Effect Of Light On Sleep

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Light, Sleep and Longevity: Reclaiming Your Circadian Rhythm in a Modern World

Have you ever had a problem falling asleep at night? Do you know someone who has lost a lot of weight only to gain it right back? Do you know someone who has had cancer? All of these conditions and more¹— diabetes,² heart disease,³ obesity,⁴ infertility⁵—are related to our light environment and, notably, to exposure to the wrong type of light at night. The synthetic junk light (what I call “weapons of mass illumination”) that we’ve installed everywhere—from screens to overhead lights—is affect­ing our biology.

As T.S. Wiley described in her excellent 2000 book titled Lights Out: Sleep, Sugar, and Survival,⁶ the National Institutes of Health (NIH) has known about the light-health connection⁷ for decades—but never told us. When someone once suggested that the American public deserves to know this information, the NIH director’s response was, “Sure, but nobody’s ever going to turn out the lights.” The fact is, though it might be ideal to turn out the lights after dark, there are also other workable solutions to fix your sleep and health—and maybe even live longer.

Numerous studies carried out in recent years have shown that people who get more exposure to sunlight live longer—they die less from all causes than people who get less sunlight.⁸ That is powerful information when you think about the fact that most of us spend 95 percent of our time indoors under “ultraprocessed” light that was never intended to mimic nature. In fact, indoor light encourages us to work longer into the night (or all night long, if you work a second or third shift). Spending more time outside may help you live longer, but in addition, you can mitigate the indoor light environment where you spend most of your time. The purpose of this article is to describe some of the practical strategies readily available to you.

INSOMNIA AND ANXIETY RESOLVED

With a background in chemical engineer­ing, I spent ten years as a research scientist in a pharmaceutical research lab. At the time, I thought I was doing meaningful work. At a cer­tain point, however, I was designing the manu­facturing process for a pharmaceutical product for children, and I had to teach the production people how to make it. There I was, pouring in a fifty-five-gallon drum labeled with a skull-and-crossbones and cancer warnings, wearing a protective “bunny suit” and a respirator—all for a product that was supposed to help kids—and I realized, “I cannot do this anymore.” I decided to get my master’s in holistic nutrition. (One of the courses was on Dr. Weston A. Price—and the textbook was Nourishing Traditions.)

For over sixteen years, I had suffered from significant insomnia and social anxiety. I tried everything to fix these issues, ranging from tak­ing sleep aids to counting backwards from one hundred by fours. But none of the tools or tech­niques I tried solved the problem or answered the question of why I couldn’t sleep.

According to the most recent National Center for Health Statistics data, 30 percent of American adults have used sleep aids (prescrip­tion medications, over-the-counter medications or supplements, or cannabis products) to help them sleep,⁹ while 20 percent use sleep aids regularly.¹⁰ Moreover, only 55 percent of adults wake up feeling well-rested most days or every day.¹¹ Not only do sleeping pills have side ef­fects, they aren’t addressing the underlying problem.

When I started doing some research, I dis­covered many published studies about our light environment. I learned that the NIH has coined the term “artificial light at night” (the acronym is ALAN) and knows of its association with negative outcomes, such as trouble getting to sleep. Referring to blue light (the wavelengths that are beneficial during daylight hours but disruptive at night), Harvard Medical School even published an article in 2024 titled “Blue light has a dark side.”¹²

Nobody had ever told me that our light en­vironment affects our biology. After I decided to make some changes, I not only started to get better sleep but experienced improvements in other areas of my life. For example, working in the pharmaceutical lab, I had never been comfortable giving presentations. After I began experimenting with my light environment and solved my sleep problem, I got a new job, started teaching others and began appearing on major podcasts,¹³ even giving a TEDx talk.¹⁴

How did I achieve better sleep? I put on a pair of blue-light-blocking glasses and made other simple changes described in this article, most of them low-cost or free. My research and personal experiences have persuaded me that our light environment is the first thing we need to fix, and then diet and exercise can follow. Any steps you take toward better health are going to work far better if you first eliminate the negative things in your light environment that are causing your body stress.

THE IMPACT OF ELECTRIFICATION

With the invention of the electric light bulb and the electrification of our country, we went from an agrarian society (originally hunters and foragers) to living indoors about 95 percent of the time. This has had a massive impact on our health. Our biology is tuned in to using natural light to run our hormones and physiological processes, but artificial light was never designed to work with our biology.

Before the advent of electric lights, people were exposed to blue light only during the day.¹⁵ One of the adverse effects of blue-light exposure at night is its impact on the hormone and master antioxidant melatonin, ordinarily produced in the pineal gland during sleep from the conver­sion of tryptophan into serotonin.¹⁶ Melatonin is supposed to get released when our eyes experi­ence darkness, but many of us never experience true darkness. When we sleep surrounded by light-emitting diodes (LEDs), blinking lights, smartphones and so on, it erodes our melatonin and harms our health.

Melatonin is important because it helps turn other hormones on and off, helps turn our im­mune system on and assists us with repair and rejuvenation while we sleep. The release of mel­atonin is supposed to help repair damage from the things in food, air and water that bombard us during the day. Whether the damage comes from glyphosate or electromagnetic frequen­cies or fluoride, our cells need that repair time. Melatonin facilitates this nighttime clean-up.

The “night owl” concept and nighttime blue-light exposure have done our biology a major disservice. Blue light stops the production and release of melatonin for up to four hours,¹⁷ so even if you fall asleep easily and sleep for eight hours, half of your night’s melatonin could be affected. You won’t necessarily feel it, but your body will notice that it’s not repairing and rejuvenating. You might have more brain fog. In my case, I would wake up after eight hours of sleep and feel like I hadn’t even slept.

Interestingly (and regardless of what we may otherwise think of the American Medi­cal Association), the AMA issued a report¹⁸ in 2016 warning about the significant impact on the health of humans (and other species) result­ing from the global transition to “blue-rich” LED street lighting “as the outdoor lighting technology of choice.”¹⁹ The report described white LED streetlights as having “a spectrum containing a strong spike at the wavelength that most effectively suppresses melatonin during the night.”¹⁸ It also noted that LEDs are at least five times more disruptive to the sleep cycle than conventional lighting.¹⁹

The nocturnal melatonin function gets turned off during the day by receptors in the eye, discovered in the 2000s, called melanopsin receptors—what some call the “off switch.”¹⁵ These receptors read light in the blue wave­lengths (whether from a blue sky or artificial blue light), which stimulates cortisol and elimi­nates melatonin. This is what we want when we wake up—high cortisol that allows us to be awake and alert, and melatonin turned off to better regulate insulin—but it’s not what we want at night. When the blue frequency hits our melanopsin receptors at night and shuts down the melatonin, many of us find that we can’t get to sleep. Our mind is racing because of the cortisol stimulation, resulting in an increased stress response that then feeds on itself.

One of our household rules is, “no screens in bed.” A lot of people sleep with their cell phone in the bedroom. If you do this, at least put it in airplane mode (it will still work as an alarm clock), dim the phone and keep it some­where out of sight; you don’t want to be blasted with bright light that is going to significantly decrease your melatonin.

CIRCADIAN RHYTHM

Circadian rhythm is the natural twenty-four-hour cycle built into our biology, run by light and dark cycles. Every cell in our body and every organ has a clock, and that clock is set by light through the eye. Circadian rhythm is what keeps us optimally healthy. In 2017, this fact received official acknowledgment through the award of the Nobel Prize in Medicine to three researchers for their discoveries of some of the molecular mechanisms controlling circadian rhythm.²⁰

When we’re exposed to the right type of light, things work well. However, most people are not getting outside at dawn, and they’re see­ing a lot of artificial light after sunset. Before the invention of electricity, post-sunset light was limited to firelight and moonlight; because firelight provides red and yellow but not blue light, it is not disruptive to melatonin or sleep. Modern lights are. With the unnatural blue lighting that is poisoning us indoors, is it any wonder that people have “seasonal affective disorder” in the winter?

Because the sun rises and sets at different times over the course of the year, our circadian rhythm tells us what season we’re in. It is no ac­cident that in winter, some animals change their coats or gain more weight or hibernate—they get those signals from the light. And we get those same signals. Just as animals store sugars as fat for the coming winter, we do the same thing. The problem is that for us, winter never comes, because we keep the lights on all winter long. Our bodies think that winter is coming and store fat from abundant carbohydrates (think of fall fruit and Thanksgiving and holiday pies!), but from a circadian rhythm standpoint, winter never arrives.

LIGHT FIRST

Wise Traditions readers and Weston A. Price Foundation members are rightly com­mitted to the importance of nutrition, but let me tell a story that illustrates why addressing one’s light environment should be a top priority. In fact, if you are neglecting your light environ­ment, you don’t have the full picture of how to be optimally healthy.

My friend Todd was a “biohacker,” someone who knew just about everything about health, nutrition and diet. He was eating all the right foods, and he had every “biohacking” gadget and device that money can buy, but he had forty-five pounds to lose, and for a year and a half, he couldn’t figure out how to lose them. About two months after he came to one of our retreats, where he learned about light, he sent us the following email: “You’ll never believe this. In just six weeks, I lost the forty-five pounds, and the only things that I did differently were to go outside at sunrise and wear blue-light-blocking glasses at night.” He made no other changes; just shifting his light exposure allowed him to lose that stubborn weight.

Researchers have observed this phenom­enon in mice, too.²¹ In one study, two groups of the same types of mice had identical diet and exercise regimens, but one group was exposed to twenty-four hours of light in their cage, while the other group had twelve hours of light and twelve hours of darkness. The mice continually exposed to light became obese, whereas the mice exposed to twelve hours each of light and darkness remained normal weight. Light was the only variable in their living conditions that was different. Todd’s story and these types of studies confirm that light is a “big deal.”

MORNING SOLUTIONS

The good news is that light is a relatively easy thing to fix. A good first step is to do what Todd did: get outside at dawn (meaning within thirty minutes of sunrise). It’s completely free, it’s backed by research and it’s designed to work with our biology. It is how nature created us. Obviously, the time of sunrise changes with the seasons. It will be earlier in the summer and later in the winter. Some people argue, therefore, that it’s “inconvenient” to get outside at sunrise, but I would argue that cancer, obesity and diabetes are even more “inconvenient.”

What is so important about dawn light? Light at dawn is different from light at any other time of the day because there is no UV light at dawn. What the lack of UV light means is that, while you’re not going to get more vitamin D, men will get a significant increase in testoster­one, and women will get a significant increase in estrogen. The no-UV light turns your hormones on. It also sets your melatonin clock—sixteen hours after you see the sun rise in the morning, your melatonin is triggered to be released. There are studies showing that you sleep better at night, literally just by getting outside at dawn.²²

When you go outside at dawn, there is no need to stare directly at the sun. Just being out­side at that time of day will start to allow your eyes to become less sun-sensitive. In fact, even people with blue eyes, said to be more sensitive to sunlight, can retrain their eyes by regularly going outside at dawn. As for how long to stay outside, around eighteen minutes is ideal, but even two to five minutes of morning sun will have quantum effects on your biology. If two to five minutes is all you can manage, it’s still worth doing. People also ask me what to do if they live close to a mountain (where they don’t get the morning light until later) or about the impact of cloudy, foggy or rainy conditions. I tell them that doesn’t matter. As long as you get outside within thirty minutes of sunrise, the light is reaching your eyes.

During the day, there are a variety of other ways to improve your light. If you are in your car commuting to or from work, roll your window down or open your sunroof. If you are at home, open a window. Even if it’s winter or I am stuck in a Zoom meeting, I will open a window. (This is because closed windows allow all the blue light in but none of the UV, and they eliminate 50 percent of the red and infrared.) I have been working remotely for eighteen years, a work routine that I designed on purpose so that I could have a better light environment and do some exercise during the day. Sometimes, I still have to go back to corporate headquarters, so if I’m there, I’ll have a red light shining on me. You can also go outside and take “light breaks” (just like people used to go outside for smoking breaks). All of these things are circadian cues. Light has quantum effects in our body, so even a tiny amount has a big impact on our biology.

If you are a coffee drinker, do not drink your coffee until after you see the morning light, or even a little while later, because coffee itself is like a shot of cortisol. If you haven’t seen the natural sunlight to clear the melatonin and set the right amount of cortisol, coffee will make your cortisol go much higher, and this can cause stress and anxiety. [Editor’s note: WAPF does not recommend drinking coffee.²³]

Another tip that is very helpful, especially for people who are trying to lose weight, is to have the first meal of the day no later than thirty minutes after seeing the sunrise. Even better is to make it the biggest and most protein-heavy (fifty to seventy-five grams) meal of the day. [Editor’s note: WAPF recommends ample ani­mal fat with your protein.] As Dr. Jack Kruse emphasizes in his Leptin Reset Protocol for Weight Loss,²⁴ eating soon after waking helps to reset leptin, which is the hormone that signals the brain when you’ve had enough to eat and regulates body weight. Seeing the sunrise and then eating your first meal within thirty minutes not only resets your circadian rhythm but resets leptin and can help you lose weight.

These days, many people practice intermit­tent fasting, eating just two meals a day. This can be a helpful thing to do, but I would argue that it is not a good idea to skip the morning meal, especially as you approach the shorter winter days or if you are a coffee drinker. (Intermit­tent fasting in the morning followed by coffee can be a massive stressor on the body.) Studies show that people who eat their last meal after sunset weigh more than people who eat their  last meal before sunset.²⁵ We gain weight when we eat too close to the time when our cells are trying to rest and digest. Even if you eat three meals a day, it’s ideal for sleep and circadian rhythm (especially when the days are shorter) to eat your biggest meal in the morning and a smaller last meal around 4:30 p.m. In addition, for people who are prone to anxiety or stress, eating in the morning can lower cortisol and make them feel calmer.

Parents object that an early dinner is inconvenient when children are involved in after-school activities. In our case, my wife and I would eat early and then prepare dinner for the kids later and join them at the dinner table without eating ourselves.

EVENING LIGHT

One thing that most of us are not going to do is go to bed when it gets dark. However, think about our ancestors a century or two ago. Candles were expensive. When it got dark, there were only so many candles one could afford to burn, and so, shortly after dark, people went to sleep. According to some estimates, people in 1910 slept, on average, five hundred hours more each year than they do today.²⁶

If you’re not getting great sleep and you want more sleep, you could try switching to firelight or candlelight after dark, but again, most people are not likely to do this. In our case, we did install a woodstove, which provides both firelight and heat. With that said, if you are going to be out and about at night, or your family is not willing to forego screens or lights at night, then this is where blue-light-blocking glasses come in. Remember that the melanopsin recep­tors will read the blue light (which increases cortisol and clears melatonin), but if you put on a pair of those glasses, they will block the blue wavelength of light.²⁷ You don’t even have to change your home lighting. These days, there are many brands of high-end blue-light-blocking glasses, but you can also just buy inexpensive Uvex orange safety glasses. Spend two weeks wearing a pair of blue-light-blocking glasses after sunset and see how you sleep and feel. For me, it made all the difference in the world.

The next step is to take stock of your bed­room. You should have a pitch-dark bedroom when you sleep. That means no phone charging, no blinking lights, no illuminated clocks and no light-emitting devices of any kind. To block out light coming in from the street, blackout curtains are very helpful. Alternatively, you can wear an eye mask. When I travel, I bring an eye mask and also carry black electrical tape to cover up those annoying little lights in hotel rooms. Another hotel trick, when you can’t get the blackout curtains to stay closed, is to take one of the hotel coat hangers (the kind that has clips for pants) and use it to clip the curtains closed!

WHAT ABOUT LIGHT BULBS?

With the ban on incandescents (supposedly now reversed, though they are still hard to find), many people installed “energy-saving” LEDs. The problem with LED or fluorescent lights, and even with incandescents at night, is that they have too much blue light. LEDs became more popular around 2005, which is when manufacturers figured out how to make white LEDs. The white lights use a blue LED chip, a driver that turns on and off with every cycle of the electricity. (In the U.S., that is something like sixty times a second.) Philips credits itself with being “at the forefront of LED lighting de­velopment,”²⁸ and they charge anyone who sells LED lights a fee because—in a genius business move—they bought every company that had anything to do with LED patents. Your phone screens, tablets, televisions, overhead lights and refrigerator lights are all based on the blue LED drivers, which produce exactly the wrong type of light for our nighttime biology.

Color temperature is a way to describe the color appearance of the light provided by a light bulb, measured with a spectrometer in degrees Kelvin, generally on a scale from one to ten thousand. Lower Kelvin values indicate warmer and more golden light (more yellow, red and orange); higher Kelvin values indicate cooler, brighter, blue-white light. An LED in what I consider to be a more tolerable eighteen hundred range will look like a warm amber LED.

You can buy “blue-free” LEDs, but in our house, we primarily use red lights. (If you look at our house from the outside, it looks like Hal­loween.) This is because the red lights don’t impact melatonin. In our bedroom, we have one red light (for evening) and one incandescent light (for daytime), and we can turn them on separately. We have the same arrangement in our bathroom—regular bright white lights for daytime, and red and infrared lights for evening. We also have a red strip light down our hallway. The only room where we don’t recommend red lights is the kitchen. (If you cut yourself, you can’t see the blood because everything looks red!) Speaking of the kitchen, I also taped 3M Red Lens Repair Tape over the bright blue LED refrigerator bulb.

Admittedly, red lights in the home are not for everyone. If you don’t want to go that route, you can get blue-light-free amber lights that look a little more natural, or you can use salt lamps because their light is orange and red. And even if you do nothing else, it makes a big difference if the lights you use at night are lamps positioned at a lower level than overhead. Overhead lights are more harmful at night because of the angle at which the light reaches your eyes.

WEAPONIZED LEDs

In December 2020 in Wisconsin, I was driv­ing to an evening event where I was a speaker. At that time of year, it gets dark at 4:30 p.m. I was running late, and I missed the exit on the highway. As I tried to get to the next exit to turn around, a state trooper pulled me over. The trooper looked at me and said, “Can you take your glasses off?” Then he asked, “Are those blue-light-blocking glasses you’re wearing? Do they protect your eyes against these ridiculously bright LED headlights?” I let him try them on, and he said, “Okay, you can go.” Not only did I get out of a ticket, but I guarantee that the state troopers in Wisconsin are now wearing blue-blocking glasses!

I call those LED headlights “weaponized headlights,” and even the 2016 report by the AMA warned about them. If you drive at night, you know how bright they are. I keep multiple pairs of blue-light-blocking glasses in my console so that when those headlights are flashing me, I can put them on and protect my eyes. (A friend of mine found that inexpensive red DeWalt laser enhancement glasses can help tone down those headlights.) That intense level of brightness at night will trigger destruction of your melatonin and higher cortisol. There is no reason for them to be so bright—they could be more yellow and still work very well.

All LEDs are going to flicker, unless they’re on direct current (DC). That’s just how the chip works. The flicker can cause stress and migraines in some people. LEDs flicker at a rate that our brain notices but our eyes generally don’t see. (With some LED lights, however, you can see the flicker, especially if you take a video of the light.) Therefore, it’s impor­tant to get the right type of LEDs—those with no or low flicker—or get incandescent bulbs. (A good resource for questions about flicker is the red-light therapy company GembaRed.²⁷)

Some people will go so far as to run their lights off of DC to address the flicker problem. More companies are coming out with DC technolo­gies. Battery power also achieves the same result, so some people use a battery-powered night-light, reading light or desk lamp. We use battery-powered reading lights that are amber and red, which also helps mitigate electromagnetic frequencies. Another solution is to find an LED that has higher flicker to the point where the brain can’t detect it (look for the terms “color rendering index” and “flicker percentage”). Once the flicker gets high enough, your brain perceives it as always on. Building biologists also recommend getting rid of dimmer switches, which are problematic from a dirty electricity standpoint.³⁰

HOW MUCH SLEEP?

Most people think we need eight hours of sleep every night, because that’s what we’ve always been told. However, if you go to bed earlier (or wake later) in the winter, sleeping at least nine and a half hours, then you won’t need to sleep as much in the summer. In summer, the days are longer, and there is a lot more to do. You’re harvesting, you’re collect­ing berries or you’re out late with friends. Researchers found that mice who slept for nine and a half hours were unable to get cancer despite the researchers trying to give them cancer—and the study even used mice engineered to be predisposed to cancer!

Think of winter as the time to focus more on things that wind you down—such as prayer or family time. And if you go to bed earlier and/or sleep later—even if it’s only half an hour earlier or later—you will begin to reverse whatever you did in the summer. You will feel better, with less brain fog and more motivation.

STEPPING INTO THE LIGHT

What would our ancestors have done? They would have been outdoors much more often. They would have gone to bed earlier in winter. They would have had no exposure (and no ability to be exposed) to blue light. At night, they would have had firelight, candlelight and moonlight. Our bodies were not designed for the artificial lights with which we now surround ourselves.

If you take nothing else away from this article, remember that spending more time out­side can help you live longer. Getting outside at dawn (and bonus points if you are barefoot and grounded) and doing a little bit of movement will help you clear the melatonin. If you follow that by eating your largest meal of the day, you are resetting your circadian rhythm and lowering your stress for the whole day. Better light and sleep will help your body repair damage and rejuvenate.

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SIDEBARS

 

DITCH THE SUNGLASSES AND SUNSCREEN

Our ancestors were always exposed to the right type of light. Our biology knows how to make intelligent use of sunlight—no sunglasses required. Originally, sunglasses were designed for Hollywood movie stars who were exposed to bright studio lights; they were not designed for outdoor use. Then Sam Foster of the Foster Grant brand started mass-producing sunglasses so that ordinary people could look like movie stars.

When we put on sunscreen, cover up and wear hats and sunglasses, we’re eliminating our exposure to nature’s light. Our eyes not only have melanopsin to read blue light, but neuropsin receptors to read ultraviolet light. We need to read all the spectrum and frequency of light as nature designed. There are better ways to practice safe sun exposure and build up what Dr. Jack Kruse calls a “solar callus.” Kruse colorfully says, “We would not place a tarp over an orange tree and still expect the tree to bear fruit.”

 

BLUE-LIGHT-BLOCKING GLASSES

Before my wife and I started our company DreamWalkerz (dreamwalkerz.ai), I had tested just about every pair of blue-light-blocking glasses out there. I found that there is wide variation in the blue-light-blocking tint. Some glasses are clear; when they say that they block blue light, they probably do, but it may be only 2 percent, which is not nearly enough at night. At night, you ideally want to block 100 percent of blue light, and lenses that do that generally will look orange. Some companies offer red lenses that block 100 percent of blue and green light (because some people are sensitive to green light as well), but you can’t see enough in those red lenses, so I do not find them practical. Our company makes amber or orange lenses that block 100 percent of the blue. Because they don’t block so much of the light that you can’t see anything, we think that people are more likely to actually wear them.

There are a number of solutions for people who wear prescription glasses. If I had prescription glasses, I would probably get two pairs of glasses—one for daytime (yellow) and one for nighttime (orange). However, not all blue-blocking companies will do prescriptions. Alternatively, the VivaRays company offers magnetic clip-ons, with day and night versions, that you can use over your prescription glasses, and that would probably be cheaper than buying two pairs of blue-light-blocking prescription glasses. A third option is to see if your optometrist is willing to put a blue-light-blocker on your prescription (it is called BPI 550 tint).

 

FLUX FOR YOUR COMPUTER

The f.lux app—which is free—can lower or eliminate blue light on your computer screen and even make your screen emit red light at night, if you wish. The program reduces blue wavelengths and shifts your display to warmer tones at sunset, supporting natural circadian timing.

You can install f.lux on a Mac or PC laptop, but none come with it pre-installed.

To install f.lux on your laptop, go to https://justgetflux.com. Click “Download” and run the installer for your operat­ing system. Then open f.lux and allow any system permissions it requests. Enter your location or allow location access so f.lux can set sunset/sunrise automatically. Choose a color temperature preset (I recommend Amber 1900K). For night use, select the lowest comfortable color temperature setting. You can also set an optional bedtime schedule.

Itʼs also possible to get equivalent f.lux protection on phones.

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