Sweet, sweet sleep—nature’s elixir. All too often, though, good sleep is elusive. We stay up too late, get up too early and wake up in the middle of the night thinking, planning, worrying. Sometimes just getting to sleep is a monumental task. How do we make this easier?
As I mentioned in my October 5 post, our bodies are governed by nature’s rhythms. Getting in sync with these rhythms, especially the daily light/dark cycle, ensures that our hormonal system can function naturally. One of the big players in this cycle is the hormone melatonin. It naturally begins to rise after the sun sets and signals to our body that it’s nighttime. Concentrations of melatonin peak in the middle of the night and then fall. During daylight hours they reach their lowest concentrations and then rise again in the evening. As concentrations rise, we get sleepy. (1,2,3,4,5)
All good, right? Except that light has a major impact on melatonin levels and research is showing that artificial light interferes with melatonin production and alters the programing of our biological clock making it hard to fall asleep and to sleep properly. One 2011 study showed that artificial light exposure between dusk and bedtime reduced melatonin levels by 71.4%. Blue light, emitted by LED lights and electronic screens, appears to have the strongest effect. Another independent study the same year found that 5 hours of exposure to this type of light in the evening substantially suppressed the rise in melatonin and reduced sleepiness. This means that exposure to this LED-based blue light has a big impact on our biological clock and all those systems regulated by it. (3,4,5,6,7,8)
So what can you do about this? Don’t worry, you don’t have to live without artificial light in the evening.
Here are a few things that can help you get in sync with the light/dark cycle as best you can: (8, 9)
- Set boundaries around lighting in the evening, especially bright blue light.
- Mimic nature’s natural rhythm for melatonin by turning off all screens at 8 pm, and dim the overhead lights a bit. Incandescent bulbs emit more red-wave light and don’t have as strong of effect.
- Go to bed by 10 pm as this is about when melatonin levels are reaching a crescendo.
- Establish a regular time to go to bed and to get up—our bodies love regularity (even though our minds don’t seem to).
- If you need to, use ear plugs and eye patches to enhance your ability to withdraw into sleep.
- Try to eat at least two hours, preferably three, before bedtime so that your digestive process is well on its way before lying down.
- Avoid caffeine in the afternoon and evening.
- Minimize alcohol intake—it makes us sleepy but results in shorter sleep duration and poorer quality of sleep—better to take a warm bath with Epsom salts instead.
And finally, make sure that you are out in natural daylight every day so that your biological clock can tune itself into the genuine light/dark cycle.
Next time: we’ll have a look at that Stanford study that dissed organic foods—what’s the story there?
- Dijk D-J, Duffy JF, Silva EJ, Shanahan TL, Boivin DB, et al. (2012) Amplitude Reduction and Phase Shifts of Melatonin, Cortisol and Other Circadian Rhythms after a Gradual Advance of Sleep and Light Exposure in Humans. PLoS ONE 7(2): e30037. doi:10.1371/journal.pone.0030037.
- Beil, L. (July 4, 2011) In Eyes, A Clock Calibrated by Light. New York Times. NY. Available at: http://www.nytimes.com/2011/07/05/health/05light.html?pagewanted=all&_r=1&
- Raloff, J. (October 17, 1998) Does Light Have a Dark Side? Science News. Available at: http://www.sciencenews.org/sn_arc98/10_17_98/19981017fob.asp
- Gooley, J.J., Chamberlain, K., Smith, K.A., Khalsa, S.B.S., Rajaratnam, S.M.W., Reen, E.V., Zeitzer, J.M., Czeisler, C.A., and Lockley, S.W. (2011) Exposure to Room Light Before Bedtime Suppresses Melatonin Onset and Shortens Melatonin Duration in Humans. Journal of Clinical Endocrinology and Metabolism. 96: E463-472
- Figueiro, M.G. and Rea, M.S. (May 2011) Sleep Opportunities and Periodic Light Exposures: Impact on Biomarkers, Performance and Sleepiness. Lighting Research and Technology. 43: 349-369 Available at: http://lrt.sagepub.com/content/43/3/349
- Salgado-Delgado, R., Tapia Osorio, A., Saderi, N. and Escobar, C. (2011) Disruption of Circadian Rhythms: A Crucial Factor in the Etiology of Depression. Depression Research and Treatment. Hindawi Publishing Corporation. 839743. Epub 2011 Aug 8
- Christian Cajochen, S.F., Anders, D., Spati, J., Bues, M., Pross, A., Mager, R., Wirz-Justice, A. and Stefaniz, O. (2011) Evening Exposure to a Light-Emitting Diodes (LED)-Backlit Computer Screen Affects Circadian Physiology and Cognitive Performance. Journal of Applied Physiology. 10:1432-1438
- Harvard University (October 16, 2012) Blue Light Has a Dark Side. Harvard Health Letter. Source: https://www.health.harvard.edu/newsletters/Harvard_Health_Letter/2012/May/blue-light-hasa-dark-side/
- Happy Healthy Long Life (August 10, 2012) My Simple Sweet Sleep Challenge…. Available at: http://www.happyhealthylonglife.com/happy_healthy_long_life/sleep/