Whether it be a quick nap or a nighttime full of sleep, I love sleep. However, with a busy schedule and tons of commitments, I find myself prioritizing these events over my own rest. How much do these short-term habits affect your long-term health?
It has been noted that poor sleep is a telltale symptom of Alzheimer’s disease. As the disease progresses, people tend to wake up tired and their sleep becomes less refreshing. But, is unclear how and why restless nights are linked to Alzheimer’s disease. However, researchers at Washington University School of Medicine in St. Louis may have discovered part of the explanation.
Alzheimer’s disease affects approximately 5.7 million Americans, and the brain changes appear slowly and silently. Up to two decades before the characteristic signs of memory loss and confusion appear, amyloid beta protein begins to build up into plaques in the brain. The brain protein tau appear later, then atrophy of the key brain areas next. It is after all of these internal and unnoticeable changes that people start to show unmistakable symptoms of cognitive decline. But, what if there were a way to find the symptoms earlier?
The researchers at Washington University in St. Louis found that older people who have less slow-wave sleep, the deep sleep your body needs to consolidate memories and wake up feeling energized, have higher levels of the brain protein tau. Elevated levels of it has been linked to brain damage and cognitive decline, such as in Alzheimer’s. The relationship between sleep, the tau protein, and Alzheimer’s marks great strides in diagnosing and helping patients with the disease. Brendan Lucey, MD, an assistant professor of neurology and director of the Washington University Sleep Medicine Center believes that “measuring how people sleep may be a noninvasive way to screen for Alzheimer’s disease before or just as people begin to develop problems with memory and thinking.”
The study examined 119 people 60 years of age or older. Researchers monitored the participants’ sleep through a portable EEG monitor that strapped to their foreheads to measure brain waves, as well as a wristwatch-like sensor that tracked body movements. Participants also kept sleep logs, making note of both nighttime sleep and daytime naps. Additionally, researchers measured levels of amyloid beta and tau in the brain and spinal fluid. The results found that decreased slow-wave sleep coincided with higher levels of tau and amyloid. Lucey remarked that “the key is that it wasn’t the total amount of sleep that was linked to tau, it was the slow-wave sleep, which reflects quality of sleep. The people with increased tau pathology were actually sleeping more at night and napping more in the day, but they weren’t getting as good quality sleep.” In fact, daytime napping was significantly associated with high levels of tau.
This newfound information concludes that sleep monitoring may be an easy and affordable way to screen earlier for Alzheimer’s disease. Doctor’s may be able to ask a simple question: “How much do you nap during the day?” to identify people who could benefit from further testing. Overall, this study shows that regardless if you have Alzheimer’s or not, it is important to get enough slow-wave, deep sleep, or else you may reap the consequences later in life.