Banish the blue light bedtime brigade
FOR the tech-obsessed who use their smartphones, laptops and tablets right before bedtime, a new study suggests inexpensive amber-tinted glasses might guarantee sound slumber.
The glasses block the blue-wavelength light emitted from many hi-tech devices. That light suppresses the brain’s production of melatonin, a hormone that regulates sleep and wake cycles.
In the study, researchers found that adults diagnosed with insomnia got about 30 minutes more sleep when wearing wrap-around amber lenses for two hours before bedtime.
“We suspected blue-light exposure before bedtime might contribute to sleep difficulties or worsen sleep problems in individuals who already had difficulties, so we were not surprised there was an improvement in sleep quality,” said study author Ari Shechter.
He is an assistant professor of medical sciences at Columbia University Medical Centre in New York City.
“These glasses are widely available,” added Shechter, who has no financial stake in the findings.
Insomnia symptoms such as difficulty falling or staying asleep, frequent awakening or disturbed sleep occur in as many as a third to half of adults, according to background information in the study.
In addition, an estimated 90% of Americans use light-emitting electronic devices – such as tablets, smartphones and computers – in the hour before bedtime, despite the sleep-inhibiting effects of this blue-light exposure.
In the new study, 14 adults with chronic insomnia wore wrap-around, amber-tinted glasses or clear placebo glasses for two hours before bedtime for seven consecutive nights. Four weeks later, participants repeated the process with the other set of glasses.
In addition to getting about half an hour more sleep on nights after wearing the amber lenses, participants also reported better-quality sleep and an overall reduction in their insomnia symptoms.
A slight reduction in the time it took amber lens-wearing participants to fall asleep was noted, though it wasn’t statistically significant. “It is possible the intervention would be more effective in speeding up time to fall asleep in individuals who have difficulty falling asleep as their chief sleep complaint,” Shechter said.
Many smartphone screens can be adjusted to emit amber instead of blue light, which would help reduce insomnia symptoms in those affected. Blue-wavelength light is also emitted from many light bulbs and LED light sources increasingly used in homes because of their energy efficiency and cost-effectiveness, he noted.
“Now more than ever, we are exposing ourselves to high amounts of blue-wavelength light before bedtime, which may contribute to or worsen sleep problems,” Shechter said.
“We believe this to be an important and timely study, as it describes a safe, affordable and easily implemented intervention for insomnia,” he added. Avoiding exposure to light fr
om light-emitting devices before sleep would be the best approach, but using other techniques to block the blue light can help if use of the devices is going to continue,” said Shechter.
Dr Raman Malhotra, a spokesperson for the American Academy of Sleep Medicine, wasn’t involved in the research but agreed with Shechter that the research should be replicated in larger numbers of patients with insomnia, possibly over longer periods.
Malhotra said some doctors were already recommending patients with insomnia wear amber-tinted glasses before bedtime, reasoning there was little to lose.
“I look at cost or risk compared to possible benefit, and in this case I feel cost and harm are minimal compared to benefits in patients’ sleep,” said Malhotra, an associate professor of neurology at the Washington University Sleep Medicine Centre in St Louis.
“Many people have trouble sleeping because of the light from their devices, and this is a reasonable thing to use,” he added.
The study is scheduled for publication in the January issue of the Journal of Psychiatric Research. – New York Times
Blue-light exposure before bedtime, from phones or computer screens, may hamper sleep.
A slight reduction in the time it took amber lens-wearing participants to fall asleep was noted, though it wasn’t statistically significant.