Dr Martin Juneau, M.D., FRCP

Cardiologue, directeur de l'Observatoire de la prévention de l'Institut de Cardiologie de Montréal. Professeur titulaire de clinique, Faculté de médecine de l'Université de Montréal. / Cardiologist and Director of Prevention Watch, Montreal Heart Institute. Clinical Professor, Faculty of Medicine, University of Montreal.

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7 January 2026
Should we be worried about the presence of cadmium in dark chocolate?

Overview

  • Cadmium is a toxic heavy metal, particularly harmful to the kidneys, that can accumulate naturally in the cacao beans used to make chocolate.
  • This accumulation in the beans depends directly on the amount of cadmium present in the soil and therefore varies considerably depending on the geographical origin of the cacao, with the lowest levels found in cacao from the African continent and the highest in cacao from Latin America.
  • Despite these differences, analysis of a wide range of chocolate products indicates that almost all products made from either source of cacao contain amounts of cadmium below toxicity thresholds and can therefore be consumed without any health risks.

As previously mentioned, cacao and its derivatives, particularly dark chocolate, are exceptional sources of polyphenols, a class of antioxidant molecules involved in the prevention of several major chronic diseases associated with oxidative stress, including cardiovascular disease, cancer, type 2 diabetes, and neurodegenerative diseases.

The cardiovascular system appears to be the primary beneficiary of the positive effects of cacao polyphenols, with a significant reduction in blood pressure observed in several epidemiological and clinical studies. It has been suggested that this antihypertensive effect is linked, at least in part, to an increase in the formation of the vasodilator nitric oxide (NO) by certain polyphenols (epicatechin) present in large quantities in cacao.

Cadmium accumulation

Another, less positive, characteristic of chocolate is that it frequently contains varying levels of certain heavy metals, particularly cadmium. The presence of this metal is problematic at first glance, given its high toxicity, primarily to the kidneys, and its statistical association with an increased risk of lung, endometrial, bladder, and breast cancers.

This cadmium accumulation is due to the cacao tree’s (Theobroma cacao) ability to extract this metal from the soil using its roots and transport it throughout the tree via its vascular system. It is first transported to the leaves (via the xylem) and then, via the phloem, to the pods, which are the fruits of the cacao tree that contain the beans used to make chocolate (Figure 1). In other words, the presence of cadmium in chocolate is a natural phenomenon, directly linked to the cadmium content of the soil in cacao plantations.

Figure 1. Schematic representation of the processes responsible for the presence of cadmium in chocolate. A. Most of the cadmium in the Earth’s crust comes from natural sources, such as sedimentary rocks like limestone and black shale, which release the metal when they decompose. Industrial pollution and phosphate fertilizers, which are produced from sedimentary rocks, can also contribute to the presence of cadmium in the soils of cacao plantations. B. Usable forms of cadmium are absorbed by the root cells of the cacao tree and transported by the xylem to the leaves (light blue line). C.The cadmium stored in the leaves is subsequently remobilized by the phloem and transported to the pods (red line) where it is incorporated into the beans inside the pods. D. The majority of this cadmium is subsequently found in the finished product following the various processing stages of the harvested beans (fermentation, drying, grinding). Adapted from García Porras et al. (2025).

International variations

This influence of the soil means that the cadmium levels that can accumulate in cacao beans vary enormously depending on where the plantations are located. The cacao tree requires a tropical climate to grow, so all the cacao produced worldwide comes from regions between 20° latitude on either side of the equator (Figure 2). The geology of these different regions is obviously quite varied; in West Africa, for example, cacao-producing countries like Côte d’Ivoire and Ghana are located in an area where the rocks are very old (over 2 billion years old) and whose very long erosion has considerably reduced their cadmium content. Conversely, the formation of the Andes in Latin America is relatively recent (20-30 million years ago) and these younger soils are therefore necessarily richer in cadmium, while in Asia (e.g., in Indonesia), where the soils were formed about 100 million years ago, the cadmium content levels are intermediate.

Figure 2. Distribution of global cacao production. The main cacao-producing areas are all located around the equator, between 20° north and 20° south latitude, in what is known as the “cacao belt.” Note that only the largest producing countries (> 10,000 tonnes per year) are shown in the figure. Overall, Africa (3.1 million tonnes, 68% of total production) is by far the main source of cacao, far ahead of Latin America (0.93 million tonnes, 17%) and Asia (0.69 million tonnes, 12%). From Our World in Data.

Cadmium levels in cacao beans from various regions of the world reflect these differences in soil geological age: cacao from Africa contains very little cadmium, cacao from Asia about four times more, while cacao grown in Latin America has the highest average levels (Figure 3). In some regions (Santander in Colombia, for example), average cadmium levels in cacao are around 3 mg/kg and can even reach 8 mg/kg in some plantations, a direct consequence of the high cadmium content of the soils in this region.

Figure 3. Cadmium content of cacao beans according to their region of origin. The coloured boxes represent the distribution of mean values ​​determined by different studies, and the white line inside is the average of all these means. From Meter et al. (2019). The dotted line indicates the maximum cadmium level required to remain below the limits imposed by the European Union (see next section).

Maximum permissible cadmium levels

Although they represent only 6% of the world’s population, Europeans alone consume 50% of all cacao produced annually and were therefore among the first to impose limits to reduce the health risks associated with cadmium ingestion through chocolate consumption. These limits range from 0.1 to 0.8 mg/kg, depending on the cacao content of the finished product (Table 1).

ProductsMaximum levels (mg/kg)
Milk chocolate with < 30 % cacao0.1
Milk chocolate with > 30% cacao
Dark chocolate with < 50% cacao		0.3
Dark chocolate with ≥ 50% cacao0.8

Table 1. Maximum cadmium levels permitted by the European Union for various chocolate products. From Euro-Lex. Note that in California, although Proposition 65 set the cadmium limit at 4.1 µg per day, which is equivalent to approximately 0.136 mg/kg for a 30 g serving, a 2018 consent judgment allows limits quite similar to those of the EU: 0.32 mg/kg for products containing < 65% cacao, 0.45 mg/kg for those between 65-95%, and 0.8 mg/kg for a content > 95%.

These maximum permitted levels, which came into effect in January 2019, apply to chocolate products and not to the raw material, i.e., cacao beans. However, the following equation allows us to estimate the maximum level of cadmium present in the initial mass of cacao used that will allow the chocolate product to remain below the threshold set by the EU:

LCdmax = LCdmax EU ÷ P% cacao

where :

LCdmax = maximum cadmium level in cacao beans (mg/kg)

LCdmax EU = maximum cadmium level allowed by the EU in the final product (mg/kg)

P% cacao = % of cacao in the final product 

If we take, for example, the case of dark chocolate containing 70% cacao mass, for which the European regulation sets a maximum cadmium limit of 0.8 mg/kg in the finished product, the maximum cadmium content in the cacao beans will be:

LCdmax = 0.8 ÷ 0.7 = 1.1 mg/kg

According to this calculation, the vast majority of cacao produced worldwide, whether from Africa, Asia, or Latin America, complies with the maximum cadmium limits and is therefore perfectly safe (Figure 3). However, cacao beans from some Latin American plantations exceed these limits, and it is therefore possible that some chocolates made from these sources may contain cadmium levels exceeding acceptable limits.

Cadmium in chocolate bars

This is essentially what the analysis of chocolate products intended for consumption demonstrates: the amount of cadmium they contain is, in the vast majority of cases, below the permitted standards, regardless of the origin of the cacao used in their production (Figure 4).

Figure 4. Cadmium concentration in chocolate products according to cacao origin. The values ​​represent the averages for products made from cacao from Africa (n=42), Asia (n=10), Latin America (n=37), or a mixture from several countries (n=61). Note that the overall average cadmium content of all products analyzed in the study is 0.132 mg/kg, with values ​​ranging from a minimum of 0.0003 mg/kg (West Africa) to a maximum of 0.843 mg/kg (Latin America). Adapted from Godebo et al. (2024).

The cadmium concentration is generally directly correlated with the percentage of cacao present in the chocolate product and remains below the permitted limit for the vast majority (154/155) of the products analyzed in the study (Figure 5), with the notable exception of one product containing 100% cacao from Colombia. It is therefore clear that the vast majority of chocolate products available for consumption contain non-toxic amounts of cadmium and are perfectly safe. Only certain products, from plantations located in areas with high levels of cadmium, may exceed these limits.

Figure 5. Amount of cadmium present in different products according to their cacao content. Note that of the 155 products tested, only one (from Colombia) exceeds the maximum amount of cadmium set by the EU according to cacao content (indicated in red). Adapted from Godebo et al. (2024).

Overall, these results are very reassuring and certainly do not justify the alarmist conclusions of two analyses conducted in 2022 and 2023 by the magazine Consumer Reports. These analyses revealed that several chocolate products should be considered potentially dangerous because they contain cadmium levels exceeding the California limit of 0.0041 mg (or 4.1 µg) of cadmium per day (a comprehensive list of products containing cadmium levels below or above this 4.1 µg limit can be found here). This conclusion was, however, somewhat premature, given that this very conservative limit (arbitrarily set at 1/1000 of the smallest dose with no toxicity) is much lower than that used by the WHO, the US FDA, the European Union, and even… California! (see the legend for Table 1). When these limits are used as the criterion, the data obtained clearly show that the vast majority of products are perfectly safe, regardless of their cacao content (Figure 5). According to the calculations made by the study authors, only children weighing less than 24 kg (approximately 6 years old for most people) who consumed chocolate products with the highest cadmium levels on a daily basis could theoretically be at risk of exposure to toxic amounts of the heavy metal.

Dietary cadmium

Another factor that puts the presence of cadmium in chocolate into perspective is that several plants other than the cacao tree accumulate cadmium and thus contribute to the population’s exposure to this metal. This is particularly true for smokers, who have blood cadmium levels twice as high as non-smokers (the tobacco plant is an excellent cadmium accumulator). In non-smokers, 90% of cadmium comes from food, especially grains and vegetables (particularly leafy greens), which alone account for about a third of cadmium exposure, almost 10 times more than that from chocolate (Figure 6). This is because, even though they contain cadmium concentrations at least three times lower than those of cacao (0.038 vs. 0.130 mg/kg), these foods are consumed in much larger quantities and therefore contribute far more to daily cadmium intake than chocolate (Figure 6). In other words, you probably ingest more cadmium from the staple foods you eat every day, such as cereals, leafy green vegetables, potatoes, and legumes, than from your daily consumption of dark chocolate.

Figure 6. Contribution of different foods to cadmium intake in European adults. The values ​​represent the percentages of cadmium in total food intake, at around 0.002 mg/kg of body weight per week, which is much lower than the maximum value set by the WHO (0.007 mg/kg per week). Note that chocolate is a relatively minor source of cadmium (4%), containing far less than some commonly consumed foods such as cereals, vegetables, tubers, and meat. This is consistent with a review of studies conducted by the WHO, which shows that the contribution of cacao-containing products to dietary cadmium exposure is minor (0.1 to 9.4%), even in countries where consumption of these products is relatively high. From the European Food Safety Authority (EFSA) (2012).
 

In short, the cadmium in dark chocolate poses no health risk to the vast majority of people who consume it regularly in moderate amounts (1–2 portions of 30 g per day), especially if the cacao used in its production comes from the African continent.

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