Heavy Metals Found in Chocolate: Is It Safe to Eat

If you're a chocolate lover, you're probably not happy to know that dark chocolate can be tainted with heavy metals. One study found that many brands of dark chocolate contained trace amounts of lead and cadmium.

But does this mean you should stop eating chocolate altogether? Aside from being a satisfying treat, dark chocolate is also a great source of antioxidants, which are known for their health benefits.

Heavy metals can be found in many of the foods we eat, but usually in very small amounts. So it's hard to avoid them altogether. The question is, are levels of heavy metals in dark chocolate too high?

Dark chocolate and heavy metals: What's the connection?

Several studies have shown that some dark chocolate products contain trace amounts of heavy metals. A 2024 study found that almost 4 in 10 dark chocolate products tested contained potentially unsafe levels of lead or cadmium.

Heavy metals can get into chocolate in a few ways. Metals exist naturally in soil and they can accumulate in the soil and air from pollution. Cocoa beans can absorb heavy metals from the soil. And the beans may also be contaminated by heavy metals during their processing. Beans are left out to dry in the sun before processing. Lead from exhaust fumes and dust can settle onto the beans if they aren't covered.

Dark chocolate has a high concentration of cocoa. That's what gives it the dark, rich flavor. But the cocoa content is also why dark chocolate is more likely to have heavy metals than milk chocolate.

Is it safe to eat dark chocolate?

It's probably safe for most adults to eat dark chocolate in moderation.

The study mentioned earlier tested one serving (1 oz) of 72 dark chocolate products between 2014 and 2022. The researchers used standards from Proposition 65 (Prop 65), a California law that has even lower allowable limits of metals than regulations by the FDA.

The study found that about 40% of dark chocolate products had levels of lead or cadmium above the limit proposed by Prop 65. That's not great news on its face. But there are a few reasons not to worry.

First, metal levels in chocolate seem to be going down. Fewer bars tested in 2022 exceeded Prop 65 limits compared to 2014.

Second, the metal levels in the chocolate bars were still far below FDA recommended limits. Almost all dark chocolate tested had lead levels that were about four times lower than the FDA recommended limits for children under 7 years old. They were 12 times lower than the FDA recommended limits for expectant mothers.

"The risk of adverse health effects of exposure to cadmium or lead, and other metals from consumption of an ounce of chocolate daily in the U.S. is negligible for adults," said Tewodros Godebo, assistant professor of environmental health sciences at Tulane University School of Public Health and Tropical Medicine.

Since there are still some bars on the market that may have higher levels, you may want to limit your dark chocolate to 1 oz to 2 oz a day. An ounce may not sound like a lot, but most adults eat less than 1 oz a day of chocolate averaged over a year.

Or you can buy brands that are known to have low levels of metals (more on that later).

Is dark chocolate safe for children and in pregnancy?

There's no amount of heavy metal exposure that's considered safe for children or a developing fetus.

"Heavy metals like lead and cadmium in chocolate are especially concerning for young children and pregnant women," said Luz Claudio, PhD, professor of environmental medicine and climate science at Icahn School of Medicine at Mount Sinai.

That's because their brains are still developing and are more sensitive to toxins. "Even small amounts can potentially affect a child's brain development," Claudio said. She added that it's not yet clear if the levels in chocolate could cause a problem.

So it may be a good idea to limit dark chocolate for young children. And if you're pregnant and concerned about exposure to your developing fetus, consider limiting your dark chocolate to less than 1 oz a day or avoiding it altogether.

Which dark chocolate is safest to eat?

Consumer Reports recently tested 28 dark chocolate bars for lead and cadmium. They found a few chocolate bars with levels of heavy metals below California's maximum allowable dose level. These include:

• Ghirardelli Intense Dark Chocolate 86% Cacao

• Ghirardelli Intense Dark Chocolate Twilight Delight 72% Cacao

• Taza Chocolate Organic Deliciously Dark Chocolate 70% Cacao

• Valrhona Abinao Dark Chocolate 85% Cacao

You can also look for "single origin" dark chocolates made from cocoa beans from countries in Asia and West Africa. Products from these regions have less toxic metal content than chocolates from South America.

What are the risks of consuming heavy metals?

Everyone has some heavy metals in their bodies. Metals come from food and the environment. Usually the amounts that people consume are tiny and don't rise to the level that they can cause health issues.

But sometimes, people can be exposed to higher levels of heavy metals, most often through workplace exposures. Or sometimes through tainted water or food. Very high levels in the body can cause heavy metal poisoning. Heavy metal poisoning can cause:

• Damage to your kidneys and nervous system

• Cardiovascular disease and diabetes

• Cancer

• Cognitive issues

Heavy metal poisoning is very rare in adults.

What are the benefits of eating dark chocolate?

Aside from enjoying the taste of dark chocolate, some people eat it for its potential health benefits. Dark chocolate contains flavanols, a type of antioxidant. It also has minerals like magnesium, and other components that have been linked to certain health benefits. These include:

• Lower cholesterol and blood pressure

• Lower risk of diabetes

• Improved gut microbiome

What other foods contain heavy metals?

Heavy metals can exist in many foods. But there are some that are known to have higher levels. That's why it's important to be mindful of your entire diet, since the amounts of heavy metals can add up. In particular, these foods are known to have higher amounts of heavy metals:

• White and brown rice have higher concentrations of arsenic.

• Some types of fish contain high amounts of mercury.

• Ground cinnamon contains higher levels of lead.

• Spinach has higher amounts of cadmium.

To reduce your heavy metal consumption, consider making some adjustments to your diet. For instance, try lower mercury varieties of seafood (like shrimp and salmon) instead of fish with higher mercury levels, like swordfish and bigeye tuna.

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