TAMPA, Fla. (WFLA) — Dark chocolate, that sweet and savory staple for millions across the world, may have a dark side, according to research released by Consumer Reports.
Scientists at the nonprofit advocacy organization recently took a look at 28 popular brands of dark chocolate bars, including products from Dove, Hershey’s, and Traders Joe’s, and found traces of “dangerous heavy metals” in all of them.
Researchers found the dark chocolate bars contained cadmium and lead—two heavy metals linked to a host of health problems in children and adults.
Long-term exposure to even small amounts of heavy metals can lead to a variety of health problems and poses the greatest risk for pregnant people and young children because the metals can cause developmental problems, affect brain development, and lead to lower IQ, according to Tunde Akinleye, the Consumer Report food safety researcher who led the study.
“But there are risks for people of any age,” Akinleye said. “Frequent exposure to lead in adults, for example, can lead to nervous system problems, hypertension, immune system suppression, kidney damage, and reproductive issues.”
For the study, researchers 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 one ounce per day would put an adult over a level that public health authorities say may be harmful for at least one of those heavy metals.
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,” Akinleye said.
Consumer Reports used California’s maximum allowable dose level (MADL) for lead (0.5 micrograms) and cadmium (4.1mcg) because there are no federal limits for the amount of lead and cadmium most foods can contain. The organization said it chose California’s dose level because it is the most protective available.
Shown below are the percentages of the MADL supplied in an ounce of each chocolate:
Safer choices
| Brand | Product Name | Lead Amount | Cadmium Amount |
| Mast | Organic Dark Chocolate 80% Cocoa | 14% | 40% |
| Taza Chocolate | Organic Deliciously Dark Chocolate 70% Cacao | 33% | 74% |
| Chirardelli | Intense Dark Chocolate 86% Cacao | 36% | 39% |
| Ghirardelli | Intense Dark Chocolate Twilight Delight 72% Cacao | 61% | 96% |
| Valrhona | Abinao Dark Chocolate 85% Cacao | 63% | 73% |
High in cadmium
| Brand | Product Name | Lead Amount | Cadmium Amount |
| Beyond Good | Organic Pure Dark Chocolate 70% Cocoa | 42% | 112% |
| Beyond Good | Organic Pure Dark Chocolate 80% Cocoa | 42% | 138% |
| Equal Exchange | Organic Extra Dark Chocolate 80% Cacao | 45% | 120% |
| Lindt | Excellence Dark Chocolate 70% Cocoa | 48% | 116% |
| Scharffen Berger | Extra Dark Chocolate 82% Cacao | 49% | 136% |
| Alter Eco | Organic Dark Chocolate Classic Blackout 85% Cacao | 49% | 204% |
| Pascha | Organic Very Dark Dark Chocolate 85% Cacao | 68% | 253% |
| Dove | Promises Deeper Dark Chocolate 70% Cacao | 74% | 112% |
High in Lead
| Brand | Product Name | Lead Amount | Cadmium Amount |
| Tony’s | Chocolonely Dark Chocolate 70% Cocoa | 134% | 28% |
| Lily’s | Extra Dark Chocolate 70% Cocoa | 144% | 42% |
| Godiva | Signature Dark Chocolate 72% Cacao | 146% | 25% |
| Chocolove | Strong Dark Chocolate 70% Cocoa | 152% | 60% |
| Lindt | Excellence Dark Chocolate 85% Cocoa | 166% | 80% |
| Endangered Species | Bold + Silky Dark Chocolate 72% Cocoa | 181% | 31% |
| Trader Joe’s | Dark Chocolate 72% Cacao | 192% | 36% |
| Hu | Organic Simple Dark Chocolate 70% Cacao | 210% | 56% |
| Chocolove | Extreme Dark Chocolate 88% Cocoa | 240% | 83% |
| Hershey’s | Special Dark Mildly Sweet Chocolate | 265% | 30% |
High in both lead and cadmium
| Brand | Product Name | Lead Amount | Cadmium Amount |
| Theo | Organic Pure Dark 70% Cocoa | 120% | 142% |
| Trader Joe’s | The Dark Chocolate Lover’s Chocolate 85% Cacao | 127% | 229% |
| Theo | Organic Extra Dark Pure Dark Chocolate 85% Cocoa | 140% | 189% |
| Lily’s | Extremely Dark Chocolate 85% Cocoa | 143% | 101% |
| Green & Black’s | Organic Dark Chocolate 70% Cacao | 143% | 181% |
While the report showed some products with relatively high levels of heavy metals, dark chocolate is widely known for its potential health benefits, thanks to studies that suggest its rich supply of antioxidants may improve heart health and other conditions. Dark chocolate also contains a lower level of sugar.
