Regular readers of this blog will know that I often talk about artificial light being a menace to sleep health.
Not only does the very existence of artificial light in the form of light bulbs encourage us to spend more time awake, the type of light emitted by the numerous gadgets and gizmos we have within arm's reach can suppress our body's natural release of melatonin.
Yet a new study suggests there's something far more important than reducing exposure to light when it comes to improving sleep: temperature.
The study in question originally set out to determine how much sleep our ancestors were getting compared to the average amount of sleep we get today.
(It concluded that we actually get more sleep now than our ancestors did).
However, the study also investigated the influence of light and temperature on sleep.
After studying three separate tribes in Tanzania, Namibia and Bolivia, researchers discovered that participants did not go to sleep as soon as the sun set.
In fact, they typically fell asleep more than three hours after sunset. The researchers attributed sleep onset with falling temperatures, arguing that sleep occurred as the air temperature fell. Once the ambient air temperature bottomed-out, participants began to wake up.
With the invention of central heating and thermostats that help us live with a consistent temperature year-round, regardless of the time of day, we are far less exposed to changing temperatures compared to our ancestors.
The researchers of this study argue that the daily cycle of temperature change could be a strong regulator of sleep - so our modern-day lack of exposure to temperature change could be a contributor to sleep problems.
Perhaps we shouldn't be so hard on artifical light as an insomnia cause, then - maybe we need to redirect our scorn towards central heating and thermostats!
Source: Current Biology
Last updated: October 16, 2015