New Study Finds Heavy Metals Like Lead In US Dark Chocolate Products

A new study has found that many dark chocolate products currently on the US market are contaminated with toxic heavy metals like lead and cadmium.

George Washington University researchers analyzed 72 consumer cocoa products, including dark chocolate, every other year over an eight-year period for lead, cadmium, and arsenic.

Their new study, published by Frontiers Nutrition, found that 43 percent of the products exceeded the maximum allowable dose for lead, 35 percent exceeded the maximum allowable dose for cadmium, and organic showed higher levels than non-organic.

None of the products exceeded the maximum allowable dose for arsenic.

Leigh Frame, the director of integrative medicine and associate professor of clinical research and leadership, and Jacob Hands, a medical student researcher in the Frame-Corr Lab – both of George Washington’s School of Medicine and Health Sciences – led the study.

The team partnered with ConsumerLab, a company that independently tests and evaluates health and nutrition products, and purchased the chocolate for the study through third-party online retailers like Amazon and iHerb, physical retailers like GNC and Whole Foods, and manufacturer and distributor websites. The tested brands are not listed in the study.

Lead found in other US food products

Photo shows a small brown dish of cocoa powder alongside cocoa beans and pieces of dark chocolate — Adobe Stock The study’s authors said that in moderation, risk is still low, but the results warrant further investigation

Cadmium can cause cancer, and it can also negatively impact the cardiovascular, neurological, respiratory, and reproductive systems.

According to the US Food and Drug Administration (FDA), “there is no known safe level of exposure to lead,” and ingesting even a small amount can cause negative health outcomes. But despite this, the extremely toxic heavy metal keeps appearing in American foods.

In the latter half of 2023, lead-contaminated applesauce pouches caused multiple cases of lead poisoning before being recalled. In March 2024, the FDA highlighted elevated levels of lead in certain ground cinnamon products and advised the public not to purchase them.

Then, in April, the Consumer Reports Advocacy division called on the USDA to remove Kraft Heinz Lunchables from the federal school dinners program after they were found to contain “relatively high levels of lead and cadmium” and “concerning levels” of harmful chemicals.

“We all love chocolate but it’s important to indulge with moderation as with other foods that contain heavy metals including large fish like tuna and unwashed brown rice,” said Frame of the new study’s results on cocoa products. “While it’s not practical to avoid heavy metals in your food entirely, you must be cautious of what you are eating and how much.”