New research adds to the evidence that certain cocoa products contain lead and cadmium.
New research published Wednesday found heavy metals in dark chocolate, the latest in a string of studies to raise concerns about toxins in cocoa products.
The researchers tested 72 dark chocolate bars, cocoa powders and nibs to see if they were contaminated with heavy metals in concentrations higher than those deemed safe by California’s Proposition 65, one of the nation’s strictest chemical regulations.
Among the products tested, 43 percent contained higher levels of lead than the law considers safe, and 35 percent had higher concentrations of cadmium. Both metals are considered toxic and have been associated with a range of health issues. The study did not name specific brands, but found that organic products were more likely to have higher concentrations. Products certified as “fair trade” did not have lower levels of heavy metals.
But on the whole, the levels were not so high that the average consumer should be concerned about eating dark chocolate in moderation, said Jacob Hands, the lead author on the paper and a medical student at George Washington University School of Medicine and Health Sciences.
Nearly all of the chocolates contained less than the Food and Drug Administration’s reference limits for lead, which are less stringent than the California requirement. And while both cadmium and lead can carry significant health risks, it’s not clear at this point that eating a few squares of dark chocolate poses a risk to most healthy adults.
“Just the fact that it exists doesn’t necessarily mean immediately there’s going to be some terrible health consequence,” said Laura Corlin, an associate professor of public health and community medicine at Tufts University School of Medicine who was not involved in the study.