Research has found that many dark chocolate bars contain unsafe levels of cadmium and lead, two heavy metals linked to a host of health problems in children and adults.

Dark chocolate is created from cocoa solids, cocoa butter, sugar, and occasionally milk or additional components. It is often advertised as a healthier option that milk chocolate due to its reduced sugar content.

It has a deeper colour and a richer, more powerful flavour than milk chocolate, which contains more sugar and milk solids. Dark chocolate has been linked to improvements in heart health, brain function, and blood pressure.

Dark chocolate has a lot of antioxidants, which might help protect your body from free radicals. Brands such as Lindt, Ghirardelli and Hershey’s manufacture many types of dark chocolate bars which are available in the UK and America.

Scientists from Consumer Reports, an American nonprofit consumer organisation similar to Which?, recently measured the amount of heavy metals in 28 dark chocolate bars – and detected cadmium and lead in all of them.

Lead and cadmium are hazardous heavy metals that, if consumed or breathed in, may be damaging to human health. Both metals may build in the body and produce a range of health issues over time.

Consumer Reports found that the following bars exceeded California’s maximum acceptable dosage level (MADL) of 4.1 micrograms for cadmium:

  • Alter Eco Organic Dark Chocolate Classic Blackout 85% Cacao: cadmium levels reaching 204% of the maximum acceptable dosage level
  • Beyond Good Organic Pure Dark Chocolate 70% Cocoa: 112%
  • Beyond Good Organic Pure Dark Chocolate 80% Cocoa: 138%
  • Dove Promises Deeper Dark Chocolate 70% Cacao: 112%
  • Equal Exchange Organic Extra Dark Chocolate 80% Cacao: 120%
  • Lindt Excellence Dark Chocolate 70% Cocoa: 116%
  • Pascha Organic Very Dark Dark Chocolate 85% Cacao: 253%
  • Scharffen Berger Extra Dark Chocolate 82% Cacao: 136%

Consumer Reports testing found too high levels of lead based on California’s maximum acceptable dosage level of 0.5 micrograms in the following chocolate bars:

  • Chocolove Strong Dark Chocolate 70% Cocoa: lead levels reaching 152% of California’s maximum acceptable dosage level
  • Chocolove Extreme Dark Chocolate 88% Cocoa: 240%
  • Endangered Species Bold + Silky Dark Chocolate 72% Cocoa: 181%
  • Godiva Signature Dark Chocolate 72% Cacao: 146%
  • Hershey’s Special Dark Mildly Sweet Chocolate: 265%
  • Hu Organic Simple Dark Chocolate 70% Cacao: 210%
  • Lily’s Extra Dark Chocolate 70% Cocoa: 144%
  • Lindt Excellence Dark Chocolate 85% Cocoa: 166%
  • Tony’s Chocolonely Dark Chocolate 70% Cocoa: 134%
  • Trader Joe’s Dark Chocolate 72% Cacao: 192%

The state of California prevents food products from having more than 0.5 micrograms of lead and 4.1 micrograms of cadmium.

Cadmium can be harmful to human health if it is inhaled or ingested in large amounts, as it can accumulate in the body and cause health problems such as kidney damage and bone loss.

Cadmium has been determined as a cancer-causing agent, according to the Centers for Disease Control.

Lead can also be found in certain foods, particularly those that are grown in soil that is contaminated with lead or that are stored in containers that contain lead.

Consuming large amounts of lead can lead to health problems, including damage to the brain, nerves, and kidneys. Children are especially vulnerable to the effects of lead, as their bodies are still developing and they may be more susceptible to the toxic effects of the metal.

Lead and cadmium can lead to high blood pressure, suppression of your immune system, and damage to your kidneys, nervous system, or reproductive organs. Foods such as carrots and spinach also have at least small amounts of such heavy metals.

If you think you may have consumed lead or cadmium, it is important to contact a healthcare provider for further evaluation and treatment.

In response to the research, the National Confectioners Association provided the following statement: “Chocolate and cocoa are safe to eat and can be enjoyed as treats as they have been for centuries. The California Office of Environmental Health Hazard Assessment (OEHHA) standards cited in the Consumer Reports study are not food safety standards.”

Of 28 chocolate bars tested, only 5 had cadmium and lead levels that were below the California maximum acceptable dosage levels:

  • Ghirardelli Intense Dark Chocolate 86% Cacao: 36% for lead and 39% for cadmium
  • Ghirardelli Intense Dark Chocolate Twilight Delight 72% Cacao: 61% for lead and 96% for cadmium
  • 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
  • Valrhona Abinao Dark Chocolate 85% Cacao: 63% for lead and 73% for cadmium

In fact, the Hershey Company is being sued for allegedly failing to disclose the presence of lead and cadmium in several of its dark chocolate bars in a proposed class action, brought by Christopher Lazazzaro of New York.

This follows previous research done in August of 2022 by the nonprofit environmental accountability organisation As You Sow which discovered that heavy metals enter cocoa mostly through polluted soil.

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