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Dynamic light study shows positive impact on Alzheimer’s sufferers

The results of a recent study into the effects of circadian lighting on Alzheimer’s patients are now available. The study was conducted by the ORPEA Group in cooperation with Nice University Hospital, Le Centre d’Innovation et d’Usages en Santé (CIU-Santé) and TRILUX lighting. Findings confirm that dynamic circadian lighting has significant, positive effects on the wellbeing of Alzheimer's sufferers. During the study residents benefited from longer sleep cycles and improved sleep quality, resulting in a distinct reduction in night time behavioural disturbances and anxiety symptoms. In a second step, they will investigate the possibility of reducing sedative medication, which would mean further benefits for mental and physical health. Simultaneously, ORPEA is planning to implement dynamic light at more of its facilities.

The ORPEA Group, which has over 730 facilities across Europe, is one of the largest European providers of care services, including residential facilities for older people, rehabilitation centres and psychiatric clinics. It is well known for promoting drug-free treatment of neurodegenerative diseases. The study analysed the influence of dynamic light on various Alzheimer's disease symptoms at the ORPEA Group Valenton care home near Paris. TRILUX lighting solutions, which replicate the natural rhythm of daylight, were installed in corridors, common rooms and relaxation rooms. Over a period of 42 days the effects of the dynamic light on the length of sleep phases, night time behavioural disturbances and anxiety symptoms was analysed.


Sleep is a major influencing factor

In up to 44%[1] of cases, neurodegenerative diseases like Alzheimer's are connected to abnormal sleep patterns. The disturbed sleep pattern results in a reduction in cerebral function regeneration. The consequences are disruption to concentration, sleepiness and the deterioration of existing symptoms. "The sleep-wake pattern can be stabilised by using a dynamic lighting solution. With light colour and light intensity oriented to the natural course of the sun during the day," explains Dr. Raphael Kirsch, Lighting Application Specialist at TRILUX. TRILUX is known for its research and development of lighting solutions that support and strengthen the biological rhythm and its systems have been successfully used in many hospitals, care centres and homes for the elderly.

As part of the study TRILUX installed its Liventy Flat and Plenar HD1-Q lighting solutions. The colour temperatures of the luminaires vary during the day moving from cool to warm light (3,000-  6,500 K). Controlled by a light management system, the luminaires simulate the 24-hour rhythm of daylight. During the analysis period, relatives granted permission for the activity, relaxation and sleep periods of residents to be actimetrically monitored. Staff recorded night time behavioural disturbances and anxiety symptoms with a neuropsychiatric inventory questionnaire (NPI-ES) and the COVI anxiety scale.

The study found significant improvements to the resident’s quality of life due to the installation of circadian lighting in common areas. The nominal sleeping period increased by 55 minutes over a 24-hour period and patients woke up less during the night. Similarly, it was witnessed that there was a significant reduction in night time behaviour disturbances (NPI score: -4.6 points from 12) and anxiety symptoms (COVI anxiety scale: -0.7 points from 4). Due to the impressive results, ORPEA decided to keep the TRILUX installation after the 42-day test period and has witnessed continued improvements of symptoms over the past nine months, which suggests that treatment with sedative medication can be reduced to promote concentration and performance. These findings are currently being validated in a further six-month study by Nice University Hospital.


[1] Treatment of sleep disturbances in Alzheimer’s disease. McCurry SM et al. Sleep Medicine Reviews 2000;4(6):603–28