Lead found in over-the-counter protein powder supplements

Protein Supplements

The protein supplement industry in the US had a total revenue of $2.069 billion in 2021, and it is expected to grow to over $10 billion by 2030. That represents a lot of people taking a lot of protein supplements!

In a recent report, over-the-counter protein supplements were found to contain potentially dangerous amounts of lead and cadmium. There is no safe blood level of lead in humans, and both lead and cadmium are toxic to the body’s heart, kidneys, gut, brain, respiratory and reproductive systems. Unexpectedly, the study found that “On average, organic protein powders had three times more lead and twice the amount of cadmium compared to non-organic products,” according to Jaclyn Bowen, executive director of the Clean Label Project, a nonprofit organization dedicated to transparent food labeling that performed the study and released the new report.

To perform the study, the Clean Label Project reports that they purchased 160 products from 70 of the best-selling brands of protein powders and then sent protein powder samples from each to an independent, certified laboratory for analysis. The lab ran nearly 36,000 individual tests on 258 different contaminants, including heavy metals like lead and cadmium, bisphenols, phthalates and perfluoroalkyl and polyfluoroalkyl substances, or PFAS, the so-called "forever chemicals."

Per the report, the lead levels in the protein supplement samples were measured and compared with California's strict Prop 65 regulatory guidelines for lead (oral ingestion: 0.5 micrograms per day). Overall, the report found that 47% of the 160 protein powder samples tested by the Clean Label Project in 2024 exceeded Prop 65 regulatory guidelines. About 21% of the powders contained lead levels twice as high as the Prop 65 limit. Nearly 80% of the plant-based and organic protein powders tested were over the Prop 65 limit for lead.

Previous research has shown that many foods, including root vegetables, baby food, imported candy, spices, and dark chocolate (cacao) often contains high levels of heavy metals, including lead. Bowen feels that heavy metal contamination is a global food safety problem. She stated, “These contaminants are basically everywhere, including in things that are being represented as health foods.”

Bowen recommended that consumers reach out to favorite brands to inquire about contaminant levels for help in decided which brands to purchase. The orginization did not report which brands or products had the highest lead levels, rather, only those that passed.

You can find a CNN news article here and the Clean Label Project blog post here. You can view and download the Clean Label Project report here.

Commentary: There are some important caveats to this report and associated news articles. This study was not published in a peer-reviewed journal (the gold standard for scientific research), the data are not publicly available, the sponsors of the study were not identified, nor were potential conflicts of interest by the author(s) stated. Hopefully, more rigorous studies will be forthcoming. Lead is known to adhere to the surface of roots of tubers (like carrots and potatoes) but it is not typically taken up by growing plants, therefore the findings are not completely unreasonable, but they should be independently verified. Lastly, this study used the stringent California Prop 65 lead "safe harbor level" of 0.5 micrograms ingested per day to determine toxicity. That's the law, as any ingestion above that level is considered unsafe. It is unclear what average blood level would result from ingestions of protein supplements above that daily dose.

A 2020 peer-reviewed study used different methodology and protein supplement lead concentrations obtained from other sources (including the Clean Label Project) to estimate the daily ingested amount of lead from supplements, then used modeling techniques to estimate blood levels of lead. Lead blood levels are highly correlated with clinical toxicity, and the CDC bases clinical toxicity on measured lead blood levels. This study found that the amount of lead in protein supplements was "not likely hazardous." Of course, the goal in children and pregnancy is a blood lead level of zero, and zero lead ingestion. Lastly, Harvard Health Publishing commented in 2022 on the first study by Clean Label Project of protein supplement contaminants, including lead, in The hidden dangers of protein powders.

Regardless, especially for pregnant women and children and those with underlying medical problems, eating anything with even trace amounts of lead should be avoided. There also may be numerous companies in violation of California's Prop 65 regulations, and they may need to provide clear and reasonable warnings about lead on their products or face penalties by the California Attorney General's office or public lawsuits. Consumer beware!