Do You Need to Worry About Heavy Metals in Dark Chocolate?

There’s good news for dark chocolate lovers: According to a recent study, this sweet treat poses no health risks to adults.

For the study, published June 6 in International food research, scientists at Tulane University tested more than a hundred dark and milk chocolate bars sold in the United States for levels of heavy metals, including toxic metals like lead and cadmium. They concluded that the products are safe for adults and a small minority may pose a slight risk to young children, but only if consumed in large quantities.

These results come one year after the publication of an article by Consumer Reports have shown harmful levels of lead and cadmium in some brands of dark chocolate, raising concerns about the safety of consuming dark chocolate.

“What we found is that it is completely safe to consume both dark chocolate and milk chocolate,” lead author Tewodros Godebo, PhD, assistant professor of environmental health sciences at Tulane University School of Public Health and Tropical Medicine, said in a press release.

Here’s what you need to know about the study results, what previous research has shown, and what experts not involved in the study think about the safety of eating dark chocolate.

For the Consumer Reports In the study, researchers tested 48 products across five categories: cocoa powder, chocolate chips, milk chocolate bars, dark chocolate bars, and mixes for brownies, chocolate cakes, and hot chocolate. They focused on lead and cadmium, metals that can impact the brain and nervous system, with children particularly vulnerable to symptoms.

The researchers found that dark chocolates contained higher levels of heavy metals than their milk chocolate counterparts. Every dark chocolate bar tested contained detectable amounts of lead and cadmium, with 71 percent of them exceeding California’s maximum allowable dose levels for lead, cadmium, or both.

The researchers used the California standard because there is no federal limit on the amount of lead and cadmium that most foods can contain. The maximum authorized daily dose for lead is 0.5 micrograms (mcg) and 4.1 mcg for cadmium.

The research was based on a Consumer Reports 2022 study, which found that 82% of dark chocolate bars tested had lead or cadmium levels above the California threshold.

Cadmium can end up in dark chocolate because cocoa beans absorb it from contaminated soil, James E. Rogers, PhD, director and acting head of product safety testing at Consumer Reportssaid previously Health. Lead can enter cocoa beans after harvest, potentially from dust and soil, while the beans dry outdoors.

The Tulane team analyzed samples of 155 dark and milk chocolates from different brands sold in the United States, including well-known brands like Dove, Ghirardelli, Hershey, Lindt and Trader Joe’s. Each has been tested for the presence of 16 heavy metals, ranging from the essential, like copper, iron, and zinc, to the harmful, like lead and cadmium.

The researchers then calculated the risk of eating one ounce of chocolate per day, which equates to more than two candy bars per week.

They found that only one brand of dark chocolate – Lok Dark Chocolate from Colombia – exceeded the European Union limit of 800 mcg per kilogram (mcg/kg) of cadmium in bars containing more than 50% cocoa.

Four dark chocolate bars contained levels of cadmium that researchers deemed unsafe for children weighing up to 33 pounds, the weight of an average three-year-old in the United States. The bars were:

• Lok Dark Chocolate
• Marou
• Vivio Foods Mexican Organic Cocoa Powder
• Pascha Dark Chocolate Chips from Peru

Two chocolate bars, Napolitains Dark and Blanxart, had lead levels above the California standard of 150 mcg/kg for dark chocolates. However, researchers found that they were not likely to harm adults or children.

“For adults, there is no health risk associated with eating dark chocolate,” Godebo said. “While there is a slight risk to children in four of the 155 chocolate bars sampled, it is not common to see a 3-year-old regularly consuming more than two chocolate bars per week.”

The study also found that dark chocolate contained high levels of important nutrients like copper, iron, manganese, magnesium and zinc. Some bars even contained more than 50% of the daily nutritional needs of children and adults.

“Not only do (dark chocolate) contain these essential minerals, but they can potentially reduce the absorption of toxic metals in the gut since these metals compete for the same site,” Godebo said. “While two previous studies in the United States examined the presence of lead and cadmium in chocolate, this study used the largest sample, expanded the scope of testing to 16 metals, and included a toxic metal risk assessment that explained the nutritional contribution of chocolate. essential minerals.

Serving size is a factor to consider when assessing the risk of consuming dark chocolate, said Jamie Alan, PharmD, PhD, associate professor of pharmacology and toxicology at Michigan State University. Health. “If people regularly eat more than 30 grams of dark chocolate per day,” she explained, the results of the most recent study “may not be applicable.”

However, it’s unlikely that most adults “consume enough dark chocolate for these potentially harmful substances to cause a problem,” said Deborah Cohen, DCN, associate professor in the department of clinical and preventive nutrition sciences at Rutgers University School of Health Professions. Health.

She added that dark chocolate also has benefits, including being rich in plant chemicals called flavanols, which can help protect the heart.

“Dark chocolate contains up to two to three times more flavanol-rich cocoa solids than milk chocolate,” she said. “The flavanols in chocolate may increase insulin sensitivity in short-term studies; in the long term, this may reduce the risk of diabetes.”

But Cohen stressed that you shouldn’t start thinking of dark chocolate as comparable to fruits and vegetables. “Vegetables contain many other important nutrients: antioxidants, phytochemicals and fiber,” she said. “However, if you’re craving a little chocolate every now and then, a bite or two or an ounce or two won’t hurt.”