A recent study conducted by George Washington University (GW) has uncovered that a significant number of cocoa products in the U.S. contain heavy metals at levels exceeding safety guidelines. The study, titled “A Multi-Year Heavy Metal Analysis of 72 Dark Chocolate and Cocoa Products in the U.S.,” was published on July 31, 2024, in Frontiers in Nutrition.
The research analyzed 72 cocoa products over an eight-year period, focusing on the presence of lead, cadmium, and arsenic—metals known to pose health risks if consumed in large quantities.
Led by Leigh Frame, director of integrative medicine at the GW School of Medicine and Health Sciences, and medical student researcher Jacob Hands, the study found alarming levels of contamination in many popular cocoa products.
Frame emphasized the need for moderation in consuming foods known to contain heavy metals, such as chocolate, large fish like tuna, and unwashed brown rice. She highlighted the impracticality of completely avoiding heavy metals in food but stressed the importance of being mindful of both the type and quantity of food consumed.
The research revealed that 43% of the tested products surpassed the maximum allowable dose levels for lead, and 35% exceeded the safe limits for cadmium. None of the products tested surpassed the threshold for arsenic.
Interestingly, products labeled as organic were found to have higher levels of both lead and cadmium compared to non-organic items, raising concerns about the safety of organic cocoa products.
While consuming a single serving of these cocoa products may not pose immediate health risks based on median concentration levels, the study warns that frequent consumption or combining these products with other sources of heavy metals could lead to dangerous exposure levels.
Foods high in lead, such as shellfish, organ meats, and items grown in contaminated soil, and cadmium-rich foods, including certain seaweeds, should be consumed with caution to avoid cumulative exposure.
The findings urge consumers to be aware of potential cumulative risks, particularly from organic cocoa products, which may have higher heavy metal concentrations.
Despite the known health benefits of dark chocolate, such as improved cardiovascular health and cognitive performance, the presence of heavy metals poses a new concern that consumers and researchers need to consider. The study underscores the need for more comprehensive research into the health impacts of heavy metal contamination in food.