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Bright Flashing Lights Will Not Prevent Alzheimer's Disease

A novel therapy is another gimmick that will waste your money

Key points

  • Brains use gamma waves (40 Hz) for specific functions that are not yet understood; patients with Alzheimer’s disease have diminished gamma
  • The ad claims that this device will restore cognitive function by flashing a light and noise at 40 Hz.
  • The device has been tested on a small group of AD patients but is not approved by the FDA.
  • The Proteus Phenomenon: Early studies are small and outcomes are positive, while later studies are big and negative.

It feels as though every week I find an ad on Facebook claiming that a miracle new treatment for Alzheimer’s disease has been discovered. As always, obtaining this miracle, that is not yet approved by the FDA or proven effective (you are encouraged to just ignore that little detail), will require providing your credit card number. The latest entry into this race: a light that flashes in your face, matched to a clicking noise, at a rate of 40 times per second. The ad claims that in only one hour each day this frequency can improve memory and attention and, this is the miraculous part, prevent the progression of Alzheimer’s disease by up to 60 percent. A truly astonishing claim such as this one is always the first clue of pseudoscience.

Is this flashing light bulb worth the high purchase cost? No one knows. Their preliminary results are unpublished and not yet reviewed by scientific peers. A senior director at the Alzheimer's Association stated that this novel therapy is not yet ready for prime time and suggested that much more research is required to prove that it is effective.

Let's look at their evidence that a flashing light and clicking noise can prevent or treat Alzheimer’s disease. The logic for their approach:

  1. our brains use gamma waves (40 Hz) for specific functions that are not yet fully understood
  2. patients with Alzheimer’s disease have diminished gamma waves
  3. let’s expose patients to a light flashing 40 times per second and see what happens

This miracle costs $275.

In one study performed by scientists with a strong financial interest in the product, a very small group of patients with mild Alzheimer's were studied for three months. Some of these patients were given equipment to take home and self-administer each day for one hour. The design is already worrisome: asking people with dementia to self-administer their own treatment without supervision is asking for problems. The rest of the patients experienced white noise. The authors claim that Alzheimer's-related brain degeneration slowed and that the treated subjects performed better on face and name recognition tests. Another study performed on a larger number of patients, by a different group of researchers with strong financial interests in this flashing light-sound product, reported improvements in sleep, memory, and cognition, as well as a reduction in brain atrophy. Once again, this long list of improvements should make one suspicious that the claims are too good to be true.

I have conducted basic pre-clinical research on Alzheimer’s disease since the 1970s and I’ve seen hundreds of similar fantastic claims that ultimately failed to provide any real benefits to patients. This scenario is so common that it has a name: The Proteus Phenomenon: Early studies are small and outcomes are positive, while later studies are big and negative. It is far too soon to invest in such unproven therapy.

The fact that science has not yet discovered an effective treatment for dementia has not stopped people from selling elixirs or flashing lights with claims that they can reduce the effects of aging on the brain.

Why do so many people fall for this? Essentially, we want these drugs to do something, anything; so, we fool ourselves into thinking that they do. After all, you’ve just spent a lot of money on this thing. Fortunately, most of them are so utterly useless that they will not harm you. At this point in time in the 21st century, nothing—let me repeat that—nothing exists that can alter the course of Alzheimer’s disease.


Wenk, GL (2017) The Brain: What everyone needs to know. Oxford Univ Press