An MRI showing Alzheimer's Disease. Photograph: BSIP/UIG/Getty Images
Sleeping poorly or not getting enough rest may result in a type of brain abnormality associated with Alzheimer's disease, a study showed.
Brain images of adults with an average age of 76 found that those who said they slept less or poorly had increased build-up of beta-amyloid plaques, one of the hallmarks of Alzheimer's, according to research published today in JAMA Neurology. None of those in the study had been diagnosed with the disease.
Though more studies are needed to determine whether poor sleep increases plaque or the plaque causes sleep troubles, the findings suggest another way people might be able to identify early changes that foreshadow Alzheimer's. Research released at the Alzheimer's meeting in July suggested that memory lapses may be one of the earliest discernible signs of the disease.
"This is part of a larger message that healthy sleep is an important contributor to health in general and especially to successfully aging," said study author Adam Spira, an assistant professor in the Department of Mental Health at Johns Hopkins Bloomberg School of Public Health in Baltimore, in an Oct. 18 telephone interview. "It may be an important component in preventing Alzheimer's disease, but that remains to be seen."
More than 5 million Americans have Alzheimer's disease and the number is expected to triple by 2050, according to the Alzheimer's Association. Today's findings are the first to use brain images to identify the potential link.
The study included 70 older adults. They are part of the Baltimore Longitudinal Study of Aging, the U.S.'s longest running study on human aging. The participants reported they slept from no more than five hours a night to more than seven hours.
The scans showed that less sleep or more fragmented sleep resulted in greater plaque in the brain even after excluding the four participants with mild cognitive impairment or dementia.
People with Alzheimer's disease have fragmented sleep and rest for shorter periods than cognitively healthy adults. A study of mice last week in the journal Science suggested that during sleep more fluid can get into the brain, which in turns increases the removal of the plaque, Spira said.
"These findings are important, in part, because sleep disturbances can be treated in older people," he said in a statement. "To the degree that poor sleep promotes the development of Alzheimer's disease, treatments for poor sleep or efforts to maintain healthy sleep patterns may help prevent or slow the progression of Alzheimer's disease."