BENGALURU: Reading e-books an hour before going to sleep increases alertness and causes other biological changes in the body that lead to sleep disruption and sleepiness in the mornings, a recent study has found.
With computer screens switched on during nights and glow-in-the-dark clocks in homes, finding a dark room to sleep in may be a tad difficult.
A group of scientists associated with the Harvard Medical School, Boston, Massachusetts, USA, studied the habits of 1,508 Americans and found that more than 90 per cent of them used some type of electronic gadget at least a few nights a week an hour before bedtime. Earlier studies have shown that blue light (short-wavelength enriched light) from electronic devices suppresses melatonin harmone, thus interrupting the body’s natural circadian rhythm and heightening awareness. Melatonin plays a role in sleep cycles.
The Harvard scientists compared the biological effects of reading an e-book on a light-emitting device (LE-eBook) with reading a printed book before bedtime. Participants reading an LE-eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion and reduced morning alertness.
In the past 50 years, there has been a decline in average sleep duration and quality, with adverse consequences on general health. Evidence from countries around the world shows the negative impact of such technology on sleep.
It has been shown experimentally that exposure to artificial light produces alerting effects, suppresses melatonin and disturbs the biological clock, the study says. A few other reports too have shown that these devices suppress melatonin levels.