Topline
Many dark chocolate and cocoa products sold across the country contain levels of toxic heavy metals that exceed food safety guidelines, according to new research published Wednesday—and while the food industry and researchers involved said the findings should not stop people from eating chocolate, experts said it warrants further scrutiny.
Key Facts
Researchers from George Washington University and ConsumerLab, a company that tests foods and supplements, examined the amount of lead, cadmium and arsenic in more than 70 dark chocolate and cocoa products purchased from retailers including Amazon, GNC and Whole Foods Market over 8 years.
Their results, published in the peer reviewed journal Frontiers of Nutrition, revealed 43% of products exceeded acceptable levels of lead per serving and 35% exceeded acceptable levels of cadmium, according to California’s stringent food guidelines.
The state’s guidelines are often used by researchers as a conservative safety benchmark when investigating heavy metal contamination in foods, as the Food and Drug Administration does not set limits for toxins including cadmium and arsenic and for others like lead may only do so for specific products like candy or baby food.
None of the products tested exceeded California’s maximum level for arsenic and almost all products—70 out of 72, or 97%—had levels of lead that fell below FDA limits for the metal.
The researchers said the heavy metals found in the chocolate are unlikely to “pose any appreciable risk” when consumed as a single serving but could be “potentially problematic” if multiple servings are consumed or they are eaten with other products that may contain heavy metals such as teas or spices.
The study is the latest research to suggest some popular chocolate brands contain heavy metals, including studies by Consumer Reports.
In an emailed statement, the National Confectioners Association told Forbes “chocolate and cocoa are safe to eat and can be enjoyed as treats as they have been for centuries,” adding that “food safety and product quality remain” the organization’s “highest priorities.”
What Brands Of Chocolate Contain Heavy Metals?
It’s not clear what brands of dark chocolate and cocoa products had what levels of heavy metals in the study as the researchers intentionally left the information out of the study. The products tested are likely to be well known to consumers, however, and the researchers said their aim was to assess heavy metal contamination in “the most popular cocoa-containing consumer products each year for several years to assess trends,” using consumer surveys to assess popularity.
Should I Stop Eating Chocolate?
In short, no. According to the researchers, the amount of heavy metals found in the chocolate studied is unlikely to be “biologically significant” on its own, especially as most people are likely to consume the products relatively infrequently and in small amounts. The findings do suggest a need for better food standards and guidelines when it comes to heavy metal contamination, they said. “Enhanced surveillance may be warranted,” as well, the researchers added, particularly given the presence of outliers in the study with particularly high levels of contamination. Further research into the potential impact of multiple streams of food contamination should also be conducted, the researchers said, as it’s possible there may be “additive exposure” that is problematic from multiple food sources.
Can I Avoid Heavy Metal Exposure In Food?
Also no. “You actually cannot avoid exposure to heavy metals in the diet,” Leigh Frame, the study’s lead author and director of integrative medicine at George Washington University School of Medicine and Health Sciences, told NBC News. Heavy metals can naturally enter foods from soil and water in the growing process or at various points during packaging, drying, processing and transportation. Cocoa, rice, cereals, potatoes and tobacco can take up cadmium from the soil, for example, and lead can be introduced in the production of cocoa products. Small levels are not always dangerous and can be excreted from the body such as through sweat and urine but high levels can become concentrated in the body where they can cause damage. Cadmium is a carcinogen at high levels—it can cause cancer—and can damage most of the body’s systems, including the lungs, bones and kidneys. The CDC says there are no safe levels of lead in the blood for children and the metal can interfere with the developing brain and damage the nervous system. However, “it’s really not about avoiding them; it’s about making sure you’re not getting too much,” Frame said. Eating a diverse diet is one way of avoiding exposure, as is limiting consumption of products known to contain relatively high levels. Frame added that “better quality control practices during harvesting and manufacturing may help eliminate the problem” too, as well as better surveillance.
Surprising Fact
Organic products were more likely to have higher levels of cadmium and lead, the researchers found. “More striking, the number of trade certifications (e.g., Non-GMO, Fairtrade) did not significantly alter the levels of heavy metals found among products surveyed,” the researchers wrote.
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