Subdued lighting in care homes disrupts the natural body clock of Alzheimer’s patients, leaving them prone to insomnia and disrupted sleep, a study claims.
Patients battling the most common form of dementia often spend most of their day indoors, particularly if they are stuck in a care home.
Researchers fear this may make them suffer sleep disturbances, and leave them more agitated and depressed.
In a breakthrough, scientists at the Rensselaer Polytechnic Institute in New York found a lighting intervention eased the physical changes in patients.
After six months, the participants in the trial showed significant decreases in sleep disturbance, depression and agitation.
The findings, led by Dr Mariana Figueiro, were today unveiled at a major Alzheimer’s conference in Chicago.
Patients battling the most common form of dementia often spend most of their day indoors, particularly if they stuck in a care home
She said: ‘The constant dim light typically experienced by people living in residential care facilities may be an underlying cause of the sleep pattern disturbances so commonly found in this population.’
The researchers found that increasing light during the day and making sure lights go off at night resets the body’s ‘circadian rhythm’ -the biological clock that regulates sleeping cycles.
Forty-three care home residents with dementia took part in the four week-long trial of lighting interventions.
They were exposed to alternating periods of lighting, which either stimulated their circadian rhythm, or didn’t.
This was measured by testing how much their body suppressed the production of the sleep-inducing hormone melatonin – a marker of the circadian system.
Personal light meters measured exposure given to each participant from natural light or custom-designed LED light tables.
Each volunteer was also quizzed on their sleep disturbances, mood and agitation for the study.
Participants reported less sleep disturbances, signs of depression and agitation when there were exposed to the LED light tables.
Dr Figueiro and colleagues found the positive effects remained, when the study was repeated over a period of six months on 37 residents.
Dr Carol Routledge, director of research at Alzheimer’s Research, welcomed the findings of the ‘positive’ study.
She said: ‘Getting a good night’s sleep is important for our brain and has many wider health impacts.
‘Many people with dementia experience sleep problems and understanding how we could minimise these symptoms could lead to important benefits.’
Dr Routledge called for further trials to see if lighting interventions really can help thousands of patients with dementia.
The results of the study were presented at the Alzheimer’s Association International Conference in Chicago.