Industry responds to report suggesting that protein powders contain unsafe levels of heavy metals

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A recent report released by the Clean Label Project (CLP) disclosed findings of high levels of lead and cadmium in over-the-counter protein powders^1,2. According to the report, 160 products from the top-selling brands, which represents 83% of the market were tested. Results showed that of these products, 47% exceeded the threshold for toxic metals set by California Proposition 65.

“Organic products, on average, showed higher levels of heavy metal contamination, with three times more lead and twice the amount of cadmium compared to non-organic products,” stated the report, with plant-based proteins showing three times more lead than whey-based ingredients, and chocolate flavored powders containing four times more lead than vanilla. CLP claims to have tested 258 chemicals and heavy metals, conducting 35,862 individual tests on contaminants. The story was picked up by CNN, highlighting CLP's results and quoting Jaclyn Bowen, its executive director. Andrea Wong, PhD, the Council for Responsible Nutrition's (CRN; Washington, D.C.) was also quoted in the article explaining that the report was not sufficiently transparent "about the criteria used for contamination thresholds and how products were selected."

“It is important to emphasize that the detection of contaminants, as highlighted in this report, does not inherently equate to a health risk," Wong explained in a statement. "Modern analytical techniques can detect even trace levels of naturally occurring elements, such as heavy metals, which are present in soil, air, and water. These trace levels are often well below established safety thresholds set by federal agencies like the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA)."

Wong says that the California Prop 65 limits are "uniquely stringent and not aligned with federal guidelines.” For example, Prop 65 limit for reproductive toxicity of lead is 0.5 mcg per day while FDA's interim reference level for the heavy metal in women of childbearing age has only recently been lowered to 8.8 mcg per day.

The Natural Products Association (NPA; Washington, D.C.) also took issue with the report and CNN's coverage of the report. “The Clean Label Project is full of it, and it’s a shame that no one at CNN did basic reporting by neither asking for the methodology for this sham of a study nor contacted the NPA for analysis and comment. Instead, CNN blindly reported what the Clean Label Project told them without verifying,” said Daniel Fabricant, PhD, president and CEO of the Natural Products Association, in a statement. “In 2020, they pulled the exact same stunt attacking collagen supplements, but this so-called study is nothing but hot air. When we asked them to disclose its funders and the full methodology of the collagen study, they did not respond and instead hid from the truth. Again, we are demanding that they disclose this so-called study’s methodology instead of peddling misinformation and profiting from referred products to online retailers listed on its website.”

A patchwork of regulations creates confusion for consumers and manufacturers, says Wong. “As we move toward ensuring safety and transparency, we must encourage a unified regulatory approach that upholds reasonable, evidence-based standards," suggests Wong. "Aligning state initiatives like Proposition 65 with federal guidelines would reduce confusion for consumers and manufacturers while maintaining public safety. CRN and its members remain committed to collaborating with stakeholders to promote rigorous, transparent, and uniform safety standards across the dietary supplement industry.”

CRN is encouraging CLP to “…publish its findings in peer-reviewed journals and provide recommendations grounded in scientific evidence.” This will provide consumers with transparency and further education materials.

References

1. Clean Label Project. 2024-25 protein powder category report https://cleanlabelproject.org/wp-content/uploads/CleanLabelProject_ProteinStudyWhitepaper_010625.pdf (accessed Jan 10, 2025).
2. LaMotte, S. Lead and cadmium found in muscle-building protein powders, report says https://www.cnn.com/2025/01/09/health/protein-powder-heavy-metals-wellness/index.html (accessed Jan 10, 2025).