Melatonin
Melatonin is a hormone produced by the pineal gland in the brain. It’s secreted into the bloodstream in accordance with our circadian or daily rhythm and levels are regulated by light and dark cycles. During darkness, melatonin levels are naturally high, helping us to fall asleep and stay asleep. They peak between two and four o’clock in the morning and gradually taper off as night turns into day, helping us to wake up.
Melatonin isn’t only important for sleep; it’s essential for good health. Melatonin has powerful antioxidant and anti-inflammatory actions in the body and it can increase the effectiveness of natural killer cells, our body’s best defense against disease-causing microbes and cell mutations. Melatonin plays an important role in protecting us against cancer, improving our immunity, maintaining a healthy digestive tract, controlling other hormones like estrogen and testosterone, and regulating blood pressure, blood sugar, and body weight.
Cortisol
Cortisol is a hormone produced by the adrenal glands (a pair of organs that sit on top of the kidneys) and it too is secreted into the blood stream in accordance with our circadian rhythm. Cortisol production is stimulated by light and levels are naturally highest during the day. Cortisol levels are lowest at night, so we can sleep, and they gradually rise during the early morning hours as our bodies prepare to wake up.
Cortisol is also secreted in response to stress. It's a survival mechanism that prepares the body for "fight or flight" action by raising alertness, increasing heart rate and blood pressure, and boosting levels of blood sugar and insulin. In order to divert energy where we need it most, cortisol shuts down processes that aren't immediately essential like digesting food, building bones, and putting immune cells on alert for bacteria, viruses, and cancer cells.
When we're continuously exposed to stress, cortisol levels can remain elevated for long periods of time. Chronic high levels of cortisol don’t only interfere with sleep; they promote a state of chronic inflammation in the body and increase the risk of illnesses like cardiovascular disease, osteoporosis, digestive problems, diabetes, Alzheimer's disease, and cancer.
Light at Night
Our bodies contain proteins called cryptochromes that can detect light's blue spectrum. They are highly active in our eyes but they also exist in our skin. When any part of our skin is exposed to light (even the back of the knee, in one study) melatonin production is suppressed. Our brain gets the message that it’s time to be awake, so cortisol levels remain elevated. Too much cortisol and not enough melatonin can cause problems falling asleep and staying asleep.
Electromagnetic Radiation
Like light, electromagnetic radiation (EMR) can interfere with sleep by shutting down the production of melatonin and altering cortisol secretion. Studies show that exposure to even "commonly occurring low frequency electromagnetic fields" can significantly reduce the production of melatonin. Some studies link EMR exposure to high cortisol levels and symptoms like insomnia, while other studies link EMR exposure to low levels of cortisol and symptoms like fatigue and daytime sleepiness.
Better Sleep
A healthy balance of melatonin and cortisol are essential for a healthy circadian rhythm. If you have trouble falling asleep or staying asleep, follow these seven tips to reduce your nighttime exposure to hormone-disrupting light and radiation.
#1 After dark, keep your lights as dim as possible and choose your light bulbs carefully.
Studies show that exposure to dim light before bed has much less impact on melatonin levels than regular room light, which can shorten melatonin secretion by 90 minutes in 99 percent of people. Compact fluorescent lamps (CFLs), which use mercury vapor to produce invisible ultraviolet (UV) radiation, emit EMR in the form of radio frequency radiation (RFR). LED (light-emitting diode) bulbs are a good alternative because they do not contain mercury and do not emit RFR.
#2 Avoid watching TV and using other electronics after 9 or 10 p.m.
If you must use electronic devices late at night, keep them as far away from your head as possible and wear glasses with amber, rose, or orange lenses to block blue light. Research has shown that wearing amber-colored glasses before bed can normalize melatonin levels and one study found that it also reduced the risk of cancer, particularly cancers of the breast, ovaries, and prostate.
#3 If you have a wireless router in your home, keep it as far away from your bedroom as possible.
Place wireless routers in an area where you spend the least amount of time, far from pregnant women, babies and children, and ideally at least 600 feet away from areas where you sleep and pass extended periods of time.
#4 Remove as many electronic devices from your bedroom as you can.
This includes televisions, cable boxes, video games, DVD players, DVRs and other recording devices, stereos, radios, sound systems, personal music players and docking stations, remote controls, computers, monitors, laptops, tablets, e-book readers, printers, fax machines, cordless phones, cell phones, chargers, digital photo frames, baby monitors, digital and analog clocks, etc. Also avoid lights with dimmer switches because they use electronic transformers that generate EMR.
Ideally, you'll only need lamps with dim light and a battery-powered alarm clock that doesn't glow in the dark. If you must use a clock that emits light, pick one that glows red instead of blue. If you can't live without a phone in your bedroom, use a corded land line instead of a cellular or cordless phone.
#5 Sleep in complete darkness.
Wearing an eye mask isn't enough. Get black-out curtains if any artificial light shines through your windows at night.
#6 If you have to get up in the middle of the night, try to avoid turning on the light.
If need be, consider using night lights that block blue light.
#7 Eat foods high in caffeic acid, a compound shown to protect against the effects of electromagnetic radiation.
The best sources of caffeic acid are cruciferous vegetables, citrus fruits, apples, and pears. Caffeic acid is also found in coffee, but in people who are sensitive, any amount of caffeine can disrupt sleep so it should be strictly avoided.
References:
Alpert M. et al. 2009. Nighttime use of special spectacles or light bulbs that block blue light may reduce the risk of cancer. Medical Hypotheses 73(3):324-5.
Akerstedt T. et al. 1999. A 50-Hz electromagnetic field impairs sleep. Journal of Sleep Research 8(1):77-81.
Barrenetxe J. et al. 2004. Physiological and metabolic functions of melatonin. Journal of Physiology and Biochemistry 60(1):61-72.
Burch J.B. et al. 1998. Nocturnal excretion of a urinary melatonin metabolite among electric utility workers. Scandinavian Journal of Work, Environment, and Health 24(3):183-9.
Gooley J.J. 2011. Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humans. Journal of Clinical Endocrinology and Metabolism 96(3):E463-72.
Havas M. 2008. Health Concerns associated with Energy Efficient Lighting and their Electromagnetic Emissions. Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR), Request for an opinion on “Light Sensitivity.” Available at http://www.electricalpollution.com/documents/08_Havas_CFL_SCENIHR.pdf (accessed 9 June 2012).
Mortazavi S.M. et al. 2012. Occupational exposure of dentists to electromagnetic fields produced by magnetostrictive cavitrons alters the serum cortisol level. Journal of Natural Science, Biology, and Medicine 3(1):60-4.
Oktem F. et al. 2005. Oxidative damage in the kidney induced by 900-MHz-emitted mobile phone: protection by melatonin. Archives of Medical Research 36(4):350-5.
Omura Y. et al. 1993. Non-invasive evaluation of the effects of opening & closing of eyes, and of exposure to a minute light beam, as well as to electrical or magnetic field on the melatonin, serotonin, & other neuro-transmitters of human pineal gland representation areas & the heart. Acupuncture and Electrotherapeutics Research 18(2):125-51.
Ozguner F. et al. 2005. Mobile phone-induced myocardial oxidative stress: protection by a novel antioxidant agent caffeic acid phenethyl ester. Toxicology and Industrial Health 21(9):223-30.
Rosales-Corral S.A. et al. 2012. Alzheimer's disease: pathological mechanisms and the beneficial role of melatonin. Journal of Pineal Research 52(2):167-202. doi: 10.1111/j.1600-079X.2011.00937.x.
Sasseville A. et al. 2006. Blue blocker glasses impede the capacity of bright light to suppress melatonin production. Journal of Pineal Research 41(1):73-8.
Vangelova K.K. and Israel M.S. 2005. Variations of melatonin and stress hormones under extended shifts and radiofrequency electromagnetic radiation. Reviews on Environmental Health 20(2):151-61.
Volkow N.D. et al. 2011. Effects of cell phone radiofrequency signal exposure on brain glucose metabolism. Journal of the American Medical Association 305(8):808-13.