The testing group selected eight cocoa products promoted as sources of flavanols (polyphenols) and sold in the form of a capsule, powder, extract or dark chocolate bar. The health benefits associated with such products include improved blood flow, blood pressure and cholesterol levels.
More than triple the acceptable levels of cadmium were found in two products, each of which delivered a total amount of cadmium above the tolerable limit for certain people. Cadmium is a probable carcinogen, can cause kidney toxicity and softening of bones, and may affect fetal development, ConsumerLab.com said.
Although the U.S. FDA has not established limits on cadmium in supplements and foods, Canada limits daily cadmium exposure from natural health products to approximately 3 to 6 mcg, depending on body weight. The State of California requires a warning label on products with more than 4.1 mcg. The contaminated products contained 23.7 mcg and 13.3 mcg of cadmium per serving. These levels were confirmed in a second laboratory blinded to the identities of the products.
ConsumerLab.com found more than 100 mg of flavanols in a daily serving of some of the products, while others contained just 3 or 4 mg, and one had just 0.03 mg—despite claiming to be “a highly concentrated extract” which “should not be confused with less potent powdered herbs or extracts.” For potential therapeutic effect, a daily dose of 50-200 mg of flavanols is generally suggested.
Tests also revealed that the caffeine content in cocoas and chocolates varies widely, with a daily serving of some providing as much as in 1.5 cups of coffee while others provided almost none.