Test of benefit of blue-white light on dementia patients
28 May 2009
A team of lighting and nursing researchers in the US are testing the
effects of blue-white light on dementia patients in a long-term care
facility to see if simulating daylight can have health benefits for the
patients who spend long periods indoors.
The researchers from Case Western Reserve University’s Frances Payne
Bolton School of Nursing and the School of Medicine, the Geriatric
Research Education and Clinical Center at the Louis Stokes Cleveland
Veterans Affairs Medical Center (GRECC), Rensselaer Polytechnic
Institute’s Lighting Research Center and GE Consumer & Industrial have
begun to test in a long-term care facility where daylight, which has
proven health benefits, is not readily available.
The researchers removed some standard fluorescent lighting and
installed new blue-white lamp prototypes developed by GE scientists at
the company’s Nela Park campus.
Research team members hypothesize that periods of blue light, like
daylight, can help regulate the sleep-wake rhythm, which is a
behavioural pattern linked to the 24-hour biochemical circadian cycle of
the hormone melatonin. Depending on the level of the hormone, people are
awake or sleepy.
The researchers want to regulate the sleep-wake cycle by regulating
the amount of exposure to blue-white (wakefulness) and yellow-white
(sleepiness) light. By increasing exposure to blue-white light during
the day and yellow-white light in the evening, researchers hope to help
patients regulate their sleep-wake cycles so that they are more awake
during the day and more asleep at night.
Patricia Higgins, associate professor at the Bolton School of Nursing
and one of the lead investigators, says the project may prove to be
especially beneficial for people suffering from dementia.
In a recently conducted pilot study with five male patients, each
suffering from dementia and living in a long-term care facility,
researchers installed the blue-white lights in an activities room where
most residents gathered for meals and daytime activities.
“We wanted to see whether lighting could affect the participants’
sleep-wake rhythms,” says Higgins. “While the group was small, the
results show promise in raising activity levels during daytime hours and
increasing sleep at nighttime.”
The researchers plan a larger study with residents with dementia at
two Northeast Ohio long-term care facilities. The study will include men
and women to see if light impacts the genders differently.
An unexpected side effect of the lighting is that once adjusted to
the blue-white light, most employees reported that they liked the new
For a number of decades it has been known that light affects how
people feel. Those particularly sensitive to changes in light have
benefited from a boost in the brightness of light sources. The new
lighting used in the test changes the colour without overpowering
individuals with brightness, according to the researchers.
“Why waste light if you can tune it to the right colour and maximize
the amount of useful light,” says Mariana Figueiro, assistant professor
at Rensselaer and program director at Rensselaer’s Lighting Research
Center. “Light is a good stimulus for the circadian system, which
regulates your sleep-wake cycles,” says Thomas Hornick, associate
director at the GRECC at the Veterans Administration Hospital and
associate professor at the Case Western Reserve University School of
Medicine. He says it is known that certain drugs do better when given at
the appropriate time in the circadian cycle.
As a safe, non-pharmacological intervention, researchers also hope to
apply information from the study to changing the lighting in hospitals
where patients may have a speedier recovery or improved quality of life
with a good night’s rest.
“We’re innovators at heart,” says Mark Duffy, engineering and
technology systems manager, GE Consumer & Industrial. “Our goal entering
this collaboration was to apply the passion and inventiveness, which we
bring to every customer need or application, to a project that has
implications for society at large. We’re proud to be part of this
If changing the lighting works to improve health, the researchers
plan to take what would be a natural next step: trying to influence
public policy to include new lighting standards for healthcare
Bookmark this page