Study: Multiple dark chocolate products contain presence of lead and cadmium

A new study in Frontiers in Nutrition has found the presence of heavy metals in multiple dark chocolate products, specifically referencing lead and cadmium, echoing a separate report from last year.

The study was conducted by researchers at George Washington University School of Medicine and Health Sciences in Washington, D.C., who purchased and analyzed 72 "consumer cocoa-containing products" for "heavy metal contamination" with lead, cadmium and arsenic between 2017 and 2021. According to Michael Sainato with The Guardian, the names of the products or manufacturers were not disclosed in the study, which was conducted in line with California exposure and food safety guidelines.

The report shares that 43% of the products tested contained lead, 35% contained cadmium and 0% contained arsenic.

"This indicates that heavy metal contamination—in more than half of products tested—may not pose any appreciable risk for the average person when consumed as a single serving; however, consuming some of the products tested, or more than one serving per day in combination with non-cocoa derived sources heavy metals, may add up to exposure that would exceed the Prop 65 [maximum allowable dose level]," the study authors wrote, noting that "organic" products were significantly more likely to demonstrate higher levels of both cadmium and lead.