Bright light ‘improves dementia symptoms’

Using daytime bright light can improve symptoms of dementia, scientists claim.

Researchers at the Royal Netherlands Academy of Arts and Sciences, Amsterdam, found that giving older people daily supplements of bright light resulted in modest improvement in dementia symptoms.

And when they gave the participants melatonin, a hormone that helps regulate the daily body clock, the researchers saw an improvement to sleep.

The researchers found that bright light reduced deterioration of thinking, learning and memory skills by five per cent; reduced depressive symptoms by 19 per cent; and diminished the gradual increase in functional limitations by 53 per cent.

Melatonin reduced the time to fall asleep by 19 per cent and increased total sleep duration by six per cent.

However, caregivers reported increased withdrawn behaviour and differing moods.

In combination with bright light, melatonin reduced aggressive behaviour by nine per cent.

“The simple measure of increasing the illumination level in group care facilities [improved] symptoms of disturbed cognition, mood, behaviour, functional abilities, and sleep,” the researchers conclude.

“Melatonin improved sleep, but its long-term use by elderly individuals can only be recommended in combination with light to suppress adverse effects on mood.

“The long-term application of whole-day bright light did not have adverse effects, on the contrary, and could be considered for use in care facilities for elderly individuals with dementia.”

The research is published in the Journal of the American Medical Association (Jama).