It’s Not Just Pre-Bed Screen Time that Causes Sleep Loss

The ideal 7-9 hours of nightly sleep is a recent discovery.  Historical data suggests humans have been struggling to get a good amount of sleep long before the invention of electronic devices.  Broken sleep was normal in industrial times, according to research from Virginia Tech’s sleep historian, Roger Ekirch.

Several studies have shown that screen time before bed can interrupt sleep patterns; however, recent research shows that even without television, laptops, or other electronic gadgets, people are getting less sleep than recommended by sleep experts.

A study out of Duke University looked at the sleep patterns of a Madagascar farming village without electricity or artificial lights.  Researchers found that these farmers actually get poorer, shorter sleep than those in Europe or the U.S.; however, of important note is that these villagers make up for lost sleep by having a regular sleep routine.

Findings were published in the American Journal of Human Biology. 

The addition of electronics and artificial light use before bed has greatly contributed to the decline of American sleep quality.  These bright lights and active screens make it near impossible for us to stay on course with a 24-hour synched biological clock.  Specifically, our brains are sensitive to the “blue” light that comes from a TV, computer, LED bulb, smartphone, or a number of other devices.  This light signals the brain to slow down its melatonin production, which is the hormone necessary for sleep.

Charles Nunn, a Duke professor, and his colleagues went to a small Madagascar village to try to gain a better understanding of human sleep patterns, especially since these people live without electricity.  This area is one of the few slivers of Earth that has little to no light pollution.

More than a billion people around the world live without electricity.  Rather than flipping a switch to turn on a light at night, villagers and those without electricity spend their time in relative darkness, with the use of oil lamps, the soft glow of cooking fires, or the light of the moon.

Scientists analyzed the nighttime and day naptime sleep patterns of 21 villagers aged 19 to 59 years.

Data was collected using watch devices on the participants, which had built-in motion and light sensors that track any form of movement and light exposure in real-time.  This was done for 292 nights.  Nine of the participants had a polysomnogram performed to see how restful and deep their sleep was.

Findings showed that these villagers got less sleep than those in Europe or America, even without the distraction of gadgets and artificial light.

However, notably, villagers had a more patterned sleep routine.  They generally went to bed around two hours after sunset, approximately 7:30 p.m.  They awoke about an hour before sunrise, around 5:30 a.m.; however, data showed that only 6.5 of those hours were spent sleeping.

Sleep was noted to be light and fragmented.  Houses were made of bamboo walls and thatched or tin roofs that did not keep out noise, and there were nightly parties, roosters, crying children, and barking dogs, making for a hectic sleep environment.

There were frequent nighttime awakenings, often to use the bathroom, which caused them to stay up for another hour or two before falling back to sleep.  Participants spent less time in deeper stages of sleep, especially the dream state called REM.  There was no complaining, however.  About 60% of participants reported being satisfied with their sleep.

The loss of sleep is compensated with daytime naps, usually up to an hour, which is twice as long as catnaps taken by many Westerners, Samson reported.  Researchers noted that the villagers’ sleep habits and bedtime routines were much more consistent than those in Western cultures were.  Even with the use of an LED lantern in the village for one week, participants still had virtually the same sleep and wake times.

This indicates that a regular bedtime routine and sleep schedule is important for a good night’s sleep.

Duke researchers will continue studying sleep patterns in urban populations around the world, with the goal being to build a better understanding of traditional sleep on a global level.


Rachael Herman is a professional writer with an extensive background in medical writing, research, and language development. Her hobbies include reading, traveling, and cooking.

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