Experts all agree on one thing: lack of sleep is bad for your health. From short-term consequences like irritability, fatigue, and performance impairment, to serious health hazards if sleep deprivation becomes chronic.
However, a night or two of poor sleep shouldn’t have long term consequences. The following day may be harder to manage, but once the regular sleep schedule is back, everything turns normal. We’ve all been there, whether we had to pull an all-nighter, experienced jet lag, or were stressed or excited so much that we couldn’t sleep.
But, a new study from Uppsala University published in the medical journal Neurology hints that even a single night could have serious consequences, like an increase in a common biomarker of Alzheimer’s disease.
Participants were 15 healthy young male adults with an average age of 22 years and a healthy BMI index. They all stayed in a lab, had the same activity and meal patterns, and they also experienced two types of interventions at random. They either had a night of normal sleep, or they had to stay up and experience sleep deprivation. To stay awake, they were permitted to watch movies, play board games, and they were engaged in a conversation with experiment leaders to ensure wakefulness.
After each night, researchers took their blood samples and tasted it for several different markers of central nervous system health. Researchers looked at beta-amyloid, tau proteins, as well as levels of other factors that are commonly linked with neurological disorders.
This preliminary study found that acute sleep loss led to a 17.2% increase in tau protein blood levels. This molecule is located in the neurons of patients with Alzheimer’s disease, and it can start to accumulate decades before the symptoms appear. That is why finding the cause behind this increase in tau protein levels could help manage Alzheimer’s.
There were no changes in other biomarkers of cognitive health.
And while researchers state that the increase of tau blood level is not a good thing, it doesn’t have to be necessarily bad. Higher activity of neurons during wakefulness could lead to a higher synthesis of this protein, and it’s higher blood levels could simply reflect the overall increase. More tau in blood could be a direct consequence of the brain trying to clear itself.
A few limitations, like small sample size, were reported. Also, the subjects were all young, healthy males, and the results could be different in other groups. It is particularly interesting to see how things would play out in older individuals since they have an increased risk of dementia and different lifestyle habits.
However, the study could provide a valuable inside into an early onset of dementia and Alzheimer’s disease. It could help us understand how sleep impacts these conditions and possibly set new guidelines for lowering the risk of developing them.