Poor Sleep Linked to Speedy Mental Decline in Older Adults

Sharon Moore July 03, 2014

Sleeping problems are common among older adults, with many of them getting just about 6 or 7 hours of slumber. Now, new research from the Duke-NUS Graduate Medical School Singapore found evidence that lack of sleep triggers mental decline at a faster rate.

For the study, researchers examined the data of 66 older Chinese adults, from the Singapore-Longitudinal Aging Brain Study. Participants underwent structural MRI brain scans measuring brain volume and neuropsychological assessments testing cognitive function every two years. Additionally, their sleep duration was recorded through a questionnaire. Those who slept fewer hours showed evidence of faster ventricle enlargement and decline in cognitive performance.

"Our findings relate short sleep to a marker of brain aging," said Dr June Lo, the lead author and a Duke-NUS Research Fellow. "Work done elsewhere suggests that seven hours a day for adults seems to be the sweet spot for optimal performance on computer based cognitive tests. In coming years we hope to determine what’s good for cardio-metabolic and long term brain health too," added Professor Michael Chee, senior author and Director of the Centre for Cognitive Neuroscience at Duke-NUS.

Past research has examined the impact of sleep duration on cognitive functions in older adults. Though faster brain ventricle enlargement is a marker for cognitive decline and the development of neurodegenerative diseases such as Alzheimer’s, the effects of sleep on this marker have never been measured.

The findings were published in the journal Sleep.

Changes in Sleep as We Age

Over a typical lifespan, the amount of time we spend each day sleeping declines. Adults through middle age need at least eight hours, and although the elderly may still require up to eight hours, they may struggle to obtain those hours in one block. In addition to sleep duration, sleep patterns also change with age. Most of the time, in older adults with sleeping problems, the REM sleep, which is often associated with dreaming, is not achieved. This stage, which is considered as the most important, is thought to assist in brain development, especially early in life.

If your sleep difficulties don’t improve through good sleep hygiene, you may want to consult your physician or a sleep specialist. Sleep is as important as proper diet and exercise. Without quality sleep, your health might be at risk.