PHILADELPHIA (CBS) — Certain types of dark chocolate, long considered healthier than other sweet treats, contain potentially dangerous amounts of heavy metals, according to a study released Thursday by Consumer Reports.
Scientists at a nonprofit organization recently measured the amount of heavy metals in 28 popular brands of dark chocolate bars and found cadmium and lead in all of them. Consuming just one ounce per day for 23 of the alloys will raise an adult’s levels of at least one of the metals that can be harmful, CR said. Five of the bars were above those levels for both cadmium and lead.
Long-term exposure to even small amounts of heavy metals can lead to a variety of health problems, including developmental and brain problems in young children, experts say.
“However, there are risks for people of any age,” Tunde Akinli, a CR food safety researcher who led the test, said in a statement. In adults, frequent exposure to lead can lead to nervous system problems, hypertension, immune system suppression, kidney damage and reproductive problems, he noted.
While most 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 produce products with lower amounts of heavy metals and for consumers to find safer products that they enjoy,” Akinley said.
In determining the risks for the chocolate it tested, CR used California’s maximum allowable dose of 0.5 micrograms for lead and 4.1 micrograms for cadmium because there are no federal limits.
CR found that one ounce of Hershey’s Special Dark Mildly Sweet chocolate contained 265% more lead than California allows, and Trader Joe’s Dark Chocolate 72% cocoa contained 192% more.
Trader Joe’s did not immediately respond to a request for comment.
A spokeswoman for Hershey’s deferred comment to the National Confectioners Association. In an emailed statement, the trade group objects to CR’s use of levels set by California, noting that the state does not set federal food safety standards.
“The products identified in this study meet strict quality and safety standards,” a spokesperson for the group said in an email to CBS MoneyWatch. “Food safety and product quality remain our highest priorities, and we remain committed to being transparent and socially responsible.”
The Confectioners Association released research in August showing ways to reduce lead and cadmium in chocolate, including getting cocoa farmers to plant new trees.
According to CR findings, the safest choices are:
- Mast Organic dark chocolate 80% cocoa. CR found that the ounce contained 14% less lead and 40% less cadmium than California’s allowable limits.
- Taza Chocolate Organic Deliciously Dark Chocolate 70% cocoa contained 33% less lead and 74% less cadmium.
- Ghirardelli Intense Dark Chocolate 86% cocoa contained 36% less lead and 39% less cadmium.
- Ghirardelli Intense Dark Chocolate Twilight Delight. Lead content was 61% below the permissible level and cadmium was 96% below the permissible limit.
- Valrhona Abinao dark chocolate 85% cocoa. Lead 63% and cadmium 73% low.