According to the results of a new study conducted by a research team from the University of Colorado Boulder, in the United States, subjects who spent one week camping in the Rocky Mountains, exposed exclusively to natural light, managed to reset and sync their circadian clocks to the sunrise and sunset. The study was recently published in the journal Current Biology. The research team investigated a number of 8 subjects, who were picked regardless of their sleeping habits during their day-to-day life.
According to the research team, electric light affects our internal circadian clocks. Our circadian clock is the process through which our brain tells our bodies when to prepare for sleep and when to wake up. In order to quantify the effects that electric light has on people, the research team, led by professor Wright, monitored the 8 subjects over a week of their normal day-to-day lives. Each subject received a wrist monitor that measured the intensity of the light to which subjects were exposed, while also recording the amount of time subjects were exposed to light, and at what hours.
At the end of the first week of study, all of the data was recorded and introduced into a database. Researchers further investigated the hormone known as melatonin. Melatonin is a hormone released by the pineal gland that acts as a signal for the circadian clock. The levels of melatonin rise when the biological night begins and decrease when our biological day begins.
The same parameters were once again monitored during a second week of investigations. However, instead of their normal day-to-day lives, the subjects went camping in the Rocky Mountains. During the camping week, all of the 8 subjects were exposed exclusively to natural sunlight and the glow of fire from a campfire. No flashlights or other electronic devices were allowed during the one week period. The results of the study revealed that the average biological night started 2 hours earlier when the subjects were exposed only to natural light. Furthermore, the subjects also woke up earlier than their natural start of the biological day.
Researchers affirm that in the days following the camping trip, the study subjects experienced a more natural circadian rhythm, with the biological nighttime starting at sunset and ending close to sunrise. According to professor Wright, people who live in the modern urban world are very different from each other. Some like to stay up late, others like to wake up early. He reports that the results of the study show that these differences can be decreased dramatically if the circadian clocks are reset.
The study, demonstrating the, also shows possible solutions for individuals with strong effect of natural light for each individual’s circadian clock bad sleeping habits. As an example, the results show that individuals with sleeping habits that involve staying up late at night might also experience difficulties in feeling alert early in the morning. This could be linked to the fact that the melatonin levels indicate that they woke up during their biological night-times, instead of being in their biological day-times.
Wright also suggests that in order to correct their own circadian clock, people should consider more light exposure during mornings and during midday. Furthermore, diminishing the amount of exposure to electric lights at night, such as TV, laptop screens, and other personal devices, can improve the circadian clocks and get them attuned to the solar day.