Consumer Reports found dangerous heavy metals in chocolate from Hershey’s, Theo, Trader Joe’s and other popular brands. Here are the ones that had the most, and some that are safer.

December 15, 2022

By Kevin Loria

Data visualizations by Andy Bergmann

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For many of us, chocolate is more than just a tasty treat. It’s a mood lifter, an energy booster, a reward after a tough day, a favorite holiday gift. 

People also choose dark chocolate in particular for its potential health benefits, thanks to studies that suggest its rich supply of antioxidants may improve heart health and other conditions, and for its relatively low levels of sugar. In fact, more than half of people in a recent survey from the National Confectioners Association described dark chocolate as a “better for you” candy.

But there’s a dark side to this “healthier” chocolate. Research has found that some dark chocolate bars contain cadmium and lead—two heavy metals linked to a host of health problems in children and adults. 

The chocolate industry has been grappling with ways to lower those levels. To see how much of a risk these favorite treats pose, Consumer Reports scientists recently measured the amount of heavy metals in 28 dark chocolate bars. They detected cadmium and lead in all of them.

Heavy Metals in Dark Chocolate

CR tested a mix of brands, including smaller ones, such as Alter Eco and Mast, and more familiar ones, like Dove and Ghirardelli. 

For 23 of the bars, eating just an ounce a day would put an adult over a level that public health authorities and CR’s experts say may be harmful for at least one of those heavy metals. Five of the bars were above those levels for both cadmium and lead.

That’s risky stuff: Consistent, long-term exposure to even small amounts of heavy metals can lead to a variety of health problems. The danger is greatest for pregnant people and young children because the metals can cause developmental problems, affect brain development, and lead to lower IQ, says Tunde Akinleye, the CR food safety researcher who led this testing project. 

“But there are risks for people of any age,” he says. Frequent exposure to lead in adults, for example, can lead to nervous system problems, hypertension, immune system suppression, kidney damage, and reproductive issues. While most people don’t eat chocolate every day, 15 percent do, according to the market research firm Mintel. Even if you aren’t a frequent consumer of chocolate, lead and cadmium can still be a concern. It can be found in many other foods—such as sweet potatoes, spinach, and carrots—and small amounts from multiple sources can add up to dangerous levels. That’s why it’s important to limit exposure when you can.

Still, you don’t need to swear off chocolate entirely, Akinleye says. He adds that while most of the chocolate bars in CR’s tests had concerning levels of lead, cadmium, or both, five of them were relatively low in both. “That shows it’s possible for companies to make products with lower amounts of heavy metals—and for consumers to find safer products that they enjoy,” he says.

And in addition to choosing your dark chocolates wisely, there are a number of other steps you can take to continue enjoying chocolate safely.