Long viewed as healthier than other sweet treats, some kinds of dark chocolate contain potentially dangerous amounts of heavy metals, according to research released Thursday by Consumer Reports.
Dark chocolate, loaded with antioxidants, is often called a healthier chocolate.
But a new study from Consumer Reports said some kinds of dark chocolate contain potentially dangerous amounts of heavy metals.
James Rogers with Consumer Reports said 23 of the 28 samples tested exceeded their safety levels.
"All of the samples that we tested had detectable levels of either cadmium or lead," Rogers said.
Cadmium found in soil can infiltrate coco plants and lead contamination can happen in processing chocolate.
The CDC said long-term exposure to heavy metals can cause a variety of health issues including brain damage and kidney and heart disease.
This is of special concern for young children and pregnant women.
"It can affect different types of mental issues with children and fetuses of pregnant women," Rogers said.
The research tested different brands including organic varieties.
Higher concentrations of cacao used to make dark chocolate were linked to higher metal levels.
"Just eating one ounce daily would expose you to enough heavy metals to be concerning," Rogers said.
A statement from the National Confectioners Association said "standards cited in the Consumer Reports study are not food safety standards. The products cited in this study are in compliance with strict quality and safety requirements."
The FDA said the presence of cadmium and lead in chocolate is well documented and is not dangerous for most people if consumed occasionally.
The Confectioners Association in August released research showing ways that lead and cadmium in chocolate could be reduced, including having cocoa farmers plant new tree stock.