In theory, nutritional supplements are an ingenious bit of food science — products formulated to shore up the gaps in your meal plan and ensure you’re getting enough of what you need to perform well both in and out of the gym. In practice, supplements aren’t always that straightforward and, in fact, may be doing a whole lot more than supplementing your nutrition.
A new study published in JAMA Network, (1) an open-access medical journal published by the American Medical Association, revealed some startling findings about the quality and composition of a large number of sport supplements.
Namely, that as much as over 10 percent of nutritional supplements may contain one or more ingredients that have been previously banned by the Food and Drug Administration (FDA).
First things first, the results. The paper, authored by Cohen et al., attempted to cross-reference the information on the nutrition labels of dozens of individual nutritional supplements with what was actually in the powder.
According to the paper, “Dietary supplement products were included … if they were labeled as containing at least one of the following ingredients:”
- R vomitoria, a plant extract containing alpha-yohimbine
- methylliberine, a “caffeine-like compound”
- halostichine, a partial Beta2-adrenergic agonist
- turkesterone, a plant steroid
- octopamine, described as “norepinephrine-like”
In total, the study analyzed 57 individual products that met the above criteria. Some of their findings include:
- 40 percent of products “did not contain a detectable amount of [a] labeled ingredient.”
- 11 percent of products contained ingredient quantities within 10 percent of what was listed on the label.
- 12 percent of products contained traces of at least one FDA-prohibited ingredient.
- 89 percent of product labels did not accurately disclose the ingredients found within.
Among those 12 percent of products containing banned substances, the authors found traces of five different FDA-prohibited ingredients, including 1,4-dimethylamylamine, deterenol, octodrine, oxilofrine, and omberacetam.
They highlighted that one individual product contained as many as four different banned substances, though the brand wasn’t mentioned by name.
What’s more, Cohen et al. also expanded their discussion of inaccurate supplement labels by citing some of their other work from 2013, (2) which purported that nearly half of dietary supplements contained inaccurate amounts of caffeine as displayed on their labels.
Methods & Limitations
To construct this study, the authors purchased 57 different botanical sports supplements online, based on whether they were labeled as containing R vomitoria, methylliberine, turkesterone, halostachine, or octopamine.
The supplement powders were reconstituted in methanol and analyzed for both the presence and quality of listed ingredients via liquid chromatography. Regarding limitations, the authors assert that the following factors may have impacted the quality of their findings:
- The sample size of individual products purchased was small.
- Only one sample from each brand was analyzed.
- Products were only analyzed if they were listed as containing at least one of the five “targeted ingredients.”
Cohen et al. conclude their report by noting that, “It is not known whether the results are generalizable to other botanical ingredients in sports supplements, or whether quantities might vary among batches within a given brand.”
They suggest that clinicians and consumers should exercise caution about supplements “with purported stimulant or anabolic effects.”
[Related: Does Caffeine Really Cancel Out Creatine?]
What It Means for You
In plain language, the researchers collected dozens of different supplements that were marketed as containing a series of performance-enhancing ingredients. Not only were the nutrition labels for these products partially inaccurate, but some even contained notable traces of substances banned by the FDA.
Do these findings extend to all nutritional supplements on the market? Not necessarily. The authors only analyzed products based on five performance-enhancing ingredients, some of which are quite niche and not particularly common in market-leading products.
One of the study’s most compelling findings was that among the products that contained detectable amounts of listed ingredients, actual quantity ranged from 0.02 to 334 percent of what was listed.
Broadly speaking, this study shines a light on something that industry insiders and supplement fanatics alike have long known: Nutritional supplements hardly contain exactly what they say they do in the exact quantities listed, and many ergogenic supplements designed to boost performance in the gym haven’t been extensively tested by the FDA.
Should you toss out all the tubs in your supplement cabinet, skip the whey protein, or ditch pre-workout? Probably not. But do understand that, at least according to this data, you may be unknowingly ingesting some ingredients not found on the nutrition labels of those products.
More Nutrition Content
- Your Ultimate Guide to Pre- and Post-Workout Nutrition
- Inside the Creatine Shortage Affecting Customers and Brands
- Pre-Workout & Alcohol: The Risks You Need To Know
- Cohen, P. A., Avula, B., Katragunta, K., Travis, J. C., & Khan, I. (2023). Presence and Quantity of Botanical Ingredients With Purported Performance-Enhancing Properties in Sports Supplements. JAMA network open, 6(7), e2323879.
- Cohen, P. A., Attipoe, S., Travis, J., Stevens, M., & Deuster, P. (2013). Caffeine content of dietary supplements consumed on military bases. JAMA internal medicine, 173(7), 592–594.
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