One major complaint in society is that modern lifestyle luxuries, such as artificial lighting and electronic devices, have reduced sleep duration from its “natural” levels and caused a disruption in sleep patterns. However, according to a recent study published in the journal Current Biology, researchers suggest that people who live away from city lifestyles may sleep even less than those in the city.
Evidence shows that three ancient groups of human hunter-gatherer societies who live traditional lifestyles in various parts of the world (i.e. without electricity, heating, or cooling systems) sleep slightly under 6.5 hours on average each night. Since they don’t take regular naps, nor fall asleep as soon as it’s dark outside, their sleep habits aren’t that different from those in the industrialized world (with the exception that they wake up before the sun rises).
To further investigate how people slept before the modern era, researchers analyzed three traditional human hunter-gatherer societies: the San of Namibia, the Tsimane of Bolivia, and the Hadza of Tanzania.
The research team, led by Jerome Siegel of the University of California-Los Angeles, and his colleagues recorded the sleeping habits of 94 individuals and collected data representing 1,165 days in total.
Siegel and his colleagues found that all three groups, despite coming from different environments, all showed a similar sleep pattern. Researchers believe that they represent basic human sleep patterns characteristic of the human species pre-modern era.
The group sleep time averaged between 5.7 to 7.1 hours with 6.9 to 8.5 hours between sleep periods. These amounts are at the lower end of sleep-duration spectrum reported in industrial societies.
“The short sleep in these populations challenges the belief that sleep has been greatly reduced in the ‘modern’ world. This has important implications for the idea that we need to take sleeping pills because sleep has been reduced from its ‘natural level’ by the widespread use of electricity, TV, the Internet, and so on.”
The team believes that temperature could be linked with sleep cycles, more so than light. The ancient groups went to sleep as the temperature fell and slept through the coldest parts of the night, which suggests that the daily cycle of temperature changes may help regulate sleep.
Researchers also discovered one crucial difference between people living in the “modern” world and the hunter-gatherers—very few hunter-gatherers suffered from insomnia, which is a common issue in the U.S., affecting over 20% of the population.
The research team suggests that mimicking certain aspects of the natural environment lifestyle experienced by these groups might help treat certain modern sleep disorders.
Complaints about sleep disorders have been documented since the 1980s and have been linked to several health issues, including mood disorders and obesity.
Sources for Today’s Article:
Brazier, Y., “Could 6.5 hours of sleep be all we need?” Medical News Today web site, October 15, 2015; http://www.medicalnewstoday.com/articles/300962.php.