Brain Supplements: Do They Really Work?

Like most adults over the age of 65, my wife and I have noticed some difficulty recalling names as we get older. We all worry that our minds will fail us and wonder if there is any validity to those claims about dietary supplements to improve our brain function. Who hasn’t wondered if those ubiquitous ads about Prevagen, the jelly-fish supplement, have any truth to them? After all, they claim to be “clinically proven” to improve brain function.

To answer these questions, I decided to do some research. The first thing I learned is that there is big money to be made out there selling brain supplements. By some estimates, the dietary supplement market is expected to reach $350 Billion by 2026. With that amount of money up for grabs, you can be sure there is a lot of competition – and a lot of back-stabbing by competitors.

The first whole page of my Google search came up with competing claims for one brain supplement against another. One site listed their top five supplements while the next listed their top five – and all the reasons why the other site’s top five were bogus. There was an alarming lack of agreement – and a shocking lack of scientific credentials from those making their recommendations. It was obvious I would need to dig deeper to find the truth.

Deeper research was rewarding – at least to dispel the false claims of the brain supplement manufacturers and their fans. First of all, I learned that the makers of Prevagen, the most widely advertised brain supplement, has been warned by the Federal Trade Commission and the New York State’s attorney general about making deceptive claims in 2017. “The marketers of Prevagen preyed on the fears of older consumers experiencing age-related memory loss,” said Jessica Rich, director of the FTC’s Bureau of Consumer Protection. “But one critical thing these marketers forgot is that their claims need to be backed up by real scientific evidence.”

A 2019 article from the Journal of the American Medical Association (JAMA), written by neurologists and dementia researchers at The University of California San Francisco, says there is no known dietary supplement that prevents cognitive decline for dementia. I found support for this viewpoint in other scientific literature as well as the Harvard Medical School Health Blog. An excellent review of the literature can be found from the Department of Geriatrics and Palliative Medicine, Mt. Sinai School of Medicine in New York.

The key statement from this review can be found in the Abstract: “Currently, there are no effective preventive strategies for cognitive decline.”  However, there is reason for concern with the use of dietary supplements because of their potential interaction with other medications. The Abstract goes on to warn: “Considering the insufficient evidence for their efficacy, potential for interaction with other therapies and costs to patients, physicians should be aware of the use of dietary supplements among their patients so that they can advise their patients on the potential benefits and harms.”

The Most Commonly Used Supplements

The reviewers commented on the most commonly used supplements, their efficacy, and potential side effects:

  • Ginkgo biloba– Studies have found that there was no difference in dementia incidence in all participants or in the rate of progression to dementia in participants when compared to the placebo group. Ginkgo biloba may interact with antiplatelet or anticoagulation medications which may lead to bleeding. The incidence of hemorrhagic strokes in the ginkgo biloba group was twice as high as placebo.
  • Vitamins B6, B9, B12 – Supplementation with B vitamins did not demonstrate any improvement in cognitive performance compared with placebo. However, there was an increased incidence of depression in the high-dose supplement group.
  • Vitamin E– There was no difference in cognitive performance between the Vitamin E treated group and placebo. There was some evidence to suggest that higher intake diets of Vitamin E may provide some protection against development of dementia when compared to low dietary intake of Vitamin E but this was not found in the studies uses Vitamin E supplementsto diet. Further study of this is needed.
  • W-3 Fatty Acids – Studies of these unsaturated fatty acids (PUFA) have been inconsistent but to date there is no study that has found any association between fish or w-3 fatty acids demonstrating better cognitive function or less cognitive decline in over 6 years follow-up.
  • Vitamins A and C – Evidence for the protective effects of Vitamins A and C against cognitive decline, impairment, or dementia is inconsistent and insufficient to recommend Vitamin A or C supplementation for cognitive health.
  • Vitamin D –To our knowledge, there are no available randomized control trials of Vitamin D supplementation for the enhancement of cognition or prevention of cognitive decline and dementia.
  • Phospholipids:phosphatidylserine and phosphatidylcholine –
    These phospholipids are the second most frequently endorsed substance for older adults with memory complaints by proprietorsof dietary supplements. In a recent small study of 157 participants, there was some suggestion of better cognitive performance in 15 weeks’ follow-up when compared with placebo in a group using phosphatidylserine, a w-3 long-chain (PUFA) and longer-chain decosahexaenoic acid (DHA) plus eicosapentaenoic acid (PS-DHA). Larger trials are needed confirm these findings before recommending the use of phospholipid supplementation.
  • Ginseng –For adults with cognitive impairment or dementia, there were no randomized, placebo-controlled trials assessing the effect of ginseng. Further large randomized controlled trials are needed.



I conclude with this quote from the Mt. Sinai School of Medicine review: “There is little evidence today to suggest any benefit to the use of dietary supplements to improve cognitive function or delay the progression of dementia. The exception may be in Vitamin E supplementation among older adults with moderate dementia, but its harmful effects must be considered. Until further studies are available to better demonstrate the benefits of supplements on cognition, encouraging a balanced diet that contains essential vitamins and nutrients may reap more health benefits.”


  1. I’ve been taking Prevegen for the past 10 years and find that my memory has been sharper as a result. My father and two of his brothers and a sister all died from Alzheimer’s. I am therefore more concerned about my own probability of suffering the same fate.

    Comment by Carson Eddy on May 7, 2020 at 6:46 am

  2. Nice to hear it works for some people! What’s needed is good clinical double-blind studies but those are lacking now.

    Comment by Robert Roberts on May 7, 2020 at 9:22 am