Jens Asbjørn Bøgen
The brain has a nightly cleaning crew, and its stalling may be where Alzheimer’s begins.
For decades, the proteins that pile up in the brains of Alzheimer’s patients have been treated as the disease’s cause. A newer line of research turns that around and asks why the cleanup system, which flushes those proteins out while we sleep, slows down in the first place.
A team in Finland has now shown in healthy adults that the system can be switched on while people are wide awake. In a 29-person trial published in Nature Communications, researchers at the University of Oulu paired a nitric oxide-releasing blood pressure medication with roughly half an hour on a gently vibrating mattress and saw sharp jumps in two Alzheimer’s-linked proteins leaving the brain.
Blood levels of amyloid-beta 40, amyloid-beta 42 and the astrocyte protein GFAP rose significantly after the session, the University of Oulu said, while brain scans captured the proteins draining into the large veins at the back of the head. Tau, another protein tied to dementia, did not change significantly.
A sleep-like flush, without the sleep
The body’s lymphatic vessels carry waste out of most organs, but the brain relies on its own setup: cerebrospinal fluid that pulses through the tissue and washes debris into vessels around the brain’s membranes, mostly during deep sleep. When that system falters with age, amyloid-beta and other proteins accumulate.
The Finnish protocol tried to mimic the nighttime flush in the daytime. The medication produced a transient, nitric oxide-mediated widening of blood vessels that strengthened the slow vascular pulsations driving cerebrospinal fluid flow, while rhythmic whole-body vibration activated mechanosensitive Piezo1 channels in the vessel walls.
“The results suggest that harmful proteins were cleared from the brain more efficiently than usual,” doctoral researcher Johanna Tuunanen said in a statement from the university. The team reported that brain scans showed the clearance happening in the veins at the back of the head, consistent with the volunteers lying on their backs.
Promising, and very preliminary
The trial involved only 29 healthy volunteers aged 27 to 61, and it did not test memory or cognition. Rising blood amyloid is an indirect signal; it is consistent with clearance, but it is not proof the brain’s disease risk fell. The researchers also note the treatment may have temporarily loosened the blood-brain barrier, which could partly explain the protein spike.
An estimated 7.4 million Americans aged 65 and older are living with Alzheimer’s, according to the Alzheimer’s Association, a figure projected to climb to 13.8 million by 2060. Professor Vesa Kiviniemi, who leads the Oulu group, cautioned against trying to recreate the experiment at home: the nitric oxide pills can send blood pressure low enough to cause fainting.
The next trial, Kiviniemi said in the Oulu statement, will look at whether the technique helps patients with early memory impairment.
