Research by Yanus et al. assessing the human risk of trace metals in chocolate said that although the lead concentration found in a variety of global brands analyzed was below the US Pharmacopeia (USP) 1,000 ng/g limit, the lead concentration should, “still be considered a health concern”.
Risk exceeding daily limit
“Children, who are big consumers of chocolates, may be at risk of exceeding the daily limit of Pb [lead], due to their low body weight and higher digestive tract uptake,” said the Israeli researchers.
“They may be vulnerable to lead exposure from these products – one cube of dark chocolate can contain up to 20% of the lead oral limit; furthermore chocolate may not be the only source of lead in their nutrition thus increasing the risk of exceeding the daily limit.”
The same risk does not apply to adults, whose digestive absorption of metals is poor.
The more cocoa solids, the more lead
The research found a correlation between a high cocoa solid content and high levels of lead.
“In large quantities it is preferable for children to eat milk or white chocolates than eating dark chocolates [which have a higher cocoa solid concentration],” said the study.
Earlier research has shown that lead takes a long time to exit the body and in a short time can cause health problems in children including vomiting, constipation and weight loss as well as behavioural changes, slowed growth and memory and impaired language development.