If you think that a bad night's sleep is harmless, think again. New research suggests that a single night of sleep deprivation can increase levels of a protein involved in Alzheimer's disease.
Scientists from the National Institute on Alcohol Abuse and Alcoholism (NIAAA) discovered that adults who experienced one single night of sleep deprivation showed an immediate increase in levels of beta-amyloid.
Beta-amyloid — also known as amyloid beta — is a sticky protein that can accumulate between brain cells and form "plaques." These plaques disrupt brain cell communication, and this is believed to play a key role in Alzheimer's disease.
Study co-author Nora D. Volkow, of the Laboratory of Neuroimaging at the NIAAA, and colleagues recently published their findings in the Proceedings of the National Academy of Sciences.
Alzheimer's disease is a progressive cognitive disorder characterized by memory loss and changes in behavior. It is the most common form of dementia, affecting around 5.7 million adults in the United States alone.
Past research has associated disrupted sleep with an increase in beta-amyloid levels, but Volkow and colleagues note that there have been some shortfalls in research.
"Despite the evidence," say the researchers, "that acute sleep deprivation elevates [beta]-amyloid levels in mouse interstitial fluid and in human cerebrospinal fluid, not much is known about the impact of sleep deprivation on [beta]-amyloid burden in the human brain."
A bad night's sleep increases beta-amyloid
To help shed light on how acute sleep deprivation influences brain levels of beta-amyloid, the team studied 20 healthy adults aged 22–72.
Using positron emission tomography imaging, the researchers measured beta-amyloid burden in the brain after one night of rested sleep and after one night of sleep deprivation.
After a single night of sleep deprivation, the researchers noticed an increase in beta-amyloid levels in the right hippocampus of the subjects' brains, as well as in the thalamus.
According to the authors, these findings provide "preliminary evidence for the role of SD [sleep deprivation] on [beta-amyloid] accumulation in the human brain."
Volkow and her colleagues note that they are unable to say whether a night of rested sleep could negate the accumulation of beta-amyloid caused by a bad night's sleep, but this is something that they plan to investigate in future research.
Still, they believe that their new study suggests that getting a good night's sleep may be crucial to our brain health. The authors conclude:
"Our results highlight the relevance of good sleep hygiene for proper brain function and as a potential target for prevention of AD [Alzheimer's disease]."