Substances
Drugs, alcohol, and other psychoactive substances have significant effects on sleep. Their use warrant careful consideration on polyphasic sleep schedules.
Caffeine
Caffeine is the most widespread psychoactive drug in the world[1] and is contained in large quantities in coffee and, in lower concentration, in other beverages that are regularly consumed to temporally ward of drowsiness or increase mental performance. Caffeine relieves drowsiness by blocking adenosine receptors in the brain [2], due to a similar chemical structure as adenosine[3], that are a part of the sleep regulation mechanism.
Caffeine is shown to reduce time spent in SWS and REM[4][5] in rats.
There are large genetically based differences in caffeine clearance time in the body[6], which might account for anecdotal accounts of varying sensitivity and prolonged effects of caffeine after ingestion. However, having a low sensitivity and still being able to fall asleep does not mean that the resulting sleep is unaffected.
Caffeine concentration in beverages
Average caffeine content in beverages[7][8][9][10][11]
| Product | Serving size | Caffeine(mg/serving) | Caffeine(mg/L) |
|---|---|---|---|
| Percolated coffee | 207 mL (7.0 US fl oz) | 80–135 | 386–652 |
| Drip coffee | 207 mL (7.0 US fl oz) | 115–175 | 555–845 |
| Coffee, decaffeinated | 207 mL (7.0 US fl oz) | 5–15 | 24–72 |
| Green tea | 236 mL (8.0 US fl oz) | 25 | 106 |
| Black tea | 236 mL (8.0 US fl oz) | 42 | 178 |
| Coca-Cola | 355 mL (12.0 US fl oz) | 34 | 96 |
| Mountain Dew | 355 mL (12.0 US fl oz) | 54 | 154 |
| Pepsi Zero Sugar | 355 mL (12.0 US fl oz) | 69 | 194 |
| Red Bull | 250 mL (8.5 US fl oz) | 80 | 320 |
Note: Caffeine content in tea can vary significantly based on leaf type and steeping time.
Detailed info on Green tea and Black tea.
Caffeine use with polyphasic sleep
Because of the potential for it to disrupt sleep and its long half-life, the use of caffeine is discouraged on polyphasic schedules. In particular, it reduces the amount of SWS and REM sleep, which detrimentally affects the quality of naps and cores. On schedules with short wake gaps (other than Segmented), there is not enough time for caffeine to be eliminated from the system by the time the next sleep starts, so it inevitably causes disruption. The negative effects of caffeine on sleep significantly outlasts both the perceptible cognitive boost and the crash, affecting the next sleep block in a subtle but negative way.
Alcohol
Alcohol can increase drowsiness, but it also reduces sleep quality by temporarily increasing the need for SWS and generally disrupting sleep structure. The effect is more pronounced in polyphasic sleep schedules, because the reduced core sleep duration meant there is less time to recover from the disruption in the later hours.
During adaptation, using alcohol especially close to sleep is likely to negatively affect the adaptation process by disrupting sleep architecture. It may also cause oversleeps due to a sudden increase in drowsiness, setting back adaptation that way.
References
- ↑ Burchfield G (1997). Hopes M (ed.). "What's your poison: caffeine". Australian Broadcasting Corporation. Archived from the original on 26 July 2009. Retrieved 15 January 2014.
- ↑ Bjorness TE, Greene RW (September 2009). "Adenosine and Sleep". Current Neuropharmacology. 7 (3): 238–245. doi:10.2174/157015909789152182. PMC 2769007. PMID 20190965.
- ↑ "The structure of caffeine is very similar to adenosine, which allows it to bind to (all) the A1, A2a, A2b, and A3 ARs." in "Progress in Neuro-Psychopharmacology and Biological Psychiatry" by JuliusSchuster, Ellen S.Mitchell
- ↑ Jang H, Jung J, Jang I, Jang K, Kim S, Ha J, Lee M (2012). "L-theanine partially counteracts caffeine-induced sleep disturbances in rats". Pharmocology, biochemistry, and behavior. 101 (2). doi:10.1016/j.pbb.2012.01.011.
- ↑ Radulovacki M, Virus RM, Djuricic-Nedelson M, Green RD (February 1984). "Adenosine analogs and sleep in rats". Journal of Pharmacology and Experimental Therapeutics. 228 (2): 268–274.
- ↑ "CYP1A2 gene polymorphism has been shown to alter the expression or activity of the CYP1A2 enzyme (Rasmussen et al., 2002), which subsequently results in a large individual variability of caffeine clearance." in "Progress in Neuro-Psychopharmacology and Biological Psychiatry" by JuliusSchuster, Ellen S.Mitchell
- ↑ "Caffeine Content of Food and Drugs". Nutrition Action Health Newsletter. Center for Science in the Public Interest. 1996. Archived from the original on 14 June 2007. Retrieved 3 August 2009.
- ↑ "Caffeine Content of Beverages, Foods, & Medications". The Vaults of Erowid. 7 July 2006. Retrieved 3 August 2009.
- ↑ "Caffeine Content of Drinks". Caffeine Informer. Retrieved 8 December 2013.
- ↑ Chin JM, Merves ML, Goldberger BA, Sampson-Cone A, Cone EJ (October 2008). "Caffeine content of brewed teas". Journal of Analytical Toxicology. 32 (8): 702–704. doi:10.1093/jat/32.8.702. PMID 19007524.
- ↑ Richardson B (2009). "Too Easy to be True. De-bunking the At-Home Decaffeination Myth". Elmwood Inn. Archived from the original on 27 December 2011. Retrieved 12 January 2012.
See also
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