How Blue Light Affects Your Hormones, and 5 Natural Ways to Combat Its Negative Effects
A few weeks ago, I was happily zoning out on an Amtrak train traveling from New York to Baltimore. It was an evening train, so there wasn’t much birdwatching or sunsets left to take in from my window seat. On evening trains, the cabins are still heavily lit, so the catnap option was out too. As if one of the conductors heard my pleas of boredom and fatigue, the train went over a portion of track that disconnected from the overhead electrical wires. Ah, finally – time to sleep. Except, when I looked around, the cabin was still bright. The lights were turned off, but every passenger in every seat had a device open that was emitting a bright blue light.
It’s become a rarity to see someone who’s NOT on their device. It’s like seeing a bald eagle – and I would know, I have seen one on that same Amtrak route. Don’t get me wrong, devices are great. I love my iPhone; it makes life easier and more fun. But what if I told you that the blue light your devices emit negatively impacts your (and your kids’) hormones in a big way? Would you still be perusing Instagram or Netflix as much?
What’s blue light?
Blue light is part of the visible light spectrum. Sunlight contains the full spectrum: red, orange, yellow, green, blue, indigo, and violet. When combined, it’s the white light you see when you go outside. Generally, the whiter the light, the higher the amount of light from the blue end of the spectrum. Other than sunlight, the largest sources of blue light you’re exposed to are from computer monitors, smart phone and tablet screens, fluorescent lights, LED lights, and flat screen LED televisions.
All forms of light serve different physiological functions in the human body. Blue light sets the circadian rhythm in your brain, which in turn regulates various neurotransmitters and hormones that affect the rest of your body. Your circadian rhythm determines when you sleep and when you’re awake, and it’s heavily influenced by exposure to waves of blue light.
Through our eyes, our pupils respond to light to inform our brains what time of day it is. When we first wake up and open our blinds, bright sunlight floods our vision, and a part of our brain called the suprachiasmatic nucleus (SCN) gets the message that it’s go time. Our cortisol levels rise, we become alert, our digestive system kicks in and we usually head to the bathroom, and our appetite kicks in as our metabolism revs up. Then, as the sun goes down and bright light in our environment decreases, our eyes and SCN inform our pineal gland that it’s time for bed, and it starts secreting melatonin, the “sleep hormone.”
There are receptors in various tissues of the body (not just the brain), that see melatonin and bind to it, telling those parts of the body it’s time for rest and renewal. You become less alert, cortisol levels wane, sleep becomes more inviting, and cells of your body enter a more chill repair phase in contrast to their diurnal working-girl mode. All sounds perfectly balanced, right?
Well, problems arise when we override this central pacemaker’s signals, throwing not only our sleep-wake cycle out of alignment, but various other downstream rhythms suffer too – especially your hormones.
And the primary way we do this is through exposure to artificial blue light – too much of it altogether and especially at the wrong times.
3 ways blue light messes with your hormones
it can lead to weight gain
The SCN helps to synchronize all of the body’s clocks. It’s like Big Ben and our cells are like the 2,000 other clocks in the Houses Of Parliament that look to Big Ben for an accurate setting. The SCN accomplishes this directly, by nudging the pineal gland to produce some melatonin, and indirectly, by influencing when we eat, thus activating digestive function and enzymatic release at opportune times.
As humans with the luxury of eating whenever we want, we don’t really pay attention to our biological clock. To demonstrate the consequences of such behavior, a study was performed that altered the natural feeding time of mice, who are naturally nocturnal animals. One group of mice was fed a high-fat diet only during the day, and the other group of mice was fed the same exact diet but at night (their normal feeding window). Both groups were given the same amount of calories and had similar activity levels. After six weeks, the mice fed during the day gained significantly more weight and had more body fat than those fed at night.
While we are not mice, this may serve as a cautionary tale to those who are consistently out of sync with the body’s natural eating schedule (i.e late night eaters). By overriding the SCN’s signals, you throw natural rhythms that are designed to keep you feeling and looking your best out of whack. Coupling this with limited exposure to sunlight during the day and overexposure to artificial light at night, we confuse our SCN and our body’s clocks even more! So, the age-old saying can be updated from, “You are what you eat,” to “You are what you eat when you eat it.”
So the age-old saying can be updated from, “You are what you eat,” to “You are what you eat when you eat it.”
it can IMPACT YOUR FERTILITY
You’d be astonished by how much work is involved in the menstrual cycle and conception. Constant dynamic changes are controlled by a delicate interplay of hormonal shifts orchestrated by the endocrine system. Its chief goals involve maturing a healthy oocyte, releasing it via ovulation so it can be fertilized, growing a thick and rich endometrial lining, and producing enough progesterone to allow the embryo to grow into a healthy fetus.
Both ample melatonin production and regular circadian rhythms are conducive to successful reproduction. Research(1) shows that surges in luteinizing hormone, which is required to release the mature egg for ovulation, relies on a feedback mechanism from the SCN, and disruptions to circadian rhythms result in deficits in ovulation and overall fertility(2).
Additionally, deficiency of melatonin plays a role in Polycystic Ovarian Syndrome (PCOS), which affects 1 in every 10 US women of childbearing age(3), and represents 80% of anovulatory fertility cases. High levels of melatonin in the ovarian follicle fluid is critical for ovulation, growth of follicles, and the quality of oocytes. The reduced level of melatonin in follicular fluid of women with PCOS may contribute to decreased egg quality and anovulatory cycles.
A recent study performed on women with PCOS who were IVF candidates showed that co-supplementation of melatonin and myo-inositol significantly improved embryo and egg quality compared with those given myo-inositol alone(4). The combination significantly improved pregnancy outcomes in women who failed to conceive in prior IVF cycles due to issues with the quality of the oocyte, exhibiting itself as a key factor in reproductive health.
it can lead to early pubarche and menarche
Children’s eyes absorb more blue light than adults’ eyes do from digital device screens. With increased blue light absorption, especially at night when many children are playing with their tablets before bed, melatonin production is substantially dulled. Low levels of melatonin in children are linked to initiating puberty and menarche at a younger age than normal(5,6), which could be an overlooked contributing factor to the rise of precocious puberty.
While the amount of time children spend indoors and on electronic devices increases, they’re exposed to less natural sunlight as a result. Exposure of our skin to sunlight is necessary for vitamin D production, which regulates multiple biological processes and is a key factor in healthy endocrine and immune function. Studies show that girls with precocious puberty have significantly lower serum vitamin D levels than those who begin puberty at normal ages (10-14 years) and deficiency may be associated with precocious puberty(7,8).
It’s evident that a healthy circadian rhythm with adequate production of melatonin is a significant factor in overall health and maintaining proper endocrine function. While we’re all humans living in the 21st century, it’s doubtful that we can forgo digital devices and technology altogether. Nor would I want you to. The key is minimizing your exposure with a few tricks I’ve listed below, and to gently coax your body to get on a sleep-wake cycle that is more aligned with the rhythms of the earth.
How to Get Your Circadian Rhythm Back on Track
morning sun exposure
Get Outside! – One of the root causes of dysregulation of our circadian rhythm is that we have limited daytime exposure to sunlight and increased nocturnal light exposure. By exposing your skin and eyes to sunlight for at least 20 minutes in the morning, your brain gets the message that it’s time to be awake.
This not only boosts your energy during the day, but since the SCN knows a good cycle when it sees it, it will help you out at night by sending signals to wind the body down when it should. This goes for children, too. A Japanese study showed that children exposed to sunlight for 30-60 minutes on their way to kindergarten showed more distinctive effects of shifting them to “morning types”(9). This was also influenced by feeding them protein with breakfast, which leads me to my next point.
eat protein
Make sure you are getting an optimal amount of daily protein in your diet. Protein provides you with the amino acid tryptophan, which is a building block of melatonin. Without sufficient amounts of protein, our body simply cannot produce enough melatonin.
minimize exposure to artificial blue light
While we should really make an effort to take time away from screens and devices, I’m not here to lecture you on this. So here are some ways to stay connected, but to minimize the negative impacts exposure to artificial blue light has on your health.
Utilize apps that sync the spectrum of light emitted from your devices with the rhythms of the sun
NightShift on Apple devices and getf.lux for computers is a great place to start. You can set them to start dimming and adjusting to a warmer hue at later hours, which minimizes the amount of blue light that you’re exposed to while on your device.
Try an adhesive orange screen for your TV
This has been life-changing for me. I’m a TV girl. At the end of the day, I love to turn a show on to unwind. The problem is, it’s a HUGE source of blue light, and I was exposing myself right before bed (exactly when you don’t want to be exposed). As a result, my sleep was being severely impacted. Since I often lay down and drift off with the TV on, I couldn’t wear blue-light blocking glasses, so I needed something else. I found this clear vinyl screen that you place over TV, and it gets rid of all the blue light. Yes, things will have an orange tint, but I don’t even notice it. It’s by far the best thing I’ve purchased for sleep, and it made a difference in the quality of rest without sacrificing what makes me happy.
Blue light-blocking glasses
Blue light-blocking glasses are an easy, surefire way to minimize exposure to blue light from screens and fluorescent lights in your office environment, grocery stores, and late-night flights. When I first started practicing these strategies years ago, everyone thought I was crazy as the girl walking around with hideous orange goggle-like glasses. You’re spoiled nowadays, as these are available in very stylish frames with clear lenses that can be fit to your prescription. This gives anyone with 20/20 vision the excuse to wear accessory glasses they’ve always wanted, too. Two great brands to try are Felix Gray and True Dark (P.S. I am not affiliated with any of these brands – I just know they work well).
be consistent
Commit to a consistent bed and wake time. The disparity between weekday and weekend sleep schedules creates something called "social jetlag," which has been linked to several health issues(10). With social jetlag, our body is constantly trying to adjust back and forth, dysregulating a steady circadian rhythm and negatively impacting sleep.
exercise
Exercise increases serotonin production. You need serotonin to make melatonin, which as you’ve learned is an important sleep hormone. Exercise also reduces inflammation, when done correctly, which garners better sleep. It also burns a lot of energy, and some of this extra energy keeps people up at night.
To summarize, your circadian rhythm plays an integral role in your overall health, but specifically your endocrine system and hormonal picture. If you’re experiencing symptoms of hormonal imbalance, such as thyroid issues, sudden weight gain or inability to lose weight despite doing “all the things,” acne, fertility issues, severe PMS, and irregular menstrual cycles to name a few, working on regulating your circadian rhythm is a great foundational start that could make a significant difference.
Too much exposure to artificial blue light – altogether and especially at night - is a direct contributor to this dysfunction. There are many ways to minimize blue light exposure, boost melatonin production, and establish a healthy circadian rhythm. Try three of the suggestions in this article, commit to them for a minimum of three months, and see how you feel.
And, look around if you’re ever on Amtrak’s Northeast Regional line. If you see a girl wearing blue light-blocking glasses, it’s probably me.