A new study from the Chinese Academy of Sciences suggests that a simple, low-cost sound therapy might offer a safe way to clear out the toxic brain proteins associated with Alzheimer’s disease.

Published in the Proceedings of the National Academy of Sciences on Thursday, the research demonstrates that listening to a specific low-frequency hum can significantly boost the brain’s natural ability to flush out beta-amyloid—the protein that clumps together to form damaging plaques in Alzheimer’s patients.

To see if sound could physically alter brain chemistry without the use of drugs, scientists worked with aged rhesus monkeys. Because these older monkeys naturally develop brain plaques very similar to those seen in human Alzheimer’s patients, they provide a much more accurate model for testing treatments than mice.
The experimental group listened to a 40-Hertz tone – a very low, rumbling frequency – for one hour a day over seven consecutive days.

The results were striking. The sound waves appeared to kickstart the brain’s waste disposal system. After the seven-day treatment, the levels of beta-amyloid proteins pushed out of the brain tissue and into the cerebrospinal fluid (the clear liquid surrounding the brain and spinal cord) jumped by more than 200%.

Essentially, the 40-Hz sound stimulated the brain to actively “wash” the harmful proteins away before they could do more damage.

While previous studies have shown that sound stimulation can clear amyloid proteins in mice, this primate study revealed two crucial advantages that bring the treatment closer to human reality:

– Long-Lasting Effects: In mice, the benefits of the sound therapy fade quickly. In these monkeys, however, the elevated protein clearance continued for more than five weeks after the sound sessions ended.
– A Safer Alternative: Current Alzheimer’s treatments often rely on expensive antibody drugs that carry severe risks, such as brain swelling and bleeding. Sound therapy is entirely non-invasive, low-cost, and sidesteps these dangerous side effects.