According to a new study published in the Proceedings of the National Academy of Sciences, using electronic devices such as tablets and smartphones before bedtime can alter a person’s sleep pattern with serious repercussions on one’s health.
The experiment was conducted at Brigham and Women’s Hospital in Boston by a team of researchers from Penn University. Twelve people took part in the 14-day study. Two groups were nominated. One would read for five consecutive nights from an iPad, the other one would read printed books. After a week, the groups switched.
The reading material could be chosen by every participant as long as it was considered “leisure” and contained only text. The reading sessions lasted 4 hours from 6 p.m. to 10 p.m. after which the person would sleep until 6 a.m.
A series of tests were conducted. The presence of melatonin, a hormone the body produces especially in the evening and helps induce sleepiness was determined through blood tests, polysomnography, a method used to document brain waves, heart rate, breathing and eye movements was used to calculate the time needed for the individual to fall asleep, the number of hours the person managed to sleep and the duration of each sleep stage.
They used the Karolinska Sleepiness Scale to determine each person’s subjective sleepiness level. The time needed for the person to become alert the following morning was also evaluated.
The results showed that the iPads readers presented lower melatonin levels in comparison to those who read from printed books. Furthermore, the iPad users needed 10 minutes longer to fall asleep and their REM (rapid-eye-movement) sleep period was shorter compared to the other group. They also reported feeling sleepier and needed more time to become alert the following morning.
So how do electronic devices like iPads affect out sleep? Anne-Marie Chang, assistant professor of biobehavioral health at Penn University and co-author of the study explained:
“Electronic devices emit a short-wavelength-enriched light, which has a higher concentration of blue light – with a peak around 450 nm – than natural light. This is different from natural light in composition, having a greater impact on sleep and circadian rhythms.”
She added that being sleep deprived has greater effects in real-world situations, in contrast to the “controlled environment” used by researchers. Furthermore, there are studies that associate persistent low levels of melatonin to a higher risk of prostate and breast cancer. In addition to this, prolonged sleep deprivation has been linked to obesity and diabetes.
Luckily there are some devices, such as the Kindle e-reader that do not emit light and of course, there is always the option of printed books.
Image Source: iPadMango