Chocolate has a dirty little secret.
Along with cocoa, sugar and all the things that make chocolate enjoyable, some chocolate products can contain tiny amounts of heavy metals.
Researchers recently tested 36 milk and dark chocolate samples from six brands for four metals: arsenic, cadmium, lead and mercury.
They then estimated how much people might be exposed to through typical chocolate consumption.
The results sound more alarming than they actually were.
The researchers found no identified health risk from cadmium or mercury under their exposure assumptions.
They also found no non-cancer risk under their central, or typical, exposure estimates. Some potential risks appeared under high-end exposure assumptions for lead, while potential cancer risks from arsenic were identified in some scenarios. But arsenic was only quantified in two of the 36 samples.
The researchers ultimately concluded that heavy-metal health risks were unlikely under typical exposure scenarios for most chocolate bars.
So should you stop eating chocolate?
Not based on this study.
There are several reasons to be cautious about drawing big conclusions from it.
The sample was relatively small. It included products from six brands rather than the entire chocolate market.
And the researchers were employees or former employees of Stantec, a consulting firm that provides scientific advice to companies and other organizations. The authors disclosed that relationship and said no outside funding was used for the study.
That’s worth knowing.
It’s also worth remembering what the study actually found.
Cadmium was detected in some chocolate, but the researchers did not identify a health risk from cadmium under their exposure assumptions.
The bigger lesson
Finding a chemical in a food isn’t the same thing as showing that eating the food causes harm.
Dose matters.
Frequency matters.
And exposure matters.
Chocolate can still be enjoyed without turning it into either a miracle food or a source of unnecessary fear.
The Watchdog takeaway
Enjoy chocolate if you like it.
But don’t assume that because something contains cocoa, more must automatically be better for you.
Evidence & Source
Evidence: Moderate. The study directly measured metals in 36 chocolate samples and modeled exposure, but the sample was relatively small and the authors disclosed employment with a consulting firm involved in scientific advice.
Source: Food and Chemical Toxicology, 2026.
Study: Food and Chemical Toxicology study (PubMed)(opens in a new tab)