A new study found dozens of popular chocolates made in the U.S. and Europe contain more heavy metals than the limit set by a California law, according to a report published Wednesday in the peer-reviewed journal Frontiers in Nature.

The 1986 California law, Proposition 65, requires businesses to inform state residents about products containing toxic substances – including heavy metals – that are known to cause cancer, birth defects and reproductive harm.

While the elevated levels of metals in chocolate are concerning, consumers needn’t cut this delicious staple from their diet, said study co-author Leigh Frame, director of integrative medicine and associate professor at George Washington University.

“I’m a chocolate lover myself so you’ll be glad to hear that chocolate isn’t going to kill us,” she said. But like all things, moderation is key.

How heavy metals get into your chocolate

Lead and cadmium are elements found in nature that can affect every tissue in the body by inserting themselves into cellular processes involved in major bodily functions.

Children are especially vulnerable if they ingest heavy metals, particularly in terms of their neurological development. Exposure can damage the brain and nervous system, slow growth and development and trigger learning and behavioral problems.

In Wednesday’s study, researchers from George Washington University studied samples of more than 70 treats over eight years, from 2014 to 2022. They found that 43% of the chocolate products studied exceeded the maximum allowable dose of lead and 35% exceeded the amount for cadmium. Frame declined to name the brands of chocolate used in the research, saying all chocolate is likely affected, regardless of brand.

Heavy metals make their way into chocolate through the cacao bean, said Danielle Fugere, president and chief counsel at As You Sow, a nonprofit that worked with the chocolate industry to produce an investigative report on heavy metals in chocolate in 2022.

Lead in America’s water pipes Lead can alter personalities and pose lifelong risks

The report found cacao trees absorb microscopic amounts of cadmium from the soil through the roots that build up in the cacao beans.

“It’s a naturally occurring metal,” said Ana M. Rule, assistant professor and director of the Exposure Assessment Laboratories at Johns Hopkins Bloomberg School of Public Health, who was not affiliated with either study. “But just because they’re naturally occurring, doesn’t mean they’re safe.”

Lead contamination can also occur at various stages of chocolate production – during the harvesting, drying and fermenting of cacao beans.

The beans can accumulate lead from the environment on their sticky surfaces as they’re drying on contaminated ground or the side of the road in a place with heavy metals from car pollution. Lead can also be introduced during the manufacturing process, Fugere said.

“We added (heavy metals) to products and now they’re in the soil and pollution,” said Frame, from George Washington University. “As they start to accumulate in the environment, they become a problem.”

What’s the deal with dark and organic chocolate

Heavy metals are more of a glaring problem in some chocolate products than others. For example, samples of dark chocolate contained higher levels of lead and cadmium, according to the GW study.

Experts say dark chocolate uses more concentrated cacao than milk chocolate, which explains why it could have a higher concentration of heavy metals.

The study authors were surprised to find organic products contained higher levels of cadmium and lead than more processed chocolate. Frame suggested this could be because organic chocolate is less processed, which means the concentration of chocolate and heavy metals in it is less diluted.

Lead paint is just the beginning Poisoning danger lurks in your pantry and toys

Another explanation for the difference, Fugere said, is that organic chocolate producers tend to operate in a single area, and single-origin chocolate is likelier to have higher levels of heavy metals than chocolate products in which cacao beans have been harvested from various places around the world.

Single-origin producers who harvest from an environment high in cadmium or lead don’t include beans from other regions in their chocolate to dilute the concentration of heavy metals, she said.

What the chocolate industry can do

Using a mix of cacao beans from different areas of the world is one effective way chocolate producers can reduce the levels of heavy metals in their products, experts said.

As You Sow determined in its 2022 report exporters could stop purchasing beans from regions where cacao is high in heavy metals; farmers could also stop planting new orchards in those regions.

Experts also recommend that cacao farmers increase the soil pH and chocolate makers establish clean practices to prevent lead contamination, which Fugere said includes replacing the equipment manufacturers use to prevent lead from being introduced in the processing stage.

It’s also important at the end stage, to continue testing chocolate products to gauge areas of improvement, Rule, from Johns Hopkins, said.

“Every time we look for metals, we’re finding them,” she said. “It’s good to keep monitoring these consumer products to be able to identify sources and inform (people).”

What you can do as a consumer

Of course, chocolate isn’t all bad. And research has shown it has some health benefits.

Chocolate is rich in flavonoids, which contain anti-inflammatory, antioxidant and anti-carcinogenic properties. Flavonoids are also associated with heart and brain benefits, reducing high blood pressure and improving cognitive function.

If you want the health benefits from chocolate but hope to reduce your heavy metal exposure, you should limit chocolate consumption to 1 or 2 ounces per day, experts said. That’s the equivalent of about nine Hershey’s Kisses. Frame says she’s been able to curb her chocolate habit by limiting her intake to every other day.

“I’m a big lover of chocolate and the way that I found to moderate intake is to focus on it as a treat,” she said.

Health experts also urge consumers to research other foods that contain high levels of heavy metals to avoid pairing them in a meal with chocolate.

“These days, what we consume is so processed that we lose track of all the places where it can get contaminated,” Rule said. “It’s important to be vigilant.”

Adrianna Rodriguez can be reached at [email protected].

This article originally appeared on USA TODAY: Lead, cadmium found in dozens of your favorite chocolate products

A new study found dozens of popular chocolates made in the U.S. and Europe contain more heavy metals than the limit set by a California law, according to a report published Wednesday in the peer-reviewed journal Frontiers in Nature.

The 1986 California law, Proposition 65, requires businesses to inform state residents about products containing toxic substances – including heavy metals – that are known to cause cancer, birth defects and reproductive harm.

While the elevated levels of metals in chocolate are concerning, consumers needn’t cut this delicious staple from their diet, said study co-author Leigh Frame, director of integrative medicine and associate professor at George Washington University.

“I’m a chocolate lover myself so you’ll be glad to hear that chocolate isn’t going to kill us,” she said. But like all things, moderation is key.

How heavy metals get into your chocolate

Lead and cadmium are elements found in nature that can affect every tissue in the body by inserting themselves into cellular processes involved in major bodily functions.

Children are especially vulnerable if they ingest heavy metals, particularly in terms of their neurological development. Exposure can damage the brain and nervous system, slow growth and development and trigger learning and behavioral problems.

In Wednesday’s study, researchers from George Washington University studied samples of more than 70 treats over eight years, from 2014 to 2022. They found that 43% of the chocolate products studied exceeded the maximum allowable dose of lead and 35% exceeded the amount for cadmium. Frame declined to name the brands of chocolate used in the research, saying all chocolate is likely affected, regardless of brand.

Heavy metals make their way into chocolate through the cacao bean, said Danielle Fugere, president and chief counsel at As You Sow, a nonprofit that worked with the chocolate industry to produce an investigative report on heavy metals in chocolate in 2022.

Lead in America’s water pipes Lead can alter personalities and pose lifelong risks

The report found cacao trees absorb microscopic amounts of cadmium from the soil through the roots that build up in the cacao beans.

“It’s a naturally occurring metal,” said Ana M. Rule, assistant professor and director of the Exposure Assessment Laboratories at Johns Hopkins Bloomberg School of Public Health, who was not affiliated with either study. “But just because they’re naturally occurring, doesn’t mean they’re safe.”

Lead contamination can also occur at various stages of chocolate production – during the harvesting, drying and fermenting of cacao beans.

The beans can accumulate lead from the environment on their sticky surfaces as they’re drying on contaminated ground or the side of the road in a place with heavy metals from car pollution. Lead can also be introduced during the manufacturing process, Fugere said.

“We added (heavy metals) to products and now they’re in the soil and pollution,” said Frame, from George Washington University. “As they start to accumulate in the environment, they become a problem.”

What’s the deal with dark and organic chocolate

Heavy metals are more of a glaring problem in some chocolate products than others. For example, samples of dark chocolate contained higher levels of lead and cadmium, according to the GW study.

Experts say dark chocolate uses more concentrated cacao than milk chocolate, which explains why it could have a higher concentration of heavy metals.

The study authors were surprised to find organic products contained higher levels of cadmium and lead than more processed chocolate. Frame suggested this could be because organic chocolate is less processed, which means the concentration of chocolate and heavy metals in it is less diluted.

Lead paint is just the beginning Poisoning danger lurks in your pantry and toys

Another explanation for the difference, Fugere said, is that organic chocolate producers tend to operate in a single area, and single-origin chocolate is likelier to have higher levels of heavy metals than chocolate products in which cacao beans have been harvested from various places around the world.

Single-origin producers who harvest from an environment high in cadmium or lead don’t include beans from other regions in their chocolate to dilute the concentration of heavy metals, she said.

What the chocolate industry can do

Using a mix of cacao beans from different areas of the world is one effective way chocolate producers can reduce the levels of heavy metals in their products, experts said.

As You Sow determined in its 2022 report exporters could stop purchasing beans from regions where cacao is high in heavy metals; farmers could also stop planting new orchards in those regions.

Experts also recommend that cacao farmers increase the soil pH and chocolate makers establish clean practices to prevent lead contamination, which Fugere said includes replacing the equipment manufacturers use to prevent lead from being introduced in the processing stage.

It’s also important at the end stage, to continue testing chocolate products to gauge areas of improvement, Rule, from Johns Hopkins, said.

“Every time we look for metals, we’re finding them,” she said. “It’s good to keep monitoring these consumer products to be able to identify sources and inform (people).”

What you can do as a consumer

Of course, chocolate isn’t all bad. And research has shown it has some health benefits.

Chocolate is rich in flavonoids, which contain anti-inflammatory, antioxidant and anti-carcinogenic properties. Flavonoids are also associated with heart and brain benefits, reducing high blood pressure and improving cognitive function.

If you want the health benefits from chocolate but hope to reduce your heavy metal exposure, you should limit chocolate consumption to 1 or 2 ounces per day, experts said. That’s the equivalent of about nine Hershey’s Kisses. Frame says she’s been able to curb her chocolate habit by limiting her intake to every other day.

“I’m a big lover of chocolate and the way that I found to moderate intake is to focus on it as a treat,” she said.

Health experts also urge consumers to research other foods that contain high levels of heavy metals to avoid pairing them in a meal with chocolate.

“These days, what we consume is so processed that we lose track of all the places where it can get contaminated,” Rule said. “It’s important to be vigilant.”

Adrianna Rodriguez can be reached at [email protected].

This article originally appeared on USA TODAY: Lead, cadmium found in dozens of your favorite chocolate products