Dark Chocolate Has an Even Darker Secret

Every so often, a study emerges touting the benefits of eating chocolate, with dark chocolate earning special praise. New research, however, has unearthed toxic heavy metals in dozens of dark-chocolate products sold by Amazon, Whole Foods, and GNC, among other retailers. For the peer-reviewed research published Tuesday in the journal Frontiers in Nutrition, scientists from the George Washington University picked up more than 70 products containing cocoa to test for toxicity over an eight-year period from 2014 to 2022, looking especially for lead, cadmium, and arsenic. The researchers found that 43% of the products they put through the paces had unacceptable levels of lead, using California's guidelines as a barometer, while excessive cadmium showed up in 35% of the products, which weren't called out in the study by name or manufacturer.

The Golden State allows 0.5 micrograms a day of lead before warranting a red flag; this research found some daily servings of dark chocolate contained up to 3.316 micrograms. Meanwhile, arsenic levels fell within acceptable limits for all the products. Interestingly, organic products studied by the researchers featured more contamination than nonorganic products. The Guardian notes that it's suspected lead is seeping into chocolate products during drying, processing, or packaging, while cadmium is thought to be a contaminant in soil. Still, although ingesting excess heavy metals can lead to health issues, some experts aren't pressing the panic button just yet.

"I don't think this is a massive cause for alarm," Brian Pavilonis of the CUNY Graduate School of Public Health and Health Policy, who wasn't involved with the study, tells ABC News, noting that lots of common foods contain low levels of heavy metals. Although young kids and pregnant women may be more at risk, some experts say that concern for most other people would typically arise only if someone was scarfing down "pounds and pounds" of dark chocolate a day, or eating dark chocolate alongside other foods that also contain higher levels of heavy metals. The New York Times adds that most of the chocolates examined in this study were below the FDA's lead-level mandate. "I'm still eating chocolate, and I will be eating chocolate later today," study co-author Leigh Frame tells ABC. Still worried? The As You Sow nonprofit keeps a running list of toxins in chocolate products. (More discoveries stories.)