PHILADELPHIA (CBS) — Long viewed as healthier than other sweet treats, some types of dark chocolate contain potentially dangerous amounts of heavy metals, according to research released Thursday by Consumer Reports.
Researchers at the nonprofit recently measured the amount of heavy metals in 28 popular brands of dark chocolate bars and found cadmium and lead in all of them. For 23 of the bars, consuming just one ounce a day would put an adult above a level for at least one of the metals that could be harmful, CR said. Five of the rods were above these levels for both cadmium and lead.
Long-term exposure to even small amounts of heavy metals can lead to a range of health problems, including developmental and brain development problems in young children, experts say.
“But there are risks to people of all ages,”[ads1]; Tunde Akinleye, the CR food safety researcher who led the testing, said in a statement. Frequent exposure to lead in adults can lead to nervous system problems, hypertension, immune system suppression, kidney damage and reproductive problems, he noted.
While most of the chocolate bars tested contained levels of lead, cadmium or both, five had relatively low levels of both metals, CR found.
“It shows that it is possible for companies to make products with lower amounts of heavy metals – and for consumers to find safer products that they like,” Akinleye said.
In determining the risk of the chocolate it tested, CR used California’s maximum allowable dose levels of 0.5 micrograms for lead and 4.1 micrograms for cadmium, since there are no federal limits.
CR found that one ounce of Hershey’s Special Dark Mildly Sweet Chocolate contained lead 265% above what California allows, and Trader Joe’s Dark Chocolate 72% Cacao contained 192% more.
Trader Joe’s did not immediately respond to a request for comment.
A spokesperson for Hershey’s reached out to the National Confectioners Association for comment. In an email, the trade group objected to CR’s use of levels set by California, noting that the state does not set federal standards for food safety.
“The products cited in this study comply with strict quality and safety requirements,” a spokesperson for the group stated in an email to CBS MoneyWatch. “Food safety and product quality remain our highest priorities, and we remain dedicated to being transparent and socially responsible.”
In August, the confectioners’ association released research showing ways to reduce lead and cadmium in chocolate, including allowing cocoa farmers to plant new trees.
According to CR’s findings, the safer choices are:
- Mast Organic dark chocolate 80% cocoa. CR found one ounce contained 14% less lead and 40% less cadmium than California’s allowable limits.
- Taza Chocolate Organic Delicious Dark Chocolate 70% Cacao contained 33% less lead and 74% less cadmium.
- Ghirardelli Intense Dark Chocolate 86% Cacao contained 36% less lead and 39% less cadmium.
- Ghirardelli Intense Dark Chocolate Twilight Delight. Contained lead was 61% below the permitted level and cadmium 96% below the permitted limit.
- Valrhona Abinao dark chocolate 85% cocoa. Lead 63% and cadmium 73% below.