Dangerous heavy metals found in popular dark chocolate bars: Study

Be careful the next time you crave that dark chocolate bar.

The organization, Consumer Reports, says two dangerous heavy metals, lead and cadmium, showed up in tests of 28 dark chocolate bars, including bars of some popular brands.

According to Consumer Reports, for 23 of the bars, eating just an ounce a day could put an adult over acceptable levels for at least one of those metals. Five of the bars were above those levels for both cadmium and lead.

But that doesn't mean you have to swear off chocolate entirely. Here are ones considered safer, and some that had the most levels of heavy metals:

"Safer choices" – Five bars that had lower levels

  • Mast Organic Dark Chocolate 80% Cocoa: 14% for lead and 40% for cadmium.
  • Taza Chocolate Organic Deliciously Dark Chocolate 70% Cacao: 33% for lead and 74% for cadmium.
  • Ghirardelli Intense Dark Chocolate 85% Cacao: 36% for lead and 39% for cadmium.
  • Ghirardelli Intense Dark Chocolate Twilight Delight 72% Cacao: 61% for lead and 96% for cadmium.
  • Valrhona Abinao Dark Chocolate 85% Cacao: 63% for lead and 73% for cadmium.
Sign with logo for iconic San Francisco gourmet chocolate company Ghirardelli at the company's factory and headquarters in San Leandro, California, September 10, 2018. (Photo by Smith Collection/Gado/Getty Images)

Sign with logo for iconic San Francisco gourmet chocolate company Ghirardelli at the company's factory and headquarters in San Leandro, California, September 10, 2018. (Photo by Smith Collection/Gado/Getty Images)

Eight bars listed as high in cadmium

  • Beyond Good Organic Pure Dark Chocolate 70% Cocoa: 112% for cadmium.
  • Beyond Good Organic Pure Dark Chocolate 80% Cocoa: 138% for cadmium.
  • Equal Exchange Organic Extra Dark Chocolate 80% Cacao: 120% for cadmium.
  • Lindt Excellence Dark Chocolate 70% Cocoa: 116% for cadmium.
  • Scharffen Berger Extra Dark Chocolate 82% Cacao: 136% for cadmium.
  • Alter Eco Organic Dark Chocolate Classic Blackout 85% Cacao: 204% for cadmium.
  • Pascha Organic Very Dark Dark Chocolate 85% Cacao: 253% for cadmium.
  • Dove Promises Deeper Dark Chocolate 70% Cacao: 112% for cadmium.
A logo of Lindt, is a Swiss chocolatier and confectionery company, seen in Sofia city center. On October 7, 2020, in Sofia, Bulgaria. (Photo by Artur Widak/NurPhoto via Getty Images)

A logo of Lindt, is a Swiss chocolatier and confectionery company, seen in Sofia city center. On October 7, 2020, in Sofia, Bulgaria. (Photo by Artur Widak/NurPhoto via Getty Images)

Ten bars listed as high in lead

  • Tony’s Chocolonely Dark Chocolate 70% Cocoa: 134% for lead.
  • Lily’s Extra Dark Chocolate 70% Cocoa: 144% for lead.
  • Godiva Signature Dark Chocolate 72% Cacao: 146% for lead.
  • Chocolove Strong Dark Chocolate 70% Cocoa: 152% for lead.
  • Lindt Excellence Dark Chocolate 85% Cocoa: 166% for lead.
  • Endangered Species Bold + Silky Dark Chocolate 72% Cocoa181% for lead.
  • Trader Joe’s Dark Chocolate 72% Cacao: 192% for lead.
  • Hu Organic Simple Dark Chocolate 70% Cacao: 210% for lead.
  • Chocolove Extreme Dark Chocolate 88% Cocoa: 240% for lead.
  • Hershey’s Special Dark Mildly Sweet Chocolate: 265% for lead.
Photo credit: Amazon.com

Photo credit: Amazon.com

Photo credit: Amazon.com

Photo credit: Amazon.com

Five bars listed as high in both lead and cadmium

  • Theo Organic Pure Dark 70% Cocoa: 120% for lead and 142% for cadmium.
  • Trader Joe’s The Dark Chocolate Lover’s Chocolate 85% Cacao: 127% for lead and 229% for cadmium.
  • Theo Organic Extra Dark Pure Dark Chocolate 85% Cocoa: 140% for lead and 189% for cadmium.
  • Lily’s Extremely Dark Chocolate 85% Cocoa: 143% for lead and 101% for cadmium.
  • Green & Black’s Organic Dark Chocolate 70% Cacao: 143% for lead and 181% for cadmium.
Photo credit: Amazon.com

Photo credit: Amazon.com

Photo credit: Amazon.com

Photo credit: Amazon.com

The two heavy metals linked to a host of health problems in children and adults. The danger is greatest for pregnant people and young children because the metals can cause developmental problems and affect brain development, said Tunde Akinleye, the Consumer Reports food safety researcher who led the project. 

They say consistent, long-term exposure to even small amounts of heavy metals can lead to a variety of health problems.

Better ways to eat dark chocolate

Experts say that by being mindful of the risks, you can still enjoy dark chocolate while minimizing the potential harms:

  • Choose dark chocolates with the lowest levels of heavy metals.
  • Treat chocolate as a treat.
  • Try dark chocolates with lower cacao percentages.
  • Alternate with milk chocolate.
  • Don’t assume organic dark chocolates are safer.
  • Don’t give kids much dark chocolate.
  • Think about your total chocolate consumption.
  • Eat a well-rounded diet.
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