Lighting-for-Seniors Study Hints that “Tunable” White LED Light Has Positive Effects

Unlike the Care Center’s incumbent fluorescent lighting, the new, replacement lighting provided “tunable white light”; i.e., white-light whose spectral components can be adjusted to create different effects, thanks to the versatility of the light-emitting diodes (LEDs) that serve as the lighting’s illumination source. In this case, the researchers were particularly interested in how the spectral adjustments – tuning – might affect residents’ melatonin levels. (Melatonin is a bodily produced hormone that regulates sleep and wakefulness. It’s also an antioxidant and so has a role in cell repair and as an anti-inflammatory. In humans, melatonin levels in the blood rise and fall during a person’s 24-hour sleep/wake cycle, or circadian rhythm, with high levels at night and low levels during the day.)

Applying guidelines developed by the Lighting Research Center of Rensselaer Polytechnic Institute, researchers used controls to create light whose lumen output and spectral composition were likely to suppress melatonin production from morning to midday, but less likely to suppress melatonin production in the evening and at night.

Results of the study, documented in a new research report, were startling:
• agitated behaviors such as yelling and crying decreased among three residents studied
• the need for psychotropic and sleep medications was significantly reduced for one of the residents
• the number of recorded patient falls decreased in the corridor studied
• according to ACC staff, residents whose rooms were located elsewhere were now “hanging out” in the LED-illuminated corridor

According to National Lighting Bureau Chair David R. Errigo (LumenOptix, Inc.), “The study is too small to generate unquestionable conclusions. However, the study’s results seem to validate many emerging hypotheses about both natural and electric lighting’s ability to have vital impacts in health-care facilities, especially those facilities that serve the needs of the elderly. To some extent, the more we learn about lighting, the more we realize what we don’t yet know, with the key word being ‘yet.’ The pace of research is accelerating at a rapid rate; new findings seem to be reported weekly. This is an extremely exciting and extraordinarily optimistic time for those of us involved in lighting, as we seek to understand what lighting can do beyond its traditional role as an aid to human vision.”

The U.S. Department of Energy (DOE) report about this project – Tuning the Light in Senior Care: Evaluating a Trial LED Lighting System at the ACC Care Center in Sacramento, CA – is available free of charge from the National Lighting Bureau.