Inhaling high-dose CO2 cleared Alzheimer's tau protein in small study

A 12-person study found that intermittently inhaling high doses of carbon dioxide for 30 minutes lowered brain tau protein to normal levels and raised beta-amyloid in blood. The effect was temporary, with tau returning to baseline in under an hour. Results were presented at the Alzheimer's Association International Conference in July 2026.

• 12 participants wore masks switching to CO2 every 35 seconds
• Tau protein fell to normal levels but rebounded in under an hour
• Beta-amyloid in blood rose in all participants
• Effect is linked to the brain's glymphatic waste-clearing system