CO₂ pulses boost waste clearance in the ageing brain

The glymphatic system is a network of channels surrounding blood vessels in the brain. It clears waste products generated during the day, including proteins implicated in dementia. As we age, this system works progressively less well. Researchers are looking for ways to restore that clearance function.

Recent work, covered in the Fight Aging! newsletter, shows that intermittently elevated CO₂ concentrations promote glymphatic drainage of metabolic waste from the ageing brain. CO₂ is a powerful vasodilator: at higher concentrations it causes blood vessels in the brain to widen, increasing blood flow and, potentially, the fluid movement through the glymphatic channels. The researchers suggest that intermittent exposure to elevated CO₂ may offer a non-pharmacological way to support brain cleaning function.

How CO₂ acts on brain vasculature

Carbon dioxide (CO₂) is produced in the body as a metabolic by-product. Elevated CO₂ levels signal chemoreceptors to dilate blood vessels. In the brain, this leads to increased perfusion. That heightened blood flow creates a driving force for fluid circulation within the glymphatic system.

This is early-stage research conducted in mice. Whether the effect is reproducible in humans, and which CO₂ concentrations are safe and effective, remains to be established. Excessive CO₂ exposure can also be harmful, so this is not a recommendation to experiment at home.

Broader context: aquaporins and brain drainage

Parallel research focuses on aquaporins, proteins that facilitate water transport across cell membranes and play a key role in glymphatic drainage. Enhanced activity of aquaporin-4 was found to improve brain drainage in mice. Both lines of investigation point in the same direction: improving fluid clearance from the ageing brain is a promising but still early research area.

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