The Study
The glymphatic system clears amyloid beta and tau from brain to plasma in humans
This study showed that when people sleep, their brains flush out certain brain goo (called amyloid and tau) into their blood better than when they stay awake. It doesn’t prove that sleeping stops Alzheimer’s, just that this flushing happens more during sleep.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
While you sleep, your brain flushes out harmful proteins linked to Alzheimer’s by pushing them into your blood — like a dishwasher for your brain.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 574 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This means sleep isn’t just rest — it’s your brain’s nightly detox.
- 2Skipping sleep may let toxic proteins build up over time, raising Alzheimer’s risk.
- 3After a good night’s sleep, plasma levels of Alzheimer’s proteins (Aβ42, p-tau181) rose by up to 98% more than after staying awake, especially in people without brain plaques.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nature Communications
Year
2024
Authors
P. Dagum, Donald L. Elbert, L. Giovangrandi, T. Singh, Venky Venkatesh, Alejandro Corbellini, R. M. Kaplan, S. Levendovszky, Elizabeth Ludington, K. Yarasheski, Jeffrey Lowenkron, C. Vandeweerd, M. M. Lim, Jeffrey J. Iliff
Related Content
Claims (6)
Chronic lack of sleep leads to higher levels of amyloid-beta and tau proteins in the brain due to reduced clearance by the glymphatic system during deep sleep.
In healthy older adults, lower resistance in brain tissue during sleep is directly linked to higher levels of amyloid-beta and tau proteins clearing into the bloodstream overnight, and this factor explains more than half the variation in these proteins among people with amyloid pathology and over 90% among those without.
In healthy older adults, one night of normal sleep raises levels of amyloid-beta and tau proteins in the blood the next morning compared to a night without sleep, and this increase is largest in people who do not have amyloid buildup in their brains.
During sleep, the ratio of certain abnormal tau and amyloid-beta proteins in the blood increases because the glymphatic system removes more of the forms that tend to clump together, creating a measurable pattern that reflects protein clearance rather than protein production.
In healthy older adults, longer periods of deep sleep stages N2 and N3 are linked to greater amounts of amyloid-beta and tau proteins appearing in the blood after sleep, and this link is stronger in those who do not have amyloid buildup in the brain.
When a person is deprived of sleep, metabolic activity in brain synapses increases plasma levels of amyloid-beta and tau proteins in the morning more than the brain's clearance system can remove them, resulting in higher protein concentrations than during normal wakefulness.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.