Following up on its discovery in May of high levels of the toxic metal cadmium in several cocoa-based products, ConsumerLab.com recently tested additional, popular cocoa products sold in the U.S. to assess the extent of the problem. The independent testing company now reports the problem is widespread among cocoa powders, involving nearly every brand of cocoa powder tested.
Until now, the food most associated with cadmium contamination has been rice. Cadmium has caused Itai itai (or "Ouch ouch") disease in Japan and was reported this year at high levels (above 0.2 mcg per gram) in a large proportion of rice samples in the Guangzhou province of China. ConsumerLab.com found that nearly every popular cocoa powder it recently purchased and tested in the U.S. far exceeded this level, with concentrations in most products ranging from 0.9 to 1.5 mcg per gram. A daily serving of three products also contained more than 1 mcg of lead. Results were confirmed in a second independent laboratory.
"These high concentrations of cadmium are a disturbing surprise," said Tod Cooperman, M.D., president of ConsumerLab.com. The mission of ConsumerLab is to help consumers identify the best quality health and nutrition products through testing. For cocoa and chocolate products, this involves testing for flavanols which may help with blood flow, blood pressure, and cholesterol levels. However, ConsumerLab.com also tests all botanical products, including cocoa, for heavy metals.
"Although disease is very unlikely from the cadmium in just an occasional cup of cocoa, it seems wise to limit exposure to contaminated cocoa," Dr. Cooperman cautioned. He added, "If you are going to consume a contaminated product, be sure you are getting enough calcium, iron and zinc in your diet as these minerals may reduce the absorption of cadmium."
Although the U.S. Food and Drug Administration has not established limits on cadmium in supplements and foods, Canada limits daily cadmium exposure from natural health products to approximately 6 mcg for adults and 3 mcg for children. The State of California requires a warning label on products with more than 4.1 mcg. The contaminated products contained 2.8 mcg to 23.7 mcg of cadmium per suggested serving.
For its report, ConsumerLab selected and tested fourteen cocoa products sold in the form of a capsule, powder, liquid, chocolate bar, or nib, including products made from pure cocoa as well as extracts. It also reported on a product tested voluntarily through its Quality Certification Program. ConsumerLab.com found several hundred milligrams of flavanols in a daily serving of some of the products, while others contained just 3 or 4 milligrams, and one had just 0.03 milligrams - despite claiming to be "a highly concentrated extract." For potential therapeutic effect, a daily dose of 50 mg to 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 provide almost none.
Products which did not exceed contamination limits for cadmium and lead included a dark chocolate, a powder and a supplement each made from a cocoa extract, and three other cocoa supplements - although these contained very low levels of desirable flavanols. A cocoa (cacao) nibs product slightly exceeded the cadmium limit but was rich in flavanols.
Test results and comparisons for the products are found online in the report here. The report, which includes information about the uses, dosage, and potential side-effects of cocoa products, covers the following products:
Cacao by Advanced Physician Formulas
Ghirardelli 100% Unsweetened Cocoa
Hershey's Cocoa - Natural Unsweetened
Hershey's Special Dark Chocolate
Navitas Naturals Cacao Nibs
Navitas Naturals Cacao Powder
Nestle Toll House Cocoa
NOW Certified Organic Cocoa Powder
NuNaturals Pure Liquid Cocoa Bean Extract
Source Naturals ChocoLift
Sunfood Raw Cacao Powder
Swanson Full Spectrum Cacao
Trader Joe's Cocoa Powder Unsweetened