CR tested a mix of brands, including smaller ones, such as Alter Eco and Mast, and more familiar ones, like Dove and Ghirardelli.
For 23 of the bars, eating just an ounce a day would put an adult over a level that public health authorities and CR’s experts say may be harmful for at least one of those heavy metals. Five of the bars were above those levels for both cadmium and lead.
The researchers found that cacao plants take up cadmium from the soil, with the metal accumulating in cacao beans as the tree grows. That’s similar to how heavy metals contaminate some other foods.
But lead seems to get into cacao after beans are harvested. The researchers found that the metal was typically on the outer shell of the cocoa bean, not in the bean itself. Moreover, lead levels were low soon after beans were picked and removed from pods but increased as beans dried in the sun for days. During that time, lead-filled dust and dirt accumulated on the beans. “We collected beans on the ground that were heavily loaded with lead on the outer shell,” DiBartolomeis says.
Some manufacturers with higher levels of metals in our tests said their products are below levels set by the settlement. Others said that the metals occur naturally in soil and that they take steps to try to reduce it. Alter Eco, Endangered Species, Theo, and Trader Joe’s did not respond.
Taking steps to reduce heavy metals in cacao can pay off: CR’s test results, after all, show that while contamination with heavy metals is common, it is not inevitable.
