How Artificial Blue Light (ALAN) Worsens Our Quality of Life

Today, our smartphones and screens have become an essential part of our daily routine. We use them for work, communication, and entertainment. However, we must realize that constant exposure to blue light emitted from these screens is a significant problem for our health for two main reasons.

1. Blue light stimulates melanopsin, which controls (or disrupts) our circadian rhythm.

2. Blue light suppresses melatonin (the sleep hormone), which makes it harder for us to sleep well.

In short: artificial light at night (ALAN) tells your brain that it is still daytime. It shifts your internal clock later and lowers your evening melatonin, so you fall asleep later and sleep worse. The solution follows the natural day: bright days, dim red evenings and dark nights.

Blue light and the circadian rhythm

Blue light is the part of daylight that your internal clock reads most strongly: through melanopsin in your eyes it tells the brain that it is daytime, and when it arrives in the evening, it pushes your whole rhythm later.

Our body has its own internal clock, known as the circadian rhythm. This complex system relies on various environmental cues, including light, to synchronize our sleep-wake cycles. Today it is no secret that blue light, through melanopsin, regulates our circadian rhythm. [R] Researchers at the University of Oxford showed in mice that blue light at night (470 nm) acts through melanopsin, raises the stress hormone corticosterone and delays sleep, while green light brought sleep on quickly. [R]

Timing matters as much as color. In a laboratory study at Harvard Medical School with 21 volunteers, bright light in the evening and in the first half of the night shifted the internal clock later, while the same light in the early morning shifted it earlier. [R]

Exposure to natural light during the day helps regulate the circadian rhythm and promotes alertness, while darkness and red light signal the body to produce melatonin, the hormone that regulates sleep. [R] [R]

However, many people today spend their evenings in front of screens, which causes their circadian rhythm to receive “false” signals. In a Harvard laboratory study, people who read an e-book on a light-emitting device in the hours before bedtime took longer to fall asleep, released less melatonin, had a later internal clock and were less alert the next morning than when they read a printed book. [R] We look at the screen side of this story in more detail in our article on how screens disrupt your circadian rhythm.

Blue light and melatonin

Blue light suppresses melatonin more strongly than other colors of light. When George Brainard's team exposed 72 healthy volunteers to different colors of light at night, melatonin was suppressed most by blue light between 446 and 477 nm. [R]

Melatonin is the main sleep hormone and even helps our mitochondria (the energy transformers of our cells) stay healthy. When we sleep well and avoid blue light sources before bedtime, the melatonin released during sleep helps repair our mitochondria. Russel Reiter and his colleagues summarize laboratory measurements showing that the concentration of melatonin in mitochondria far exceeds that in the blood, and they describe melatonin as an antioxidant targeted directly at these organelles. [R] By their estimate, the pineal gland makes less than 5% of all the melatonin in the body; the rest is made in cells throughout the body, most likely in their mitochondria, where it protects the cell that made it. [R] A review by the same research group links melatonin with mitophagy, the process in which cells recycle damaged mitochondria. [R]

Today there are already many studies on red light, and researchers including Dun-Xian Tan, Russel Reiter and Scott Zimmerman have described how red and near-infrared light (NIR) can stimulate melatonin production in our cells. [R]

This means that not only the absence of blue light in the evening, but also sufficient red and infrared light plays an important role in melatonin production!

In one study of 20 elite female basketball players, it was even found that the athletes who were exposed to whole-body red light for 30 minutes every evening for 14 days experienced better sleep quality and higher serum melatonin levels than the group without light. [R] How mitochondria make their own melatonin, and how light supports it, is explained in our article Melatonin: the key hormone made by mitochondria.

ALAN: artificial light at night

ALAN, artificial light at night, is any electric light that reaches your eyes during your biological night, from phone and TV screens to ceiling LEDs and street lamps shining into the bedroom. It keeps your brain in daytime mode when it should be preparing for sleep.

Today, constant exposure to screens from phones or TVs, especially in the evening, is becoming a serious problem. This phenomenon is called "ALAN" (Artificial Light at Night). When medical students at the University of Niš reduced the blue light coming from their smartphone screens at night, their sleep quality score (PSQI) improved from 6.83, which counts as poor sleep, to 3.93, which counts as good sleep. [R]

And is it really only about the phone? Not at all. In a study of 116 healthy adults aged 18 to 30, ordinary room light (under 200 lux) before bedtime delayed the start of melatonin production in 99% of them and shortened their melatonin night by about 90 minutes compared with dim light. [R] Light during sleep matters too: in a laboratory study at Northwestern University, healthy adults who slept one night with the overhead light on (100 lux) had a higher heart rate during the night and higher insulin resistance the next morning than after a night in near darkness. [R] A review of 85 studies linked artificial light at night with suppressed melatonin, longer time to fall asleep and a disrupted circadian rhythm, with the strongest effects from short-wavelength light and from exposure late in the evening. [R]

The problem therefore does not lie only in excessive exposure to blue light, but also in the lack of red and infrared light. According to many studies, this is exactly the type of light that helps keep us healthier. [R]

Your watch may say 10 p.m., but the light in your room may still be telling your brain that it is midday.

We already have too much blue light! But what about red?

Red and infrared light are what most of us are missing: sunlight is rich in them, while we spend our days indoors under LEDs and screens that contain little red and practically no infrared light.

For thousands of years, people spent their days under the full spectrum of the sun, their evenings by firelight and their nights in darkness. Many of us, in our busy lives, simply do not have enough time to get sufficient healthy sunlight exposure. We wake up for work or school even before sunrise and usually return home only after sunset.

All of us therefore spend too much time indoors, usually under artificial light, especially blue light, and often sitting in front of a “blue-lit” screen. A large US survey of more than 9,000 people found that they spend on average 87% of their time inside buildings and another 6% in vehicles. [R]

So where should the missing red and infrared light come from when we cannot be outside?

"Red and infrared panels Mitochondriak® were created and designed to focus on replenishing these critical frequencies of sunlight that are missing indoors!"

Practical tips to finish

Follow the natural day: get sunlight in the morning and during the day, keep your evenings dim and your bedroom dark, and only then add tools that bring back the missing red and infrared light. If you want to reduce the risks associated with blue light exposure, there are several things you can do. The simplest ones are:

1. Try to spend at least a few minutes outside in natural sunlight in the morning so that your circadian rhythm can stay properly regulated.
2. During the day, try to spend at least a few minutes in sunlight every hour or two, as it contains plenty of red and infrared light.
3. Try to limit the use of electronic devices after sunset, especially screens, smartphones, TVs, etc.
4. If you need lighting in the evening, replace household bulbs with red bulbs that do not emit blue light (or at least with warmer ones), or use candles or a fireplace.
5. If you use screens, learn to use blue light blocking glasses a few hours before bedtime.
6. If you lack red and infrared light and/or are exposed to too much blue light, try to balance it at least partially with appropriate red and infrared panels.

For us Mitochondriaks, the hours between your sun breaks and sunset count as well. When you spend the day indoors with too little daylight, light your room until sunset with an incandescent bulb instead of white LEDs, such as the Incandescent daylight Bulb Mitochondriak® Warm Spectrum E27. Its smooth, continuous spectrum includes a large share of infrared light, the partner of daylight that white LEDs leave out. After sunset, the red bulbs from the list above take over.

For night trips to the bathroom, a red night light with a motion sensor is safer and gentler than a ceiling light, and a piece of red foil over standby LEDs keeps the bedroom truly dark. Which glasses suit which situation is covered in our complete guide to blue light blocking glasses.

If you decide to purchase a red and infrared light therapy device, choose wisely and select a brand that is transparent and provides all the important parameters such as flicker, intensity, percentage flicker, etc. At Mitochondriak®, we list all these parameters in the product description, and based on the measurements our devices undergo, we know they are high quality.

In this short video, we measure our blue light blocking glasses with a spectrometer, so you can see for yourself which part of the light they block.

You can find more tips on improving your sleep quality in this practical article: 5 practical Mitochondriak tips for better sleep.

Summary: what should you remember?

Artificial light at night worsens sleep quality because it tells your brain that it is still daytime: blue light acts through melanopsin, shifts your internal clock later and suppresses melatonin, the hormone that both regulates sleep and protects your mitochondria. At the same time, most of us lack the red and infrared light that the sun gives us. The practical order is simple:

1. Sunlight first. Go outside within 30 minutes of waking and take short breaks in sunlight every hour or two during the day.
2. Then the environment and timing. After sunset, switch off bright ceiling lights, limit screens, use candles or red light, keep regular sleep times and sleep in a truly dark bedroom.
3. Then tools that replace what is missing indoors. Red evening bulbs, a red night light, red glasses for screens, red foil for standby LEDs and red and infrared panels.
4. Supplements last. Synthetic melatonin can help temporarily, for example with jet lag, but it does not replace darkness and we do not recommend it as a routine solution.

Try it for one week: step outside every morning soon after waking, switch to red light after sunset and notice when sleepiness arrives in the evening and how you feel in the morning. For more evening ideas, read how to naturally raise melatonin in the evening.

Frequently asked questions

How does artificial light at night affect sleep quality?

Artificial light at night reaches melanopsin in your eyes and tells your internal clock that it is still daytime. Your melatonin rises later and less, your clock shifts later and falling asleep takes longer. Bright and blue light close to bedtime has the strongest effect, and light during sleep can also raise your heart rate at night.

Does red light at night suppress melatonin?

Dim red light has very little effect on melatonin. In a laboratory study, one hour of blue light at 40 lux reduced nighttime melatonin, while red light of the same brightness did not. That is why we use red bulbs in the evening, while the bedroom itself stays dark during sleep.

Is night mode on my phone enough?

Night mode helps only partially. It reduces some of the blue light, but it does not dim the room around you, does not remove green light and does not eliminate flicker. Putting the phone away after sunset, or at least wearing red glasses that block blue and green light, makes a bigger difference.

What is the best light to use in the evening?

The closer to firelight, the better: dim, low-placed red light without flicker. Red evening bulbs, candles or a fireplace give you enough light to move around without the blue signal of white LEDs. For night trips to the bathroom, a red night light with a motion sensor is safer than a ceiling light.

Should I take melatonin if evening light keeps me awake?

Start with light first. Morning sunlight, dim red evenings and a dark bedroom support your body's own melatonin. Synthetic melatonin can help temporarily, for example with jet lag, but we do not recommend it as a routine solution. If your sleep problems persist, talk to your doctor.

How dark should my bedroom be?

As dark as you can make it. Use blackout curtains against street lamps, cover standby LEDs with red foil and keep screens out of the bed. In a laboratory study, a single night with the ceiling light on raised heart rate during sleep and insulin resistance the next morning in healthy adults.

So, will you join the Mitochondriaks too?

If what you’re reading resonates with you, and if you feel the desire to explore, learn, and share this perspective, you naturally become part of a movement that has the potential to change how people understand health and energy.

If this way of thinking resonates with you, you’re in the right place.

If not, that’s perfectly fine.

Mitochondriak is not a club you sign up for. It’s not an identity you need to defend.

Mitochondriak is a direction. Everyone can walk this path at their own pace, in their own way, and when the time is right. In the end, it’s not about reaching the destination, but about enjoying the journey.

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Sources and references

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