doctor/nurse appointments or prescriptions, can be done at home or elsewhere and therefore has no travel requirements, has no side effects and has multiple health (including mental health) benefits.
Health care professionals, therefore, strongly encourage individuals to sleep more. If you are tired after being in bed for 8 hours and/or your bed-partner says you snore or stop breathing during sleep and/or you have questions about the quality or quantity of your sleep, please consult a health professional.
Resources:
• National Sleep Foundation
• NIH studies
• Center for Disease Control (CDC)
• Harvard Medical School “Healthy Sleep”
References:
1. Mills SL, Tian LM, Hoshi H, Whitaker CM, Massey SC: Three distinct blue-green color pathways in a mammalian retina. The Journal of neuroscience : the official journal of the Society for Neuroscience 2014, 34(5):1760-1768.
2. Yetish G, Kaplan H, Gurven M, Wood B, Pontzer H, Manger PR, Wilson C, McGregor R, Siegel JM: Natural Sleep and Its Seasonal Variations in Three Pre-industrial Societies. Current biology : CB 2015.
3. Czeisler CA: Duration, timing and quality of sleep are each vital for health, performance and safety. Sleep Health 2015, 1(1):5-8.
4. Knutson KL: Sleep duration, quality, and timing and their associations with age in a community without electricity in Haiti. American journal of human biology : the official journal of the Human Biology Council 2014, 26(1):80-86.
5. de la Iglesia HO, Fernandez-Duque E, Golombek DA, Lanza N, Duffy JF, Czeisler CA, Valeggia CR: Access to Electric Light Is Associated with Shorter Sleep Duration in a Traditionally Hunter-Gatherer Community. JBiol Rhythms 2015.
6. Moreno CR, Vasconcelos S, Marqueze EC, Lowden A, Middleton B, Fischer FM, Louzada FM, Skene DJ: Sleep patterns in Amazon rubber tappers with and without electric light at home. Sci Rep 2015, 5:14074.
7. Piosczyk H, Landmann N, Holz J, Feige B, Riemann D, Nissen C, Voderholzer U: Prolonged sleep under Stone Age conditions. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine 2014, 10(7):719-722.
8. Peixoto CA, da Silva AG, Carskadon MA, Louzada FM: Adolescents living in homes without electric lighting have earlier sleep times. Behavioral Sleep Medicine 2009, 7(2):73-80.
9. Wright KP, Jr., McHill AW, Birks BR, Griffin BR, Rusterholz T, Chinoy ED: Entrainment of the human circadian clock to the natural light-dark cycle. Current Biology 2013, 23(16):1554-1558.
10. Chang AM, Aeschbach D, Duffy JF, Czeisler CA: Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci 2015, 112(4):1232-1237.
11. Bianchi MT, Thomas RJ, Ellenbogen JM: Hypnotics and mortality risk. Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine 2012, 8(4):351-352.
12. Klerman EB, Dijk DJ: Interindividual variation in sleep duration and its association with sleep debt in young adults. Sleep 2005, 28:1253-1259.
13. Klerman EB, Dijk DJ: Age-related reduction in the maximal capacity for sleep – implications for insomnia. Current Biology 2008, 18(15):1118-1123.
14. Johns MW: A new method for measuring daytime sleepiness: The Epworth Sleepiness Scale. Sleep 1991, 14(6):540-545.
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