Protein supplements have become a daily habit for many Californians, who add them to smoothies, coffee and even oatmeal in hopes of boosting muscle recovery or managing weight.
But unlike baby food or prenatal vitamins, these products aren’t routinely tested for heavy metals.
A bill moving through the state Legislature would require manufacturers to test products for toxins like lead, cadmium, mercury and arsenic — and post the results.
“Even a small amount in a serving is a worrisome amount if you’re doing that every day,” said Susan Little, California legislative director of the Environmental Working Group, a sponsor of the bill.
This approach has worked before in California, she said. After the state required similar disclosures for baby food, contamination levels dropped.
Unlike prescription and over-the-counter drugs, the Food and Drug Administration does not review or approve supplements like protein powders before they’re sold. Instead, companies are largely responsible for making sure their products are safe.
“Our tests have found that toxic heavy metal contamination in protein powder is widespread and has gotten worse since we first analyzed these products 15 years ago,” said Brian Ronholm, director of food policy at Consumer Reports.
A recent report from the Clean Label Project tested 160 protein powder products and found that 47% exceeded California’s safety limits for toxic metals. Plant-based powders had about three times more lead than whey-based alternatives. Chocolate-flavored products contained four times more lead than vanilla. And organic products tended to have higher levels of lead and cadmium.
But that report has not been peer reviewed, and some scientists have noted that trace amounts of heavy metals can naturally occur in soil and food — meaning their presence doesn’t always signal a clear health risk.
Technically, there is no known safe level of exposure to lead. Medical experts say the biggest health risks tend to come from repeated exposure at higher levels — including reproductive problems, kidney damage and cognitive impairment.
Industry groups have pushed back. The Council for Responsible Nutrition, a trade association representing dietary supplement manufacturers, argues the bill would create unnecessary costs and confusion without improving safety.
If you’re worried about potential exposure, Stanford University nutrition scientist Christopher Gardner said it’s worth considering whether you need protein supplements in the first place.
He noted that while they may benefit elite bodybuilders, the vast majority of Americans — even those who regularly lift weights — can get enough protein from food. Most of the gains from strength training come from the exercise itself, not added protein.
“So, hedge your bets,” wrote Gardner in an email to KQED. “Eat foods, not protein supplements. What have you got to lose — and what do you have to gain?”
The bill has cleared its first committee on Wednesday and now heads to another vote.
If it becomes law, California would be the first state in the country to require this kind of testing and transparency.
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