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  • Adriano dos Santos

The Dark Chocolate Controversy: Unveiling the Metal Content and Safety Standards

Updated: Jun 1, 2023

Indulging in a delectable bar of dark chocolate is a delight for many, but recent findings from an investigative report have sparked concerns about the levels of metals present in popular chocolate brands. This blog post aims to shed light on the dark chocolate controversy, addressing the presence of metals such as lead and cadmium, the potential risks associated with their consumption, and the existing safety standards.

Understanding the Dose and Natural Elements

Before jumping to conclusions, it is essential to grasp the concept that the poison is always in the dose. Trace amounts of metals can be found in various food products, including vegetables and chocolate, as lead and cadmium are natural elements present in the earth's crust. Kantha Shelke, a senior lecturer on food safety at Johns Hopkins University, highlights that complete avoidance of these elements is impossible, as they naturally occur in our environment.

Safety Standards and Daily Threshold

Rather than total avoidance, it is crucial to adhere to safety standards that define acceptable levels of metal consumption. European safety standards, which are often more stringent than those in the United States, state that consuming less than 21 micrograms of cadmium per day is considered safe. Staying below this threshold ensures that the potential risks associated with metal exposure are minimized.

Determining Metal Content

To make informed choices about dark chocolate consumption, it is helpful to have access to information about the metal content in various brands. A reliable resource is this website, which showcases the levels of metals in many popular chocolate brands. By referring to this resource, consumers can evaluate whether their preferred dark chocolate falls within the acceptable range of metal content.

CR's Chocolate Test Results

We tested 28 dark chocolate bars for lead and cadmium. To determine the risk posed by the chocolates in CR’s test, we used California's maximum allowable dose level (MADL) for lead (0.5 micrograms) and cadmium (4.1mcg). Shown are the percentages of the MADL supplied in an ounce of each chocolate. Our results indicate which products had comparatively higher levels and are not assessments of whether a product exceeds a legal standard. We used those levels because there are no federal limits for the amount of lead and cadmium most foods can contain, and CR’s scientists believe that California’s levels are the most protective available. While both cadmium and lead pose serious health risks, products within each category are listed in order of lead level, because that heavy metal poses particular concerns and no amount of it is considered safe.

Milk Chocolate: A Lower-Risk Alternative

For those who prefer milk chocolate, there is less cause for concern regarding metal content. Milk chocolate typically contains a lower proportion of cocoa, which reduces the likelihood of higher metal concentrations. Thus, individuals who favour milk chocolate can enjoy their treatment with a reduced potential for elevated metal exposure.


This New York Times article summarises it very well too but in conclusion, the dark chocolate controversy surrounding the presence of metals emphasizes the importance of understanding the dose, natural elements, and safety standards associated with these substances. While trace amounts of metals can be found in various foods, including dark chocolate, adhering to daily thresholds and staying informed about the metal content of specific brands can help mitigate potential risks. By making informed choices, consumers can continue to relish the rich flavours of dark chocolate while prioritizing their health and well-being.


  1. Consumer Reports. (n.d.). Lead and cadmium in dark chocolate. Retrieved from: [Link to reference 1]

  2. Montes-Bayón, M., et al. (2017). Cadmium and lead in chocolates: Overstepping the boundaries of food safety. Food Additives & Contaminants: Part A, 34(2), 176-185. DOI: [Link to reference 2]

  3. European Food Safety Authority. (2011). Cadmium dietary exposure in the European population. EFSA Journal, 9(2), 1975. DOI: [Link to reference 3]

  4. As You Sow. (n.d.). Toxic Chocolate. Retrieved from: [Link to reference 4]


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