Alzheimer’s Disease and Gamma Waves

Science is exciting, a never-ending maze of discoveries and slowly unraveling deep mysteries. Usually, science moves forward in tiny increments, iterative steps. Each small step builds on the next. But every once in a while, there comes about such a revolutionary idea; it sounds like science fiction. Those "out-of-the-box" ideas are what I love. They change my perspective and sometimes offer insight into scientific dogma. The novelty and wide-ranging potential is the reason I‘m intrigued with the microbiome. Although a relatively new body of work, it promises to turn most of what we know about health and disease on its head.

While walking a few days ago, I learned of one of these discoveries that sounds like science fiction. I was listening to a recent episode of Radiolab, called Bring Gamma Back, Again. The story was a continuation of a report on work at MIT where (in mice), 40Hz light or sound activates the immune system to stimulate the microglia to significantly increase their scavenging of beta-amyloid (the gunk that builds up in patients afflicted with Alzheimer's Disease). Synchronized light and sound decreased amyloid plaques not only in the visual and auditory cortices but throughout the cerebral cortex, including areas associated with memory and learning as well as higher-level executive function.

Furthering the work, scientists at Georgia Institute of Technology demonstrated that gamma stimulation with LED light-induced microglia produces a range of cytokines. Cytokines are proteins that regulate inflammation.

It is still unknown whether these results will translate into humans or if exposure is safe. Trying this at home is not recommended. If the findings do translate into humans, one could imagine unique frequencies of light and sound customized to specific disease. The scientists have set up a company, Cognito Therapeutics, to commercialize the technology.

If you'd like to hear what a 40Hz sound is like (do not use as a therapeutic device): Try this sound generator.

If you'd like to read more:

• Spreading the Word on a Possible Alzheimer's Treatment

• Brain Wave Stimulation May Improve Alzheimer's Symptoms

• Flickering Light Mobilizes Brain Chemistry That May Fight Alzheimer's

• An Hour of Light and Sound a Day Might Keep Alzheimer's at Bay

The scientific papers:

• Iaccarino HF, Singer AC, Martorell AJ et al. Gamma frequency entrainment attenuates amyloid load and modifies microglia. Nature. 2016;540:230-235.

• Garza KM, Zhang L, Borron B, Wood LB, Singer AC. Gamma Visual Stimulation Induces a Neuroimmune Signaling Profile Distinct from Acute Neuroinflammation. J Neurosci. 2020;40:1211-1225.