A little nighttime reading

How does light affect sleep? Get better sleep with a pitch black room.

The next time you turn out the light at night, take a look around and notice how dark your bedroom really is. Is there a sliver of moonlight glistening through the blinds? An alarm clock dimly lit on the nightstand? Or a peek of hallway light shining through the door crack? Exposure to light during the night -- even the teensy-tiniest bit -- can disrupt your sleep and may even affect your long-term health.

Our bodies evolved to sleep in darkness at night. Have you ever noticed times when you’ve slept in a pitch-black place -- maybe a hotel room with blackout curtains or camping in the wilderness -- and had the best sleep of your life? At a very basic level, our body's circadian rhythm (or "body clock") is tied to sunlight, which controls the sleep/wake cycle. When there is no sunlight, it’s time to sleep.

Today's culture challenges our body's natural rhythms
Yet, in today’s modern society, we're surrounded by artificial light most of the evening. Many artificial light sources emit blue wavelengths (or "blue light"), which inhibit sleep-promoting neurons and instead activate arousal neurons. This is true for most digital devices -- like smartphones, tablets and laptops -- as well as flat-screen TVs. Which is why sleep specialists advise not using these devices for at least an hour before bedtime.

Keep in mind that blue light is essential to regulating your circadian rhythm for healthy sleep at night, and it’s beneficial to get exposure from the sun during daytime hours.

Another reason why digital devices are bad for sleep is because the light their screens emit suppresses melatonin production. Melatonin is light-sensitive and secreted in the dark. This hormone is a powerful antioxidant, which also reduces estrogen production.

Too much estrogen is linked to increased risk of breast cancer. Blind women apparently have 50% less breast cancer than sighted women. This is in part attributed to the fact that blind women live in darkness 24/7 and sleep more on average, encouraging higher production of melatonin.

Even the teensy-tiniest bit of light can affect us
Even after you turn out the lights, it’s the sneaky light sources peeping through the window or hallway that could be worst of all. Ideally, you want a pitch-black room. Even small amounts of light pollution can keep your pineal gland (a small endocrine gland in your brain) from producing melatonin. Israeli researchers linked higher breast cancer incidence to neighborhoods with the brightest nighttime lighting levels. The women with the highest "bedroom light intensity" had a 22% higher risk of breast cancer.

Sleep disruption can also keep your body from maintaining healthy cortisol levels. Cortisol is key because it regulates your immune system while releasing cells that thwart cancer.

So how do I banish light from the bedroom?

Light from a multitude of sources can pervade our bedrooms. A common way to keep light from disrupting your sleep is to wear a sleep mask. But most masks get hot, are irritating or easily fall off during the night. So how do you keep light out without the hassle? Here are some convenient options:

Install blackout curtains.
If you’re looking for a surefire way to create a pitch-black bedroom, blackout curtains are a must. Most stores that sell curtains and drapes sell blackout options that efficiently block out virtually all light from windows. Even better, these curtains save on energy costs and reduce outside noise.

Cover your alarm clock and other device LEDs.
If you use an alarm clock on a nightstand that emits a glow during the night, cover it up with a small towel or cloth, or turn it around to face the wall. For a more permanent solution, replace the alarm with one whose light is dimmable or non-existent. Choose alarm clocks illuminated with red light if possible. Other colors generate light in the blue spectrum.

Also, sweep the bedroom for any devices that have brightly-lit LEDs. You can cover the LEDs up with electrical tape, or move the device to where the light is less disruptive.

Put away your smartphone.
First of all, we do not recommend sleeping with your smartphone next to your bed in close proximity if you can help it, as evidence shows this affects brain activity and disturbs your sleep. Even if your smartphone is laying across the room, your sleep can be disrupted anytime your phone lights up from incoming calls, texts or notifications. If you must keep your phone in the bedroom, rest your phone on the table with the screen side down.

Use digital device screen adaptive software.
If you just can’t stop using electronic devices at least an hour before bedtime, use screen software that reduces the amount of blue light emitted during the evening. Apple products have built-in Night Shift Mode, or you can download Twilight for Android devices and f.lux software for your laptop. You may also reduce the effects of screens on melatonin production by turning down the screen brightness and holding the device at least 12 inches away from your face.

Use nightlights in hallways and bathrooms.
If you need to hit the bathroom in the middle of the night, turning on the full bathroom lights can keep you up afterward. Instead, use dim nightlights along the path to the bathroom or in the bathroom itself to guide your way without giving you the full-on wakeup call.  

Looking for other helpful ways to get better sleep? Check out Slumbr’s list of essential sleep tips everyone should know.



Photo credit: © Can Stock Photo