Did you know that too much sleep can be harmful? According to the Mayo Clinic, oversleeping on a regular basis can lead to depression, weight gain and a variety of other health problems.

Are you sleeping too much?

An new study from U.C.L.A. suggests LESS than the usual 8 for adults.

It also suggests that good sleep may not be connected to light and darkness, but temperature shifts instead!

Jerome Siegel, professor of psychiatry at the Semel Institute of Neuroscience and Human Behavior at U.C.L.A. is the lead author of the new study.

Jim Horne, the director of the Sleep Research Center at Loughborough University in England, called the new study “excellent and very timely,” and he said it suggests that sleep quality is much more important than quantity.

However, the American Academy of Sleep Medicine and the Sleep Research Society’s recommendations for 2015 suggest as usual that adults should sleep seven or more hours on a regular basis. And if they don’t they should pay a visit to their health care provider: “Sleeping less than seven hours per night on a regular basis is associated with adverse health outcomes, including weight gain and obesity, diabetes, hypertension, heart disease and stroke, depression and increased risk of death.” But is that true?

The new study says that we may not need as much sleep as we think!
Quality is more important than quantity!

Dr. Siegel’s team studied indigenous groups, hunter-gatherers, the Tsimané, the Hadza and the San, who live in different parts of the world. 

Members of the various tribes were fitted with small wristwatch like devices that tracked their sleep patterns and their exposure to light across the seasons. “The fact that we see very similar sleep times gives me great confidence that this is how all of our ancestors slept,” said Dr. Siegel.

Members of those groups did not go sleep at sunset and they did not wake up at sunrise. Their sleep did not seem to be problematic.

Actually, “chronic insomnia, which affects 20 percent to 30 percent of Americans, occurred in just 2 percent of the hunter-gatherers. The San and the Tsimané did not even have a word for it in their languages.”

The prevailing notion in sleep medicine is that our sleeping patterns follow the light of the sun – go to bed when the sun goes down and get up with the sun rise. But we all have electricity in our homes and we switch on the light!

One hypothesis for not getting enough sleep is that after the invention of the electric light bulb in the late 1800s, and all the artificially lit environments that followed, messed up our sleep.

We hear about the light on our reading tablets keeping us up longer, the tv screen, the artificial lights at home being responsible for the body’s biological clock being off – interfering with sleep.

But maybe sleep is more connected to temperature rising and dropping and not only to light.     

Dr. Siegel said that ambient temperature seemed to be a major factor in their sleep study.

The researchers noticed that light exposure did not have much influence on sleep patterns. They almost always fell asleep as temperatures began to fall at night, and they would wake up right as the temperatures were rising again.

“This suggests that humans may have evolved to sleep during the coldest hours of the day, perhaps as a way to conserve energy. If falling temperatures at night are a signal to our bodies that it is an ideal time to go to sleep, then that could be one reason chronic insomnia is so prevalent in industrialized societies.” Dr. Siegel said.

What we need to keep in mind is that:

  1. Sleeping allows the body to rest and the brain to recharge after each day. Although we don’t really know exactly what happens in our brain when we sleep we know you have slept well when we wake up refreshed.
  2. The number of sleep hours we need varies from person to person, even within a particular age group.
  3. Conduct your own study on days with some exercise, good food, and no medications or other substances. 
      • How many hours of sleep do you need to wake up refreshed?
      • Also evaluate your optimal room temperature to fall a stay asleep.
      • Pay attention to your bed covers. How breathable they are to allow for air to circulate.  Stick to 100% cotton sheets, wool or dawn and review your pillow and mattress choices. 

Good night!

P.S. If you want to read more on this study, follow the New York Times article: “Do We Really Need to Sleep 7 Hours a Night?” By ANAHAD O’CONNOR  OCTOBER 15, 2015

P.P.S. Also, PBS has a video with Hari Sreenivasan, PBS NewsHour reporter, speaking with the U.C.L.A. scientist Jerome Siegel about whether modern man is sleep-deprived, Publish Date October 15, 2015.