Less Sleep Older Adults Get Faster Their Brains Age

A new study finds strong evidence that the less sleep older adults get, the faster their brains age.

Several studies in the past have linked sleep problems with memory impairment in older people. Adding evidence to this is the new study led by researchers at Duke-NUS Graduate Medical School, Singapore, that links less sleep in older adults to premature aging of the brain. 

The impact of duration of sleep on cognitive function among the aging population has already been evaluated. One of the markers of cognitive decline and development of neurodegenerative diseases like Alzheimer's is the faster brain ventricle enlargement. But not much is known about the effect of sleep on this marker.

In this study, the researchers evaluated data of 66 Chinese adults of ages 55 and above who were a part of the Singapore Longitudinal Aging Brain Study. The participants underwent structural MRI brain scans to measure the brain volume and every two years neuropsychological assessments were done to test cognitive function. The researchers also recorded the participants' sleep duration.

The researchers noticed that those who had less sleep had 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(2) 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.

This latest study relevant to Singapore's rapidly ageing society, paves way for future work on loss of sleep and its contribution to cognitive decline including dementia.

The finding was documented in the journal SLEEP.