Do You Take Your E-Reader to Bed?
Feeling groggy in the morning? If you're reading yourself to sleep with a light-emitting electronic device, you may be sabotaging your sleep.
Good-quality sleep is vital for healthy aging. Poor sleep endangers our health, and puts us at higher risk of falls and other accidents. In late 2014, the American Academy of Neurology even announced that poor sleep is a risk factor for dementia.
Yet as we grow older, refreshing slumber often eludes us. Pain, depression, incontinence, inactivity, medications, family caregiver duties and even natural changes in our sleep cycle can make it hard to go to sleep and stay asleep. A poll of Caring Right at Home readers showed that only one-fourth are getting the recommended eight hours per night!
And these days, we face a new challenge to good-quality sleep. In 2011, the National Sleep Foundation reported that computers, smartphones, texting, video games and even watching TV not only tempt us to stay up later, but also contribute to lower-quality sleep once we finally hit the sack.
Said study author Charles Czeisler, Ph.D., M.D., of Harvard Medical School and Brigham and Women's Hospital, "Artificial light exposure between dusk and the time we go to bed at night suppresses release of the sleep-promoting hormone melatonin, enhances alertness and shifts circadian rhythms to a later hour—making it more difficult to fall asleep." (Circadian rhythms are the body's natural sleep/wake cycle.)
Czeisler added, "This study reveals that light-emitting screens are in heavy use within the pivotal hour before sleep. Invasion of such alerting technologies into the bedroom may contribute to the high proportion of respondents who reported that they routinely get less sleep than they need."
And the problem has expanded: Not only are more of us staying up later using our devices, but we also are taking them to bed with us! It's a long tradition to "read ourselves to sleep." Though we sometimes report that a book was so exciting that we stayed up all night reading it, for the most part we drift off after a short time. Reading can be an effective way to transition into sleep for many people.
But now, more people are doing their bedtime reading on a backlit e-reader or tablet computer. And this, say sleep experts, could be a problem. When the light beams directly into our eyes, sleep comes more slowly and is less refreshing. According to Penn State University professor Anne-Marie Chang, "Electronic devices emit light that is short-wavelength-enriched light, which has a higher concentration of blue light than natural light. This is different from natural light in composition, having a greater impact on sleep or circadian rhythms."
Chang recently conducted an experiment at Brigham and Women's Hospital, where she is a neuroscientist in the Division of Sleep and Circadian Disorders. Under carefully monitored conditions in the hospital's sleep laboratory, a group of volunteers read a book before bed for five nights. Then, for the next five nights, they tucked into bed with an iPad. Chang's team compared the quality and duration of their sleep on the traditional book nights versus the iPad nights.
The researchers found that when reading with the iPad, participants took on average 10 minutes longer to fall asleep. Their sleep pattern also featured a significantly lower amount of restorative REM sleep. Said Chang, "Our most surprising finding was that individuals using the e-reader would be more tired and take longer to become alert the next morning. This has real consequences for daytime functioning."
It's important to note that this study focused on e-readers that emit light, not on those using the "e-paper" display that mimics the appearance of ink on paper. Experts believe those devices, for example, the original Kindle, do not have the same sleep-disturbing effect.
Chang said, "We live in a sleep-restricted society in general. It is important to further study the effects of using light-emitting devices, especially before bed, as they may have longer-term health consequences than we previously considered.
March 2-8 Is Sleep Awareness Week
The National Sleep Foundation, sponsor of this event, offers consumer advice about getting a good night's sleep, as well as information and updates on a wide variety of sleep problems. Read more about their Technology and Sleep poll here.