Dark chocolate is that rare sweet treat with health benefits, potentially helping to reduce inflammation and supporting heart health thanks to its powerful antioxidants, nutritionists say.
But dark chocolate may also contain two heavy metals harmful to health, Consumer Reports warns in an investigation published Thursday, Dec. 15.
When the organization tested 28 dark chocolate bars from a variety of brands, it found cadmium and lead in all of them, according to the report. The products didn’t have extremely high levels of the heavy metals, but most had levels high enough to be a health concern, says James Rogers, director of food safety research and testing at Consumer Reports.
The National Confectioners Association, the industry trade group, counters that chocolate and cocoa are safe to eat.
“(They) can be enjoyed as treats as they have been for centuries,” Christopher Gindlesperger, a spokesperson for the association, says in a statement to TODAY.com.
“The products cited in this study are in compliance with strict quality and safety requirements.”
Cadmium is a natural element found in the soil. It’s considered a cancer-causing agent, with exposure to low levels of it over time also potentially causing kidney disease and fragile bones, according to the Centers for Disease Control and Prevention.
Lead, also a naturally occurring element, can seriously harm a child’s health and even lead to brain damage, the CDC warned. Adults exposed over time may be at risk for high blood pressure, heart disease and kidney disease.
Rogers says he was surprised every brand tested had detectable levels of the two heavy metals.
“There is a health halo, so there are people who eat dark chocolate every day for the health benefits of it, and we thought it was important to take a look at that to say: Is eating dark chocolate every day healthy?” Rogers tells TODAY.com.
“On the one hand it is, from the antioxidants that are said to be in dark chocolate. But on the other hand, if you’re eating this dark chocolate that has heavy metals in it, our findings are suggesting no, you should not eat it every day.”
Using a standard set by California, the investigation found that for 23 of the bars tested, eating 1 ounce a day would put an adult over the level that Consumer Reports experts considered to be potentially harmful for at least one of the heavy metals.
Five of the bars tested were above those levels for both cadmium and lead, according to Consumer Reports. They included:
- Theo Organic Pure Dark 70% Cocoa
- Theo Organic Extra Dark Pure Dark Chocolate 85% Cocoa
- Trader Joe’s The Dark Chocolate Lover’s Chocolate 85% Cacao
- Lily’s Extremely Dark Chocolate 85% Cocoa
- Green & Black’s Organic Dark Chocolate 70% Cacao
TODAY.com reached out to those manufacturers for comment. Mondelēz Global, the parent company of Green & Black’s, directed inquiries to the National Confectioners Association.
The Hershey Company, whose brands include Lily's, said food safety is paramount at the company. "We source our ingredients and manufacture our products in accordance with a robust food safety plan," spokesperson Todd Scott said in a statement.
The other companies did not immediately respond.
The full results of the investigation can be found on Consumer Reports' website.
As it evaluated the chocolate bars, Consumer Reports used the maximum allowable dose level for lead and cadmium set by California “because we don’t have an FDA level,” Rogers says.
The FDA tells TODAY.com in an email statement that "the U.S. food supply is among the safest in the world. The FDA has not seen the testing data ... however ... environmental contaminants can be present in foods because they are in the environments where foods are grown, raised or processed. The presence of cadmium and lead in chocolate are well documented, as are the geographic differences in cadmium levels in soil where cocoa beans are grown."
"The FDA’s goal is to limit consumer exposure to environmental contaminants, with a focus on protecting the very young, through developing regulations, action levels, and advice to consumers. Generally speaking, the agency considers the health effects of the ‘whole food,’ which includes the potential harmful health effects of specific contaminants that may be present, as well as the food’s nutrients that help promote health and prevent disease throughout our lifespan. The FDA recommends that consumers eat a variety of healthy foods for nutrition and food safety."
"The FDA monitors and regulates levels of environmental contaminants, including lead and cadmium, in foods. To determine if the levels detected in food are a potential health concern, we consider the toxicity of the contaminant and exposure based on the level measured and consumption. We also may consider specific population groups (e.g., very young children). By law food manufacturers and processors have a responsibility to implement preventive controls to significantly minimize or prevent exposure to chemical hazards — including lead and cadmium. If the agency finds that the level of a contaminant causes the food to be unsafe, we take action, which may include working with the manufacturer to resolve the issue and taking steps to prevent the product from entering, or remaining in, the U.S. market. For example, the FDA has several chocolate products on our Import Alert for heavy metals in foods. (Please see: Import Alert 99-42)."
The FDA tests for environmental contaminants, including lead and cadmium, through the Total Diet Study; the FDA’s Toxic Elements in Food and Foodware, and Radionuclides in Food compliance program; and other surveys, which may be conducted annually or in response to reports of elevated contaminant levels in certain products or to focus on a specific food or food group. Testing may occur at the FDA laboratories or at state laboratories as part of our cooperative agreement with states. We recently selected dark chocolate as one of the matrices in our validation of Elemental Analysis Manual Method 4.7. This is the method used by the FDA to analyze for lead, cadmium, as well as other elements in all foods."
"The FDA monitors lead and cadmium levels in food to enforce the FDA regulations and inform agency guidance to industry and advice to consumers," the statement explained before listing three examples of testing for lead and cadmium in chocolate products:
- FDA Total Diet Study (TDS) FY2018-FY2020 Elements Report and Data (2022)
- Cadmium and lead in cocoa powder and chocolate products in the US Market (2018)
- Perspective on Cadmium and Lead in Cocoa and Chocolate (2020)
The statement concludes by sharing that FDA experts participate in CODEX, an "international standard-setting body" with the goal "to protect the health of consumers and promote fair trade practices by adopting scientifically based standards, guidelines, and codes of practice across all areas of food safety and quality," including a code of practice for preventing and reducing cadmium in cocoa beans.
In addition, the National Confectioners Association asserts that California's food safety standards are not a definitive standard.
“Food safety and product quality remain our highest priorities and we remain dedicated to being transparent and socially responsible,” Christopher Gindlesperger, the spokesperson for the association, notes.
A positive outcome of the investigation is that Consumer Reports also found five products that were considered safer, Rogers says. They include:
- Mast Organic Dark Chocolate 80% Cocoa
- Taza Chocolate Organic Deliciously Dark Chocolate 70% Cacao
- Ghirardelli Intense Dark Chocolate 86% Cacao
- Ghirardelli Intense Dark Chocolate Twilight Delight 72% Cacao
- Valrhona Abinao Dark Chocolate 85% Cacao
“Manufacturers can make dark chocolate with lower amounts of heavy metals,” Rogers says. “It may not be easy, but there are some things we believe manufacturers can do.”
Cadmium appears to come from soil contaminated with the heavy metal, which is then drawn up through the roots of the plant and ends up in the cocoa beans, so manufacturers could grow their chocolate plants in soil that tests low for cadmium, Rogers notes.
Lead, on the other hand, contaminates the cocoa beans though the environment when it is possibly windblown from the surrounding area as the beans dry out in the open, so one solution would be to move the processing facility somewhere else, he adds.
What to do if you love dark chocolate:
“Don’t panic because this is a manageable risk,” Rogers says. He offered the following tips:
Use the results of the investigation to shop wisely for dark chocolate.
Look for dark chocolate products with lower cacao percentages. Since the presence of heavy metals is a result of contaminated beans, try a bar that’s 70% cacao vs. 85%.
Don’t assume organic chocolate is safer because that's not what the Consumer Reports analysis found.
Alternate dark chocolate with milk chocolate and use it as a treat — not something that you eat daily.
There may be other sources of chocolate in your diet that you need to be aware of, such as hot chocolate or cocoa powder.
Heavy metal exposure is most dangerous for children and pregnant women, so they may want to skip dark chocolate.