A new study found that dark chocolate from various popular brands contains unsafe levels of heavy metals. Findings published by Consumer Reports show that many dark chocolate bars contain cadmium and lead, which can lead to many different health problems. This may be an industry-wide problem that needs to be addressed.
Scientists working with Consumer Reports tested 28 different chocolate bars for heavy metals and found cadmium and lead in all of them. The test subjects ranged from global brands like Dove and Ghirardelli to newer brands like Alter Eco and Mast. Among these products, 23 of them contained more cadmium and lead in a one-ounce serving than public health authorities would approve for an adult to consume in a day, while five were above those levels. The scientists noted that exposure to these metals is more dangerous for pregnant people and young children because they can impact brain development, among other processes.
However, lead researcher Tunde Akinleye warned that "there are risks for people of any age" in consuming this much metal. While the dangers of lead are often emphasized when it comes to children, adults consuming the substance can experience problems with their nervous systems,s, immune systems and reproductive systems. Common complications include hypertension and kidney damage.
The article included five recommendations for dark chocolate products that are safer than their competitors, based on their testing. They recommended Mast's "Organic Dark Chocolate 80 percent Cocoa," Taza Chocolate's "Organic Deliciously Dark Chocolate 70 percent Cacao," Valrhona's "Abinao Dark Chocolate 85 percent Cacao," Ghirardelli's "Intense Dark Chocolate 86 percent Cacao" and Ghirardelli's "Intense Dark Chocolate Twilight Delight 72 percent Cacao." You can find photos of these products on the CR site, along with photos of the products that tested higher for heavy metals.
These comparisons related mostly to the recommendations for daily exposure to heavy metals, and market researchers confirmed to Consumer Reports that most people do not eat dark chocolate on a daily basis. However, Akinleye's team warned that even occasional exposure can be risky – especially when coupled with the risk of other unknown exposures from other sources. For example, sweet potatoes, spinach and carrots have been found to contain high levels of cadmium.
Akinleye said that he is confident this problem can be corrected, pointing out that the levels of lead and cadmium were relatively low in five of their test subjects. He said: "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."