Obviously, the words you’re reading right now appear on a lit screen. There’s nothing wrong with that, of course…unless you’re reading this just before bedtime.
Harvard Medical School researchers recently mounted a study to see how reading from a lit screen at bedtime affects sleep.
Now, you might think you know where this is going — and you’re not wrong. But it goes surprisingly deep, and it has implications for all of us.
Fortunately, there’s a simple solution.
More on that in a moment. First let’s take a closer look at the surprising effect a simple screen can have on your attempt to get a good night’s rest.
Not so easy on the eye
In the Harvard study, researchers asked a half-dozen healthy young adults to read from an ebook for four hours before bedtime every night. Another half-dozen were asked to do the same with printed books
After two weeks of nighttime reading, followed by a battery of tests and questionnaires, researchers found that the nightly ebook habit had these powerful effects…
- Prolongs the amount of time it takes to fall asleep
- Delays the circadian clock
- Suppresses melatonin
- Delays onset REM sleep
- Reduces the amount of REM sleep
- Reduces alertness the next morning
The wide range of these results is troubling, especially given that 90 percent of adults in the U.S. say they often spend some time on an electronic device at bedtime.
It’s hardly any wonder why sleep quality and time spent sleeping have both steadily dropped over the past half-century.
Of course, ebooks, smartphones, and other devices are just part of the problem. Modern living has a way of throwing wave upon wave of sensory disruptions at us. And these disruptions affect all of us, whether or not you look at your phone or tablet before bed…
The sunrise/sunset hormone
In the Harvard results, the detail about melatonin suppression stands out because your sleep quality depends on the normal function of this hormone. In fact, most of the sleep problems in the study, maybe even all of them, were likely triggered by melatonin suppression.
Melatonin plays an important role in circadian rhythm, which is your body’s natural sleep/wake cycle. It’s controlled by nerve cells in the hypothalamus region of your brain. These cells follow the cues of a light-sensitive protein in the retinas of your eyes.
When the protein is exposed to light, it sends a message to the hypothalamus to lower or cut off melatonin production. When darkness falls, the message changes and the hypothalamus prompts your pineal gland to begin generating melatonin until it reaches a level that makes you sleepy.
So it’s no wonder that staring at a lit screen just before bedtime would suppress melatonin, reduce quality of sleep, and cause fatigue the next day.(Melatonin also has cancer preventive effects, so any suppression of this hormone is doubly risky.)
Going gentle into a disruptive night
In Dr. Fred Pescatore’s Perfect Sleep Protocol, he discusses a few different natural sleep aids, but he admits one in particular stands out among the rest: melatonin.
Not only do melatonin supplements have “benefits beyond the bedroom,” as Dr. Pescatore says, but they have the remarkable ability to help you sleep through a variety of potential sleep disruptions.
For instance, a hospital intensive care unit is a notoriously difficult environment to sleep in. So in a recent study, researchers at Capital Medical University in Beijing, China, tested a melatonin supplement in conditions that simulated an ICU environment with bright lights and noise.
Here’s Dr. Pescatore’s description of the study: “Researchers recruited 40 healthy participants to study the effects of simulated ICU conditions (where bright light and noise are common) on sleep patterns. After determining baselines for all the participants, the researchers divided them into four groups.
“The first group received no sleep aid. Participants in the second group were provided with eye masks and earplugs. The third group took 1 mg of melatonin before going to bed. Those in the final group were given a placebo.
“The researchers found that all sleep patterns were disturbed by the simulated ICU environment. But those who took melatonin had fewer awakenings during the night than any of the other groups — even fewer than the eye mask and earplugs group.
“The participants taking melatonin also reported better-quality sleep, with reported lower anxiety levels and increased REM (rapid eye movement), which refreshes and stimulates the parts of the brain used for learning.”
Dr. Pescatore believes the study volunteers would have done even better with a much larger dose of melatonin, which would still have been quite safe.
He says, “I recommend a range of 3 to 5 mg of melatonin at bedtime for most people. You can start with 1 mg, especially if you’re taking it with other supplements, and gradually increase as needed. Just be sure not to exceed 15 mg per day.”
And needless to say, a melatonin supplement will work much better if it doesn’t have to fight against unnatural late night light exposure. Most sleep experts recommend that we turn off all our screens a couple of hours before bedtime.
Give your eyes and brain a break, and sleep is likely to come much faster and will be more restful.
Ebooks at night won’t help you sleep tight, US study finds
December 23, 2014