Photo: Voyagerix (Shutterstock)
We all likely still remember the (bad) news from this past December: A Consumer Reports investigation found 23 of the 28 dark chocolates from different brands they tested contained harmful levels of lead and cadmium. The results of the investigation made the rounds over mainstream media and is still very much in the minds of those who love the sweet treat—especially with Valentine’s Day barely behind us and Easter looming ahead.
It’s important to note that the Consumer Reports’ investigation was not peer-reviewed, nor did it contain large amounts of evidence. However, it does show eerily similar levels of heavy metals compared to a study published by the FDA in 2018 as well as other peer-reviewed studies dating back to 2005.
Luckily, there are things you can do to reduce your risk of getting these dangerous heavy metals in your system.
How much lead and cadmium is safe to consume?
Lead and cadmium are both considered heavy metals, and while they’re both found in nature, that doesn’t mean they’re good for you. “Some heavy metals really don’t have a function in your body. They don’t need to be there, and some of them accumulate,” Dr. Katarzyna Kordas, associate professor of environmental health at the University at Buffalo School, told WebMD’s Nourish.
But because most of us just can’t (well, don’t want to) quit dark chocolate cold turkey, here are some numbers for you: The U.S. Agency for Toxic Substances and Disease Registry recommends a “minimal risk level” of about six micrograms of cadmium per day for a 130-pound person, and per European safety standards, 21 micrograms a day for the same person, according to the New York Times. To put that into context, a single ounce serving of dark chocolate has about 7.6 micrograms of cadmium, according to the 2018 FDA report.
The scary thing is that the average American already eats about five micrograms of cadmium per day in our regular daily diet, according to a 2019 study by Dr. Melissa Melough, an assistant professor of nutrition at the University of Delaware. You throw a couple daily ounces of dark chocolate into that average, and you could be above those safe levels.
What are the risks of lead and cadmium in our system?
Cadmium stays in your system for decades, and long-term exposure is known to cause cancer, kidney damage, and weaken your bones. These effects are magnified for fetuses and during early life stages, according to multiple peer-reviewed studies. Lead affects your respiratory and gastrointestinal tracts, nervous system, and kidneys.
Because they accumulate, it’s important to know where you’re eating them from and how much you’re getting into your system. It’s true that it’s almost impossible to completely cut out these heavy metals from our lives, so knowing which foods have high levels (like this FDA report showing dark chocolate had the third-highest concentrations of both cadmium and lead from 300 other foods) can benefit us from reaching dangerous levels by limiting our amounts where we can.
How does lead and cadmium get in my chocolate?
The researchers from Consumer Reports found that lead got into the cacao after harvest, mostly on the outer shell of the cocoa bean. As far as cadmium, the cacao plants take up the metal from the soil, accumulating in the cacao beans as the tree matures.
Certain soils in different geographical regions have shown to have different levels of these metals. The 2018 FDA study shows higher concentrations of cadmium were found in chocolate originating from Latin America when compared to Africa. It’s important to note that a lot of variation exists in chocolate production in Latin America, with elevated numbers coming from hotspots, as this report from Clima-LoCa mentions. So not all Latin American chocolate will necessarily have higher levels than chocolate from African, but it’s still worth noting.
The Consumer Reports investigation and the 2018 FDA study both mention that milk chocolate has lower levels of heavy metals because it has lower levels of cacao. While there is no official cutoff on where dark chocolate stops and milk chocolate begins, dark chocolates are generally considered to start at 65% cacao, as Dr. Michael J. DiBartolomeis, a toxicologist who has researched heavy metals in chocolate, told Consumer Reports.
How can I avoid lead and cadmium in my chocolate?
The good news is that you don’t necessarily have to give up dark chocolate completely. There are ways to mitigate the risks of accumulating dangerous levels of heavy metals in your body from dark chocolate, even for pregnant people and children. Here’s how.
Choose dark chocolates with low levels of heavy metals
Out of the 28 dark chocolates Consumer Reports tested, five chocolates were found safe to eat. Enjoy those and avoid the other ones. (And if you were wondering, organic chocolates had no difference in heavy metal levels, per the report.) Another great resource for safe chocolates is As You Sow’s chocolate tracker of cadmium and lead, which measures the levels in products from several chocolate brands.
Treat chocolate as a treat
Remember that it is the frequent consumption of these heavy metals that can lead to dangerous levels accumulating in your body. So if you can’t see yourself living without dark chocolate, eat it sparingly. Melough recommends you eat no more than an ounce per day to avoid not only heavy metals, but also saturated fat. A 2022 study showed all you need to reap the health benefits of dark chocolate is to eat one-third of an ounce per day.
Eat dark chocolate with lower cacao percentages
As mentioned, Consumer Reports and the FDA’s tests suggest that cadmium levels tend to be lower on chocolates with lower percentages of cacao. So if you have a choice between 65% and 80%, go with the 65%. Unfortunately, lead levels don’t seem to make a difference on the cacao percentage.
Go for the milk chocolate
Anything lower than 65% is generally considered milk chocolate, so milk chocolates will have lower heavy metals in general. Just keep in mind that you will be eating a lot more added sugars and might not get the same health benefits as the dark chocolate.
Children and pregnant people should eat less
Melough told the New York Times that those who are pregnant or breastfeeding should consider eating dark chocolate only once or twice a week because of the greater risk of harm from heavy metals during early stages of human development. Most kids prefer milk chocolate anyway, so at least that shouldn’t be much of an issue.