Installing a particular kind of light in nursing homes could soothe residents with dementia and improve their sleep and eating patterns, according to recently published research findings.

The lights were put in the rooms of 14 residents with dementia for a period of four weeks, during which researchers used standardized tools to track sleep quality and duration, depression and agitation. All improved significantly, the investigators found.

“It is a simple, inexpensive, non-pharmacological treatment,” said principal author Mariana Figueiro, Ph.D., associate professor and Light and Health program director of the Lighting Research Center at Rensselaer Polytechnic Institute in Troy, NY. “The improvements we saw in agitation and depression were very impressive.”

Nursing staff also reported that the patients were eating better, although this was a subjective impression, the investigators noted.

The blue-white lights used in the study were about 300 to 400 lux. This would be an appropriate light level for an office conference room, according to government guidelines. The lights had a “color temperature” of more than 9000 K. This is in the range of a white LED bulb, according to information from Florida State University.

The light therapy works by acting on the body’s circadian responses, the researchers stated.

The findings appear in the journal Sleep and were presented Monday at the American Academy of Sleep Medicine’s SLEEP 2014 conference in Minneapolis.