Not getting enough sleep? A new study suggests poor sleep quality, daytime drowsiness, and other sleep problems may be linked to an increased risk of developing Alzheimer's disease.
In the United States, one in every three Americans admits they don't get enough sleep, while 45 percent of the world's population doesn't sleep well, too, according to the World Association of Sleep Medicine.
Sleep deprivation is considered a public health issue by the Centers for Disease Control and Prevention because disruption in sleep patterns has been tied to an increased risk of heart disease, stroke, and diabetes.
Soon, Alzheimer's and dementia may be added to this list, too.
Poor Sleep Quality Tied To Higher Alzheimer's Disease Risk
Researchers in Wisconsin have found that people with higher risks for Alzheimer's disease who had poor sleep quality, daytime drowsiness, and more sleep problems had more indicators for the disease in their spinal fluid than those who did not have any issues sleeping.
The indicators they detected were signs of brain cell inflammation and damage, as well as proteins amyloid and tau, all of which have been linked to Alzheimer's disease.
Tau is a protein that creates tangles in the brain, while amyloid folds and forms plaques. Such tangles and plaques — the hallmarks of Alzheimer's — are present in the brains of patients with the disease.
To determine the link between sleep quality and Alzheimer's, scientists examined 101 people whose average age was 63 years old.
At the time of the study, all participants had normal memory and thinking skills, but they were all considered at risk of developing Alzheimer's either because they carried a gene called apolipoprotein E (APOE) or because they had a parent with the disease.
All participants volunteered to give a sample of spinal fluid to be analyzed for markers of Alzheimer's.
Getting Enough Sleep
Barbara Bendlin, coauthor of the study and a researcher from Wisconsin Alzheimer's Disease Research Center, said their findings align with the theory that worse sleep quality may contribute to the buildup of Alzheimer's disease proteins in the brain.
Bendlin explained that detecting these effects in people who are close to middle age and are cognitively healthy suggest that the relationship between sleep and Alzheimer's proteins appear early. This provides a window of opportunity for intervention, she said.
However, Bendlin said the reason for the link is still unclear, and that not everyone with sleep problems is predestined to develop Alzheimer's disease in old age.
"We're looking at groups of people, and over the whole group we find the association of poor sleep with the markers of Alzheimer's," said Bendlin. "But when you look at individuals, not everyone shows that pattern."
In the meantime, Bendlin said further research is needed to solidify the risks of sleep deprivation in increasing the risks of Alzheimer's disease.
The findings of the study are published in the journal Neurology.