Study Reveals A New Sound Therapy Could Offer Hope In Alzheimer's Treatment

A new scientific study is giving fresh hope in the fight against Alzheimer's disease by using something very simple sound. Researchers say a special sound frequency may help the brain remove harmful substances linked to the disease, offering a possible new and noninvasive treatment path.

Although a definitive cure for Alzheimer's disease remains elusive, a new study on aging monkeys has piqued the interest of scientists. Published in the "Proceedings of the National Academy of Sciences", the research explores the effects of 40 Hz sound waves on the brain.

The study revealed that this specific sound frequency helped clear beta-amyloid plaques from the brain, allowing them to reach the cerebrospinal fluid. This resulted in a reversal or improvement of Alzheimer's-related signs and symptoms. Beta-amyloid accumulation is considered a hallmark of Alzheimer's disease.

The research was conducted by scientists at the Kunming Institute of Zoology, Chinese Academy of Sciences. They found that 40 Hz auditory stimulation significantly increased the amount of beta-amyloid in the cerebrospinal fluid of aged rhesus monkeys. This effect persisted for approximately five weeks after the sound treatment ended.

The study, led by Hu Xintian, involved nine aged rhesus macaques, aged 26 to 31 years. These monkeys had naturally developed amyloid plaques in their brains, similar to the changes observed in humans with Alzheimer's disease.

The monkeys were exposed to 40 Hz sound for one hour daily for a week. The sound was delivered as a pure tone at 1 kHz. Following the treatment, levels of the beta-amyloid proteins Aβ42 and Aβ40 in the cerebrospinal fluid increased by approximately 206 percent and 201 percent, respectively. These elevated levels did not immediately decrease but remained high for the next five weeks.

The researchers suggest that these findings demonstrate the potential of novel, non-invasive physical therapies. This is particularly significant given that Alzheimer's and related diseases represent a major public health challenge today. According to estimates, approximately 139 million people worldwide could be affected by dementia by 2050.

This study builds upon previous research on 40 Hz frequencies, known as gamma waves. These waves have 40 oscillations per second and are associated with brain health and mood. Gamma waves typically range from 30 to 100 Hz.

A 2016 study at the Massachusetts Institute of Technology showed that exposing mice to 40 Hz light reduced amyloid levels in their brains. Later, the same research group combined light with sound. By adding 40 Hz auditory stimulation, they targeted brain regions associated with learning and memory, such as the temporal cortex and hippocampus.

These earlier studies showed a reduction in plaque buildup and improvements in cognitive function, further strengthening the results of the new monkey study and raising hopes for future Alzheimer's treatments.