Alzheimer's Disease Linked to Lack of Sleep: Study

Alzheimer's disease is the sixth leading cause of death in the United States and affects about 5.3 Americans, according to the Alzheimer's Association. One in three seniors die with Alzheimer's or other types of dementia and about $226 billion was spent on the disease in 2015.

Researchers from Oregon Health & Science University in Portland have recently found how lack of sleep may increase the risk for developing dementia, NPR reports. According to brain scientist Jeffrey Iliff, the brain clears out toxins linked to Alzheimer's as people sleep, and those who don't get enough quality sleep will have those toxins accumulate and bring damage to the brain.

For years, scientists have studied the relationship of sleep to the development of Alzheimer's disease and have found that there is some kind of link between the two.

According to Popular Science, Iliff and his team of researchers are set to conduct a one of a kind research to take a closer look at the key process in the brains of sleeping humans.

"It's very clear that sleep disruption is an underappreciated factor," Dr. Matthew Walker of the University of California, Berkeley told AP in July. "It's a new player on the scene that increases risk of Alzheimer's disease."

Disrupted sleep patterns are common among patients in the early stages of Alzheimer's, and scientists attribute this to the buildup of beta amyloid plaque, a sticky amalgamation of proteins that collects in synapses and is a characteristic of Alzheimer's.

"Changes in sleep habits may actually be setting the stage [for dementia]," Iliff explained. Initially, researchers thought that sleep disruption was simply because Alzheimer's disease was "taking out the centers of the brain that are responsible for regulating sleep."

However, researchers at Washington University in St. Louis found in 2009 that the sticky amyloid plaques linked to Alzheimer's disease develop faster in brains of sleep-deprived mice. In 2013, Iliff and his team discovered that during sleep, a cleansing process takes place in the brains of animals.

Iliff explained the process saying, "the fluid that's normally on the outside of the brain, cerebrospinal fluid—it's a clean, clear fluid —it actually begins to recirculate back into and through the brain along the outsides of blood vessels."

The cleansing is galled glymphatic system, a waste-disposal process in which the toxins that form Alzheimer's plaques are removed. Researchers have studied this in mice, and the next step would be to study it in humans.

"We have to find a way to see the same sort of function, but in a way that is going to be reasonably noninvasive and safe," Iliff said. The researchers plan to use the world's most powerful magnetic resonance imaging machines found in the OHSU, which is able to detect changes to indicate when the glymphatic system takes place in the brain. If the research is a success, scientists can move on to study more treatments for Alzheimer's.