Dangerous heavy metals have been found in dark chocolate from brands including Hershey's. Here's how to safely enjoy your favorite treats.

• Consumer Reports tested 48 popular chocolate products for heavy metals.
• A third of products, mostly dark chocolate, contained concerning levels of lead and cadmium.

If you eat a lot of dark chocolate, you may want to reconsider which brands you buy, a nutrition expert says, after a new report found potentially harmful levels of heavy metals in some popular products.

Consumer Reports, a nonprofit consumer organization, tested 48 chocolate products for heavy metals from seven categories: cocoa powder, chocolate chips, milk-chocolate bars, dark-chocolate bars, brownie mixes, chocolate-cake mixes, and hot-chocolate powder. In a report released last year, the organization found heavy metals in 23 out of 28 dark-chocolate bars, and it added a few more dark-chocolate bars to its latest test.

In the report released on October 25, Consumer Reports found that all 48 products it tested contained detectable amounts of lead and cadmium, heavy metals linked to an increased risk of conditions such as cancer and developmental issues in children.

And 16 of those 48 products, from brands such as Hershey's, Hu, Perugina, Walmart, and Nestlé, were found to contain at least one heavy metal at higher levels than Consumer Reports considered safe.

A 3rd of the chocolate products contained concerning levels of heavy metals

As there are no federal limits for the amount of lead and cadmium that most food can safely contain, Consumer Reports used California's maximum allowable dose levels for these substances, which it said were "the most protective available," at 0.5 micrograms of lead and 4.1 micrograms of cadmium a day.

A third of the products tested contained more cadmium and lead than Consumer Reports' safe level, including Perugina's 85% Premium Dark Chocolate, which contained 539% of the level of concern for lead, and Evolved's Signature Dark 72% Cacao Chocolate Bar, which contained 149% of the level of concern for cadmium.

Most of the milk-chocolate bars, chocolate chips, and cake and brownie mixes didn't contain concerning levels of lead and cadmium, but most of the dark-chocolate bars, hot-chocolate powders, and cocoa powders contained levels above or closer to the level of concern.

Lead and cadmium exposure can be dangerous, but you don't need to throw out your chocolate

Lead exposure can harm fetuses, cause physical- and mental-development issues in children, and cause reproductive issues, pain, and difficulties with memory or concentration in adults, according to the Mayo Clinic. Prolonged cadmium exposure can lead to kidney disease, fragile bones, and cancer, according to the Centers for Disease Control and Prevention.

But a spokesperson for the US Food and Drug Administration told "Today" that despite the "considerable media attention" on the presence of cadmium and lead in chocolate, "experts from around the world have found that chocolate is a minor source of exposure to these contaminants internationally."

So, Consumer Reports' findings don't mean you should stop eating chocolate products, as Melissa Melough, a nutritional epidemiologist who's an assistant professor of nutrition at the University of Delaware, told Insider.

"If you're eating a reasonable amount of dark chocolate or limiting yourself to the portions that are recommended on the packaging each time that you do choose to eat it, then I wouldn't be terribly concerned about your heavy-metal intake," she said.

But Melough said young children and people who are pregnant or breastfeeding should try to limit their exposure to heavy metals through chocolate as much as possible because of their potential impact on fetal and childhood development.

If you're worried, choose specific products and consider switching to milk chocolate

If you eat a lot of dark chocolate, you're pregnant or breastfeeding, or you're just worried about eating heavy metals, Melough recommended opting for the products that Consumer Reports found to contain lower amounts of heavy metals to minimize your ingestion of them.

These include:

• Sam's Choice (Walmart) Dark Chocolate 85% Cocoa

• Lindt Classic Recipe Milk Chocolate Bar

• Ghirardelli Premium Baking Bittersweet Chocolate Chips 60% Cacao

• Navitas Organics Organic Cacao Powder

Melough said another way to reduce your heavy-metal intake from chocolate was switching to milk chocolate because of its lower cocoa content. Chocolate is contaminated by heavy metals during the growth and processing of cocoa plants, so products with lower cocoa content tend to contain lower amounts of heavy metals, as Consumer Report's results reflected.

A spokesperson for Nestlé, which owns Perugina, told Insider its products complied with "all applicable regulatory requirements." Hu said in a statement that it complied with "all applicable standards" by "a very large margin."

Rick Gusmano, the cofounder of Evolved Chocolate, told Insider the company made sure its products contained levels of heavy metals that were well below the levels suggested in a settlement by As You Sow, a nonprofit organization that tests for heavy metals and pushes for corporate responsibility around environmental health and human rights.

Walmart and Hershey's did not respond to requests for comment.