Commercial samples of chocolate purchased in Brazil contained various levels of lead and cadmium.
These substances could have health implications for, especially for children, the American Chemical Society reported.
Chocolate has a number of health benefits thanks to its high levels of flavonoids and antioxidants in the cocoa. These two unwanted components are naturally occurring metals that can get into chocolate when crops suck it up out of the soil.
Lead and cadmium can cause "abdominal pain, headaches and anemia in adults." The effects can be even worse in children; it can cause behavioral changed, language delay and a number of other problems. Cadmium can be cause organ damage and has an estrogen-like effect that interferes with other hormones.
Solange Cadore and colleagues tested 30 milk, dark and white chocolate products bought in Brazil, some of which are shipped to the U.S. The team found dark chocolate had the highest levels of lead and cadmium, but all fell below the maximum consumption levels set in Brazil, the European Union (E.U.) and the World Health Organization.
The U.S. Food and Drug Administration recommended levels of lead in candy should not exceed 100 nanograms per gram of candy; two of the tested samples were found to contain 30 to 40 ng/g.
In terms of cadmium the researchers found that if a child who weighs 33 pounds eats a third of an ounce of chocolate a day they would consume a maximum of 20 percent of the E.U-suggested weekly intake of metal. The team noted only a fraction of led or cadmium absorbs into the bloodstream, but the high levels found in dark chocolate are still a cause for concern.
The findings were published in ACS' Journal of Agricultural and Food Chemistry. The authors acknowledge funding from the Conselho Nacional de Desenvolviemento Científico e Tecnológico, the Fundação de Amparo à Pesquisa do Estado de São Paulo and the Instituto Nacional de Ciências e Tecnologias Analíticas Avançadas.