What to consider when evaluating nutritional supplements

It’s a seductive idea: find the right pill, and your memory will improve. Take a nutritional supplement, and existing problems with thinking skills will disappear. Simply put, is there scientific evidence to support such claims?

The public is inundated with advertising that promises better brain functioning with supplements, and as a result, consumers are literally buying into this promise in a big way. According to recent market data, consumers spend more than $90 million per month on products claiming to improve brain functioning.

But recent research has added to the debate over how impactful supplements can be.

On the one hand, in 2019, the AARP’s Global Council on Brain Health study found supplements to improve brain health have no effect. Most of the advertised “clinical studies” supporting a product’s ability to improve our brain health rely on unpublished data and testimonials, instead of well-conducted science.  There is also evidence that people may not be aware of the lack of scientific support available for brain health supplements, or the potential risks associated with taking them.

On the other hand, two recent studies published in high-profile journals (here and here) demonstrated cognitive benefits from multivitamin use. In these large-scale studies, the commonly used multivitamin Centrum, when taken daily over time, was associated with improved neuropsychological testing results, particularly if someone had a history of cardiovascular disease. The benefits found in people given a multivitamin were modest, but the findings offer some promise in a field otherwise fraught with false advertising.

(For a complete look at this research, visit the COSMOS trial website.)

It’s encouraging that scientifically rigorous research is being conducted to clarify potential effects of supplements on the brain. It does leave the lay person with a conundrum of how to evaluate whether to invest in supplements to improve their brain functioning.

A primer on supplements

No discussion of nutritional supplements can begin without some background on the difference between medications and supplements.

Prescription medications undergo rigorous evaluation of their safety and efficacy at multiple levels.  New compounds are initially tested in the laboratory and in animal models, then small scale studies determine whether the medications are safe for human consumption.  Later in the process, large randomized clinical trials are conducted to clarify if the medication actually does what it’s supposed to do.  These trials are double-blind, meaning that some people receive the new medication, others receive a placebo, and no one (including the scientists running the study) knows who gets what.  The U.S. Food and Drug Administration (FDA) then makes a final decision whether to release the drug in the general population.  While medications sometimes go to market and end up being problematic, the detailed and time-consuming process to get there increases the chances of them doing more good than harm.

The process with nutritional supplements is different.  Since the effectiveness and safety of supplements are not evaluated by the FDA, manufacturers can make claims about their products that may or may not be based in scientific research.  According to a 2020 study by the American Academy of Neurology, some brain health supplement companies may have lax manufacturing standards, such as including multiple unapproved drugs and using inconsistent doses of supplement ingredients, both of which could be harmful.  The bottom line: we should always investigate what manufacturers claim about the supplements they make.

Caveat emptor

While more rigorous monitoring of supplement manufacturing would be useful, the Federal Trade Commission (FTC) and other parties have intervened at times in the context of deceptive advertising.  For example, the company that manufactures one supplement, Prevagen, was sued by the FTC for misrepresenting purported brain health benefits of their product (the lawsuit ultimately resulted in a class action settlement for those who had purchased Prevagen). 

Another concern is that the effects of supplements on clinically prescribed medications are unclear.  As the Alzheimer’s Association has indicated, supplements have the potential to interact with or diminish the effects of medications prescribed to treat dementia.

Of course, checking with your physician is critical when considering a nutritional change, particularly if you have lower-than-normal nutritional levels.  For individuals with a balanced diet and no nutritional deficiencies, there currently does not appear to be compelling evidence to justify the use of over-the-counter supplements to promote or enhance brain wellness.  Simply put, there needs to be more well-conducted science that supports the decisions providers and consumers make about appropriate treatments.

Science-based lifestyle ‘treatments’

It is important to note that there already are some well-researched “treatments” associated with promoting brain and cognitive wellness.

Importantly, the best one appears to be exercise.  People who consistently engage in almost any form of cardiovascular exercise—walking, swimming, cycling, dancing, hiking, and so on—tend to have stronger cognitive abilities, experience growth in multiple brain regions, and have a significantly lower risk of developing Alzheimer’s disease.

There are similar benefits stemming from social activity, engagement in mentally stimulating hobbies, and eating a Mediterranean-style diet.  The science supporting the role of these lifestyle activities on brain health is extensive—dozens if not hundreds of studies have been conducted in these areas.  If you’re looking for something that’s good for your brain, body, and emotional health, these are all great options to consider, without equivocation.

Where to learn more

If you’d like to learn more about a specific nutritional supplement, one helpful resource is a website created by the National Institutes of Health: PubMed.  This is a large, well-regarded, and searchable online database where you can gather scientific information related to almost any field of study, including research on different supplements.  Being an informed consumer of any health-oriented product is essential, and the best decision to make about supplements is the one where science leads the way.