Lightbulb Study Illuminates Secrets to Good Night's Sleep
How often do you get a good night's sleep? Chances are, according to a 2009 poll by the National Sleep Foundation, not often enough. About one in four people gets only a few nights of good sleep a month.
Researchers from Case Western Reserve University, the Louis Stokes Cleveland VA Medical Center, Rensselaer Polytechnic Institute's Lighting Research Center, and GEConsumer and Industrial are trying to change that.
This spring, they conducted a small pilot study examining the effects of blue light on the sleep-wake cycles of Alzheimer's disease patients. "It's well known that people with dementia have trouble with sleeping," says Patricia A. Higgins, PhD, RN, a lead investigator on the study and an associate professor in Case Western Reserve's Frances Payne Bolton School of Nursing. Scientists are unsure why dementia patients have difficulty sleeping, though it may be a neurological issue, she says, adding that the idea is to provide these patients with dementia better stimulation during the day to keep them awake with fewer naps, which will help them sleep better during the night. Light therapy has been shown to be a safe, nonpharmacological treatment for sleep disorders.
"Light is a good stimulus for the circadian system, which regulates your sleep-wake cycles," says Thomas Hornick, MD, associate director of the VA's Geriatric Research Education and Clinical Center and an associate professor at Case Western Reserve's School of Medicine.
The circadian system regulates biological processes, such as production of the hormone melatonin, on a nearly 24-hour cycle in the absence of external cues. Melatonin levels, which normally rise in the evening (sleep time) and drop in the morning (wake time), are affected, in part, by light received through special receptors in the eye.
"Morning light, whether it is daylight or monochromatic blue light, helps synchronize the circadian system to a 24-hour solar day, which consolidates sleep during the nighttime," says Higgins. Based on these principles, researchers installed new blue-white lamp prototypes, created by GEengineers, in a daytime room at the Louis Stokes Cleveland VA Medical Center in Brecksville.
"Light levels typically are very low in assisted-living and nursing homes," says Mariana Figueiro, PhD, assistant professor at Rensselaer's Lighting Research Center in New York. "Such low light levels can keep patients in a biological darkness, so we implemented a 24-hour lighting scheme with more blue-white light during the day and yellow-white light at night." Preliminary results were encouraging.
Patients' sleep at night improved and most experienced increased wakefulness during the day. In addition to changing environmental lighting, the team, along with researchers from Rensselaer and a small business manufacturer, TopBulb.com LLC, are working on another option: goggles that emit blue light directly into the retina.
"With goggles, people can wear them for two hours each day while still doing their chores and continuing their daily lives," says Figueiro. Next, researchers plan to implement similiar lighting techniques in the homes of people with Alzheimer's to measure the circadian light exposure for both caregivers and their patients.
Says Higgins: If we could all get an hour of really good daylight each day, we would have a much better chance of getting what we all hope for-a good night's sleep."