A recent study by Consumer Reports found high levels of heavy metals in chocolate. A similar report on Consumer Lab was published at about the same time. As long-time lovers of chocolate, particularly dark chocolate, we were concerned to read these reports, and we decided to look into this further.
It’s easy to become fearful in a world where new information comes out all the time about the potential risks of this or that. And the media often takes advantage of a shocking turn (like SuperFood kale being “poisonous”) to get clicks. We don’t want to be a part of the fear spreading. Rather, we try to provide information on toxins or food products that we believe to be genuinely concerning, and to empower families to make the choices accessible for them to reduce their exposure to unhealthy or harmful foods and eat a healthier diet full of whole, nutrient-dense foods.
Heavy metals are all around us–in the soil, in coal ash, in old paint and old pipes, and in many other products and naturally occurring elements. They are a part of our world. However, prolonged exposure and ingestion of heavy metals can pose serious risks to human health. There are levels set by the FDA that set expectations and regulations for food producers, which includes regulating chocolate.
How much lead and cadmium are dangerous?
The Consumer Report study ranked chocolate products using the levels set by “California Proposition 65.” This proposition is intended to educate and warn consumers about potentially harmful substances in drinking water and has extended out into consumer products. It has some mixed reviews. A NY Times article compares the Prop 65 labels to “a noisy alarm that rings equally loudly about smaller amounts of low-risk substances and huge amounts of potentially harmful chemicals.” The article claims that because “labels don’t say how much of the chemical is present, or how much it would really take to make a person sick,” it can be hard to know whether the warning has genuine weight behind it or creates unnecessary concern.
Heavy Metals in Chocolate: Lead
For children, the FDA recommends a 3 mcg per day limit, and for adults a daily limit of 12.5 mcg. Based on this, the levels of lead in the chocolates tested do not raise huge alarm bells; however, to be safe, we will consider reducing the amount of chocolate we give to our children and being mindful of the brands that we buy. The Consumer Lab Report stated that all chocolate and cacao products tested showed less than 1 mcg of lead per suggested serving.
Heavy Metals in Chocolate: Cadmium
The United States has not set a federal limit for cadmium. California sets the daily limit at 4.1 micrograms. The EU established a limit of 0.6 mcg per gram of cocoa powder. In chocolates with over 50% cacao (dark chocolates), the EU allows up to 0.8 mcg/g. In milk chocolate, the limit is set low–at 0.1 mcg. Conservatively, the European Food Safety Authority estimates that someone weighing 150 lbs can tolerate 25 mcg daily of cadmium exposure (from all sources, not just food).
What Do Other Studies Say?
Researchers have also looked at the levels of heavy metals across chocolate types and location of origin. Dark chocolate with more cocoa had higher levels of cadmium and lead than the amount of heavy metals in milk chocolate. This makes sense as the bulk of milk chocolate comes from milk products rather than cacao. Also, products from Latin America tested higher in cadmium than from Africa. Because this study didn’t sample ALL chocolates from those two regions of the world, we can’t for certain say that all chocolate from Latin America will be higher in heavy metals than chocolate from African countries, but it may suggest a pattern.
Another study looking at heavy metals in chocolate showed that eating more than 42g of chocolate per day “may represent a health risk from cadmium for adults…” and eating more than 80g per day could pose a risk for lead exposure for adults. Because of the different levels noted in the samples from different growing regions, these researchers suggested that combining different sources of cocoa into a chocolate product could reduce the levels of metals. Another way to address that would be alternating the brand of chocolate that you buy.
As far as the issue goes moving forward, one study found a difference in the heavy metal accumulation between cacao plant varieties. So, there is an opportunity for cacao farmers to find and favor certain varieties of cacao plants that have been shown to accumulate less cadmium.
Basically, yes, there are varying amounts of heavy metals, mainly cadmium and lead, found in most chocolate. However, there are some brands and some sources that have tested lower.
Are Heavy Metals in Other Foods??
Unfortunately, yes. However, besides a few very small sample studies (like this one on kale), the studies have mostly been done in countries other than the United States, and most have not found particularly worrying numbers.
A study done in Poland “showed that the values of Cd [cadmium] and Pb [lead] in all types of tested fruit and vegetable samples: fresh as well as processed, frozen and dried, are very diverse.” In other words, some had high levels, some low, some in the middle, but most had a measurable amount of heavy metals. However, the cadmium levels in the Polish vegetables came in lower than many of the chocolate brands. Cadmium levels in the fruits and vegetables ranged from 0.05 micrograms per gram to 0.2 micrograms per gram.
For reference, in dark chocolate bars tested by Consumer Labs, cadmium levels ranged from 0.03 to 0.35 mcg/g. And in cacao/cocoa powders tested by Consumer Labs, cadmium levels ranged from 0.1 to 0.98 mcg/g.
One study tested a wide range of vegetables and fruits in Brazil. For the whole study, Cd concentrations ranged between 0.01 and 0.18 mcg/g, and Pb concentrations ranged between 0.02 and 2.50 mcg/g. That’s a pretty wide range, and the high range for lead is concerning. But the researchers concluded that there was not a significant risk of heavy metal toxicity to children or adults from eating the studied vegetables and fruits.
This study in India looked at a sample of vegetables and tested for a whole range of metals. In the conclusion, the researchers noted that levels of metals (and all nutrients) varied depending on “…the relative level of exposure of plants to the contaminated soil as well as the deposition of toxic elements in the polluted air by sedimentation.” So, unless you get testing on all the farms that you purchase vegetables from, you can’t know the real levels of metals in the vegetables you’re eating. This study concluded that the average person eating an average amount of the vegetables tested would stand no risk, with the exception of cadmium.
Our Current Suggestions
We take contamination of heavy metals seriously. These metals accumulate over time as they are stored in the fat and bones of our bodies. Kids are more susceptible to toxicity from heavy metals because they are smaller and still developing. But heavy metals are part of our environment, and although we wish that there was no risk of consuming them, they are likely present in very small amounts in many of our foods (from garlic to chocolate).
We are not recommending cutting out dark chocolate especially since we consider it to be a SuperHero Food, but we are reevaluating how often and what kinds of dark chocolate we recommend. After comparing levels of heavy metals found in other foods, we think that choosing dark chocolate and cacao that rank low in heavy metals and eating it in moderation is the best option.
We suggest that you minimize chocolate consumption for young children, and give chocolate in moderation to older children and yourself. Treat it as a special occasion food, rather than an everyday part of your diet. We plan to aim for 1-2 times a week maximum.
While we can’t guarantee these brands will have milk or dark chocolate without lead or cadmium, we can make suggestions for brands that have smaller amounts. We still value supporting organic and fair trade chocolate brands with minimal ingredients. Given this new data, we recommend these brands based on both their ingredients and their levels of heavy metals:
Hu chocolate bar came in at 0.08 mcg/g of cadmium and 0.03 mcg/g of lead, which is on the lower side of the products tested (Consumer Labs). High quality, minimal ingredients like organic cacao, organic coconut sugar, grass-fed milk, and organic nut butters.
After they were mentioned on the report, Hu responded to the Consumer Reports study. We appreciated that Hu took the time to give a thoughtful response with clear information explaining their processes.
Taking other steps to reduce the potential of being exposed to heavy metals is a good idea. For example, switching to non-toxic cookware can reduce your exposure to metals leached during preparation at home. We also suggest eating a variety of vegetables, fruits, and other foods, rather than eating a large amount of one food all the time.
What We’d Like to See in the Future
This is a nuanced topic, and as more information becomes available, we will adjust our recommendations. We would like to see more studies on ways that producers can reduce metal contamination in their cacao beans and resulting chocolate products and see cacao growers putting these methods into practice. We’ll also be continuing to reach out to dark chocolate manufacturers to better understand why some brands are lower in cadmium and lead than others.
We’d also like to see more monitoring and transparency from companies and/or farms. Heavy metals, particularly mercury, have been a concern in seafood for some time, and one brand, SafeCatch, has responded to this concern by building their brand on the premise of testing every salmon for mercury and only taking those that come in under the acceptable level. We think this would be great for a chocolate brand to take on too.