A recent article has highlighted a steep rise in "pseudomedicine" that markets many dietary supplements as benefiting brain health or preventing dementia [1]. Because there are currently no approved drugs to prevent or cure dementia, concerned individuals can fall prey to such advertisement that lack valid scientific evidence. In fact, this month alone, the FDA issued warning letters to over a dozen manufacturers of dietary supplements that have made claims of curing diseases including Alzheimer's [2][3].
The term pseudomedicine in the recent article refers to "interventions that are promoted as scientifically-supported treatments but lack credible efficacy data." When a product is advertised as benefiting cognitive health, it can be misleading as it implies the benefit applies to everyone equally. Many vitamins and minerals are necessary for optimal brain health, so if you are deficient in a specific vitamin, then supplementing with that vitamin may provide benefit. But if you get adequate levels of these vitamins or minerals from your diet, then supplementing with these products can potentially be harmful. For example, an analysis of numerous clinical trials reported that supplementation with vitamin E slightly increased mortality [4]. When something is necessary for optimal brain health, it doesn't mean that more is better.
Other types of pseudomedicine include invasive interventions that are not covered by insurance, including intravenous nutrition, detoxification, chelation therapy, and stem cell therapy [1]. These interventions may be performed by licensed medical professionals, but their efficacy and safety have not yet been thoroughly examined.
Examples of pseudomedicine refer to those with unproven claims to benefit cognitive health. Products promoted as having scientific evidence often lack strong unbiased efficacy and safety data. Individual testimonies that are subjective and not placebo-controlled are often advertised. It is important to remember that dietary supplements are not tested for safety or efficacy by the FDA like drugs are. And, just because a supplement is available over-the-counter does not guarantee it is safe.
In order to protect yourself from pseudomedicine, it is important to understand the multiple levels of evidence. A double-blind, placebo-controlled randomized trial is the gold standard of biomedical research, in which people are randomly assigned to receive either the intervention or a placebo (e.g., control), and both the participants and the researchers are "blind" to who received the intervention until the trial is completed. The strongest type of evidence is when a "meta-analysis" can be performed based on many double-blind, placebo-controlled randomized trials. This analysis combines data across those clinical trials to draw an overall conclusion.
Although observational studies are good for tracking large numbers of people for long periods and can identify interventions that correlate with health versus disease, they are not designed to prove that an intervention caused the benefit or harm. The weakest type of evidence includes preclinical studies in animal models or studies in test tubes. Given that 99.7% of drugs/compounds that cured Alzheimer's in mice have failed in human Alzheimer's, these types of evidence do not predict whether an intervention is effective or safe in humans.
Although there have been a few positive findings for cognitive health with regards to supplements, the benefits have generally been modest, mixed, or conditional. For example, B vitamins (B6, B12, and folate) are important for cell metabolism and reduce levels of the amino acid homocysteine that is associated with dementia, stroke, and coronary artery disease. Although B vitamin supplements did not improve cognitive functions in a clinical trial, there is some evidence that they may protect against cognitive decline in select people with high homocysteine levels or those who already have mild cognitive impairment [5-9]. Also, DHA is an omega-3 polyunsaturated fatty acid found in fatty fish. While DHA supplementation does not appear to improve cognitive function in most elderly people, it may provide some benefit in people with mild memory impairment [10][11].
There are currently no magic pills or supplements that you can take that will ensure lifelong brain health. But you can check our ratings of vitamins, supplements, food/drink, and drugs, where our team of neuroscientists evaluates the scientific evidence for and against their potential benefit and safety so you can make informed decisions based on the available evidence to date. Also, remember that lifestyle choices, such as eating healthy, sleeping well, exercising, reducing stress, being social, staying cognitively engaged, and managing illnesses have the greatest magnitudes of effects in protecting your brain and preventing dementia.
Yuko Hara, PhD, is Director of Aging and Alzheimer's Prevention at the Alzheimer's Drug Discovery Foundation. Dr. Hara was previously an Assistant Professor in Neuroscience at the Icahn School of Medicine at Mount Sinai, where she remains an adjunct faculty member. Her research focused on brain aging, specifically how estrogens and reproductive aging influence the aging brain's synapses and mitochondria. She earned a doctorate in neurology and neuroscience at Weill Graduate School of Medical Sciences of Cornell University and a bachelor's degree in biology from Cornell University, with additional study at Keio University in Japan. Dr. Hara has authored numerous peer-reviewed publications, including articles in PNAS and Journal of Neuroscience.
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