For as long as I can remember people have told me you need 7-8 hours of sleep over night to maintain a healthy life style.Public Health authorities have always warned us that technology before bed can mess up our natural sleeping patterns causing sleep deprivation. However, a new study is contradicting this idea.

Americans now a days gets 2-3 less hours of sleep than those during the industrial revolution.  The study found that Americans get the same amount of sleep as the 3 different hunter-gather societies did before electricity. The Hadza and San tribes in Africa, and the Tsimané people in South America are even said to have gotten even less sleep than many Americans. According to this new study, the hunter-gathers were relatively fit and healthy despite the small amount of sleep they got. Previous research shows that their daily energy levels are the same as most Americans. This new information goes against everything we were taught in order to live a healthy life-style. Many studies suggest that constant sleep pattern of less than 7 hours of sleep can lead to obesity and chronic disease.

Jerome Siegel a professor of psychiatry at U.C.L.A. says that, “the prevailing notion in sleep medicine is that humans evolved to go to bed when the sun goes down, and that by and large we stay up much later than we should because we are flooded with artificial light” (New York Times).   However, Dr. Siegel and his colleagues found no evidence of this. The hunter-gathers the studied stayed up 3-4 hours after the sun went down with little light exposure and then woke up an hour before sun-rise. They slept 6.5 hours on average.

John Peever, a sleep expert,  believes that this finding with change the field of sleep. “It’s difficult to envision how we can claim that Western society is highly sleep deprived if these groups that live without all these modern distractions and pressing schedules sleep less or about the same amount as the average Joe does here in North America” (New York Times).

Nathaniel Watson, the president of the American Academy of Sleep Medicine, said that the recommended 7-8 hours of sleep a night were based on a review of 5,000 studies that assessed sleep and disease in humans. Most of these studies were based on self-reporting, which tends to be overestimated because people report the overall amount of time they spent in bed, not the amount of actual sleep. Hunter-gathers were said to be in bed for roughly 7-8.5 hours, which is consistent with recommendations.

However, in the end Dr. Watson says that it is, “Really it’s just the amount that allows people to wake up feeling refreshed and alert.” Jim Horne, the director of the Sleep Research Center at Loughborough University in England says that sleep quality is much more important than quantity.

One of the groups the researchers decided to track were the Hadza people located in northern Tanzania, the Tsimané located in Bolivia, and the San located in the Kalahari. They attached wristwatchlike devices to track their sleeping patterns. The found that roughly they slept the same amount each night and the three groups rarely took naps and did not sleep in two separate intervals, meaning they slept through the night. They found that their sleeping patterns were remarkable close to each other despite the distances between them. Dr. Siegel  “’The fact that we see very similar sleep times gives me great confidence that this is how all of our ancestors slept.’”

In conclusion, we don’t necessarily need 7-8 hours of sleep. The thing that matters the most is the quality of our sleep. Though hunter-gathers and Americans live very different lift-styles they still get similar amounts of sleep. I think that it is interesting that hunter-gathers only have a 2% insomniac population versus the American 20-30% even though they have similar sleeping patterns. This shows that there are confounding variables involved in these results, one of them being that hunter-gathers do not have artificial lighting to cause problematic sleeping problems for many Americans. There are other factors on how well you sleep such as your diet and exercise. Hunter-gathers most likely have a healthier diet than Americans because they are not exposed to processed food. They also are moving around a lot because they work in an agricultural atmosphere. Both are very different from the average American life-style.

Here is a video summarizing the findings