How Light effects Melatonin and Sleep
You heard me mention color temperature before, and the effect of watching TV or reading on the iPad before bed (See Sleepy Yet? — How Light from Electronics Effects Sleep), but here’s why it’s important.
This WebMD article examines the hormone melatonin, which helps regulate sleep & wake cycles (the circadian clock). Melatonin production in the body is triggered by darkness and inhibited by light, and that explains why we have trouble with jet lag, shift work, and winter months with fewer daylight hours.
This Wikipedia article describes light therapy and melatonin supplements as treatment for sleep disorders like insomnia. It also describes the light color temperature, from the warm yellow of incandescent light bulbs, to blue light of the new fluorescent and LED bulbs, or the bluish tint of the iPad and TV screens.
One way to fool the body into producing melatonin earlier so you can go to sleep earlier is to select warm-color light bulbs and have them dimmed in the evening. Another way is to wear DARK AMBER or ORANGE sunglasses in the evening to block blue light (short light wavelengths). And of course, that’s why sleep experts advise against using a computer or watching TV shortly before bed.
Because my wife and I often watch TV immediately before bed, and she likes to look at videos of our granddaughter on her iPad then, I checked the iPad Settings and found a way to dim the backlighting intensity and set it to somewhat adjust automatically depending on the ambient light. Go to Settings / Brightness & Wallpaper.
I’d also like the iPad to change the color temperature at night but found nothing native in the iPad, so I searched for a reliable iPad app for that. I found iJetlag and TheSleepApp but was disappointed with both of them. One even used the wrong color of light to encourage melatonin production and encourage sleep.
Additional sources of sleep information include the two articles on this site by PhD sleep consultant Bruce Meleski (Sleep Balance – Your Path to Better Sleep and Brain Entrainment for Better Sleep and Health) and in Jeanie Wolfson’s article on Sleep: Timing of Melatonin, Light, Dark, & Use of Other Aids. Wolfson lists many suggestions for improving sleep, including these few:
- Keep bedroom dark or wear an eye mask.
- Keep room cool and feet warm.
- Find a mattress that works for you, trying harder, softer, coil, foam, gel, waterbed, or hammock.
- Block distracting sounds with white noise.
- Use lighting controls to simulate dawn before alarm sounds.
- Don’t watch TV, use a computer use, or do homework within an hour of going to bed.
- Avoid caffeine and snacks that can cause a blood-sugar drop during the night.
- Establish a strict sleep/wake schedule.
- Exercise regularly.
RELATED ARTICLES:
2024 Lighting Controls & Fixtures — This CEPro Deep Dive Report summarizes the lighting industry’s premier lighting conference – Lightapalooza – and suggests the lighting industry has a bright future with a focus on human-centric lighting, also called circadian lighting.
Do Blue Light Blocking Glasses Do Anything? A Review of The Research, by Dr. Ceppie Merry
EDITOR COMMENTS: Public awareness of the importance of sleep has caused manufacturers to introduce many new products, from bedding to light bulbs, glasses, and software apps, often with unsubstantiated claims. Dr. Merry’s in-depth article about blue light blocking glasses cites 26 scientific papers and reviews 8 popular claims about improved sleep and other health effects. The folks at her firm asked me to share it with you, and I do so with these additional comments. (Be sure to follow the link above for her analysis.)
CIRCADIAN RHYTHM — According to Dr. Russel J. Reiter, the world expert on Melatonin, this important molecule is found in every living organism, having evolved through millions of years of evolution to counter the oxidation harm caused by cell metabolism. Melatonin is nature’s strongest antioxidant, is critical to cell health, and is produced by the pineal gland as part of the circadian rhythm regulated by light and the day-night cycle. This natural cycle triggers behavior, whether signaling time to sleep or time to hunt. But as we age, we produce much less of it, and that’s worsened by the fact that artificial lights interfere with our biological clock. Ritter says there’s no such thing as taking too much Melatonin. Contrary to popular belief, taking supplements does not lower production of more from the pineal gland, since that’s entirely driven by the day-night cycle (actually by darkness). Ritter takes 30mg/day and keeps 150mg on hand in case of an emergency (heart attack or stroke), with strict instructions to give him Melatonin before oxygen.
ARTIFICIAL LIGHT — Artificial electric light has had a profound effect on human behavior, allowing us to work more but causing us to sleep less – almost two hours less than before Thomas Edison’s light bulb. That’s not natural and goes against evolution. Light color is also important, and we’re already seeing negative consequences of the bluish light of LED bulbs and backlighting of electronic devices. The fact that street lights and car headlights are using this energy-saving LED technology is also troubling, especially for shift workers who have trouble sleeping after staring into oncoming lights as they drive home.
HOME LIGHTING — In previous articles and lectures, I’ve described simple corrective actions around the home, giving all nighttime artificial lighting an orange hue. When buying LED bulbs for efficiency, look for those with the warmest color temperature, and dim them if your activity allows. If your clock radio has a white or blue face, replace it with a clock with a red face, or just turn it away so you can’t see the display at night. LED nightlights have way too much blue and can make it difficult to go back to sleep if you briefly wake up to go pee, so I suggest sticking with older models, replacing the incandescent bulbs with orange bulbs, or adding some sort of orange filter.
SMART LIGHTING — Philips was an early developer of smart lighting, with its color-changing Hue series. Dr. Merry’s article mentions the potential of using light to control mood, and Philips certainly plays in that space. They’ve even used lighting colors to control the mood, attention, and focus of school children, as shown in this video:
SMART SOFTWARE — Software that first appeared as apps to control the color of LED backlighting in phones, tablets, and PCs has finally been replaced by operating system settings. All of my devices now lower brightness intensity as the sun goes down and start removing blue light, leaving the screen with an orange tint while giving me the ability to override default settings if needed.
GLASSES & FILTERS — Wearing Amber Glasses at night can minimize the amount of blue light seen at night, but only wear them at night. Get bright light exposure as early as possible in the morning to also help regulate the circadian rhythm. If that’s not possible due to northern exposure or weather, resulting in seasonal effective disorder (SAD), use bright full-spectrum lights in the morning.
HEALTH IMPACT — Dr. Merry’s report also examines various claims of positive health benefits of wearing blue light limiting glasses but seems to discount many manufacturer claims. Without arguing those points, I want to say that some of the health impacts of managing artificial light are related to improved production of Melatonin and its antioxidant role in fighting disease. Other benefits come from what happens in the body during the different stages of sleep, such as hormone production and activating the limbic system for waste cleanup. Here are some ways sleep wellness improves overall health:
Obesity – Sleep duration plays a role in regulating body weight and metabolism, because when sleep deprived, your body creates less leptin and more ghrelin. While leptin suppresses your appetite, ghrelin makes you crave carbs and is known as the hunger hormone. About two thirds of American adults are now overweight or obese, and we spend nearly $200 billion/year treating obesity-related illness.
Diabetes – Sleep deficiency increases the diabetes risk by 250%. Already, some 26M adults & children have diabetes, 79M are pre-diabetic, and every 10 seconds a person dies from diabetes related causes.
Heart Disease – According to a 2011 European Heart Journal review of 15 medical studies involving almost half a million people, sleep deficiency increases the risk of heart disease by 48%. So with over 600,000 Americans dying each year from heart disease, some 300,000 are likely related to sleep deficiency.
Stroke – The one third of working adults who sleep less than 6 hours a night are 4 times more likely to suffer a stroke. Each year about 800,000 Americans have a stroke.
Breast Cancer – Researchers in Japan found that women who slept less than 6 hours a night were 62% more likely to develop breast cancer than those who slept 7 hours. Other studies found that women who do shift work, such as nurses, have a higher risk of developing breast cancer than those who work during the day. That’s likely because of how light and melatonin regulates circadian rhythms. Sleep also affects recovery, and one study showed a 1.5-fold increased risk of dying from breast cancer among women who slept less than 5 hours a night before diagnosis compared to those who slept 7 or more hours.
Immune System – A well functioning immune systems protects us from colds, flu, and other ailments, but when poor sleep interferes, it fails to do its job. People who slept less than six hours a night were over four times more likely to catch a cold than those who slept over 7 hours.
Depression – Poor sleep is a contributor. A 2007 study of over 10,000 people found that insomnia increased their chance of suffering from depression 5-fold.
Alzheimer’s – Several new research studies have linked poor sleep to the loss of brain tissue, Alzheimer’s disease, and other dementia and neurological disorders; but it’s not yet clear just how much impact it has.
Premature Death – People who sleep less than 6 hours a night are 20% more likely to die in 20 years.
Birthrate – Declining birthrates are troublesome, because as boomers enter retirement years and live longer, they leave fewer young workers to contribute to the tax base and support social programs the elderly depend on.
Sources – This list of ways sleep affects health is taken from a a white paper I started years ago on “The Economic Benefits of Population Sleep Wellness” but never completed. I removed the reference links but can say the stats are from hundreds of articles published in scientific journals and mainstream media.
Blue light makes us hyper – can red light calm us down?
The blue part of the light spectrum is very strong in smart phones, tablets, television and other electronic devices with light-emitting screens. Blue light affects the biological clock and sleep-regulating neurons in the brain. Evening exposure, therefore, can make it difficult to settle down in the evening for a restful night of sound sleep.
Research has focused so strongly on blue light, that other colors of the spectrum have been neglected somewhat. Van der Meijden and colleagues from the Netherlands Institute for Neuroscience in Amsterdam have now for the first time systematically evaluated what happens after exposing ourselves to many minutes of intense red light only.
Prior red light exposure had some unexpected effects that were mostly opposite to the effects of blue light. After red light, it took participants more effort to perform a task requiring attention. Their reaction times also slowed. Most surprising, prior exposure to intense red light also made it easier to fall asleep. The findings, published today in Proceedings of the Royal Society B: Biological Sciences, suggest that red light might counteract some of the adverse effects of blue-light emitting screens. Red light may even turn out to be useful as night cap.
You can invert the the colors on an iPad which makes white backgrounds black. It’s great for reading (I use it every night) but not so good for videos or images (like looking at film negatives). Hit the home button 3 times in a row and it’ll bring up a menu.
Thank goodness the news is starting to report on this. I use the SleepShield iPad filters (http://j.mp/LlcvDr) and they work great. I also put the new Good Night LED Sleep Lights in my bedside table (http://j.mp/1f9udlO).
Thanks, Jeff, for your response. The SleepShield filters seem like a good idea, at least until Apple modifies iOS to support a software solution like flux (See comment at https://www.mhealthtalk.com/2013/02/sleepy-yet-how-light-from-electronics-affects-sleep/).
I smell “snake oil” in the Good Night LED Sleep Lights, however, because of the wild claims, my understanding of the physics, and the lack of evidence substantiating their claims. Sorry, but an endorsement by Dr. Oz is not enough since he lacks credentials in this space. Here’s some info from the CES trip report I’m finishing:
I’ve long been a fan of the Philips Hue light bulbs, which you can buy at the Apple store, because you can turn them on & off, control intensity, and even control COLOR TEMPERATURE through the iPhone. What makes that a great feature is how artificial light affects melatonin and sleep. But the Philips bulbs are expensive and require a Zigbee wireless network hub, so I was happy to see new competitors
Belkin’s WeMo Smart LED Bulbs and home automation kit uses your Wi-Fi home network and allows you to control, schedule and dim your lights from anywhere. The 60-watt bulbs are brighter and last longer than the Philips Hue but have a fixed 3000-Kelvin warm white color (arguably less blue light). Fully dimmable, WeMo Smart LED Bulbs can be controlled individually or in groups. The Starter Set includes two LED Smart Bulbs and a WeMo Link, which can support up to 50 individual Smart bulbs.
Individual WeMo Smart LED bulbs will be sold separately.
YiFang Digital introduced a Bluetooth-connected smart lighting system that gives users similar control over their home lighting through a free app for iOS or Android devices. It allows them to turn the lights on or off; control brightness, color & preset scenes (e.g. Romantic, Movie, Dinner, Relax, Sleep); and program lights to change automatically throughout the day. The system supports 4S/5 and Samsung Galaxy S4 smartphones, and as with most other Bluetooth devices, it has a working distance of about 30 feet.
The BeeWi LED light bulb also has many of the same features at the Philips Hue, including adjustable colors, but it’s much cheaper (less than $40 per bulb), brighter (60W equivalent), and uses Bluetooth instead of Zigbee (no need for a separate hub). One problem with the Bluetooth connection is that you can’t control the lights remotely, but an optional “Smart Gateway” solves that and bridges between your Wi-Fi home network and Bluetooth, thus giving BeeWi users the best of both worlds.
The Withings Aura (0:54 video) has a sensor pad that goes under your mattress to monitor your sleep and help wake you up gently. It plugs into a bedside alarm clock, speaker, and LED table lamp, where colors and sounds simulate dawn and dusk. With selected light colors, it can inhibit or trigger the body’s production of the hormone melatonin and either wake you or help you relax and fall asleep.
Withings says the mattress pad picks up “micromovements” that are far more sensitive than most wristbands and activity trackers. The sensor can even detect tiny movements from under a pillow-top or tempurpedic mattress, which is designed to minimize movement. Separate sensors can monitor sleep patterns for two people in the same bed, and it detects not just movements but also breathing and heart rate. This allows Withings to make much more sophisticated conclusions about that nature and quality of your sleep. With this data, the Aura alarm unit can wake you when it makes sense, rather than abruptly at a specific time.
The $299 starter kit includes one sensor pad and one nightstand alarm/light. >
I really enjoyed this article as I am trying to find out as much information as possible so that I can be assured that I am getting the best rest possible. One last thing that I didn’t see mentioned is just to try to get as much natural sun light as possible or going to a tanning salon during the day for what you deem and appropriate amount of time. Both have helped me the past and others that I know.
Thanks for your reply, Thomas. Getting enough natural sunlight during the day can certainly help program your biological clock and circadian rhythms. Also helpful is high-intensity and full spectrum lights or just positioning your desk by a window, but I don’t recommend tanning beds even in winter due to the cancer risks.
Incandescent bulbs are so called because of the heat produced. Incandescence means to glow with heat. The tungsten filament is found inside a void within the bulb. When energy is pumped through the wire, the electrons react and there is resistance. Then, the filament will get so hot it will glow.
(Editor: The light from a hot filament is somewhat like the light from a campfire, i.e. warm coloration, as opposed to the blueish or greenish light of fluorescent lights. I also removed a potentially dangerous link.)
Dear Mhealthtalk,
This might be off topic, however, Dear Mhealthtalk,
I was wondering on a similar note,, The patio or the backyard is a place where the family can entertain guests, hold parties or just hang out with each other. It can be a place for dining, cooking barbeque, playing cards or maybe even swim in a pool. All of these activities usually take part during nighttime that is why the right kind of patio lights should be chosen to provide the right amount of lighting in the patio.
Great Job!
Thanks
Here’s a great resource about the affects of Light on Sleep Quality and General Health:
Light & Health Research Foundation (SOLG) — http://www.solg.nl/
CLICK the British flag at top/right for an English version.
Also, I posted a link to my Economic Value of Good Sleep article in a Linkedin group on Light Therapy, and it has started a discussion of sleep benefits among sleep experts worldwide.
Douglas Steel pointed me to the website for the National Sleep Foundation (www.sleepfoundation.org) and several statistics there, but I found them less than credible and responded:
Light therapy works for 90% of users and this one time investment intrigues more and more people. Light therapy seems to be a universal solution and you can now own acne lights for home use.