Why Your Brain Needs Sleep
Getting good sleep is critical for long term brain health. There are several ways that sleep impacts your brain:
Memory: Every day, your brain is processing new experiences, skills you pick up, and people you meet. When you go to sleep at night, your brain prioritizes which of these connections to store into your memory so you can recall and remember them tomorrow and for years to come.
Toxin removal: Beta-amyloid is a sticky protein that builds up in the brain and is thought to be a leading cause of Alzheimer’s disease. As you sleep, the brain’s lymphatic system cleans out beta-amyloid and other toxins. Losing sleep for even one night can lead to increases of beta-amyloid in the brain.
Cognitive function: Sleep is critical for cognition, attention, decision-making, and higher cortical function, the type of thinking that allows you to multitask. Getting fewer than 7 hours of sleep a night can lower these necessary functions. Improving your sleep habits has also been shown to reduce your risk for cognitive decline.
Mood: Depression and insomnia have well established connections. Sleep deprivation can cause and worsen depression symptoms. Studies show that keeping a consistent sleep schedule might reduce risk for depression. There’s also a strong link between depression and dementia, making it all the more important to consistently get enough rest.
Physical health: Sleep deprivation takes a toll on the body. Getting only a few hours of sleep can lead to increases in blood pressure, heart rate, thyroid hormone, and the stress hormone cortisol. Lack of sleep is also connected to obesity and diabetes, two additional risk factors for cognitive decline.
Sleep experts recommend practicing what’s called “sleep hygiene” to help you get the sleep you need. Creating a calm environment where you sleep that is dark, quiet, and cool can help facilitate quality sleep. Avoiding electronic screens for at least one hour before bedtime also helps your brain get ready for sleep. One of the top sleep hygiene tips is to set a schedule. Waking up at the same time each day, even on weekends can help you get more sleep and protect your brain against the negative effects of sleep deprivation.
- Alzheimer’s Association. (2017). Beta-amyloid and the amyloid hypothesis. https://www.alz.org/national/documents/topicsheet_betaamyloid.pdf
- Belenky G, Wesensten NJ, Thorne DR, Thomas ML, Sing HC, Redmond DP, et al. Patterns of performance degradation and restoration during sleep restriction and subsequent recovery: a sleep dose-response study. J Sleep Res. 2003;12: 1–12.
- Buxton, O. M., & Marcelli, E. (2010). Short and long sleep are positively associated with obesity, diabetes, hypertension, and cardiovascular disease among adults in the United States. Social science & medicine, 71(5), 1027-1036.
- Byers, A. L., & Yaffe, K. (2011). Depression and risk of developing dementia. Nature Reviews Neurology, 7(6), 323–331. https://doi.org/10.1038/nrneurol.2011.60
- Drummond SP. The Effects of Total Sleep Deprivation and Recovery Sleep on Cognitive Performance and Brain Function [Internet]. 2004. doi:10.21236/ada435504
- Maquet P. The role of sleep in learning and memory. Science. 2001;294: 1048–1052.
- Miyata S, Noda A, Ozaki N, Hara Y, Minoshima M, Iwamoto K, et al. Insufficient sleep impairs driving performance and cognitive function. Neurosci Lett. 2010;469: 229–233.
- Radiological Society of North America. Short-term sleep deprivation affects heart function. In: EurekAlert! [Internet]. 2 Dec 2016 [cited 28 Feb 2019]. Available: https://www.eurekalert.org/pub_releases/2016-12/rson-ssd111816.php
- Shokri-Kojori E, et al. (2018). β-Amyloid accumulation in the human brain after one night of sleep deprivation. Proceedings of the National Academy of Sciences. http://www.pnas.org/content/early/2018/03/29/1721694115.full
- Sleep Foundation. (2020). Depression and sleep. Sleepfoundation.Org.