Both dark chocolate and bone broth contain lead to some extent. But the question is how much? And does the benefits outweigh the risks?
The cocoa in dark chocolate have been touted as healthy due to its antioxidants and flavanol content. Studies have shown that flavanol improves cognitive functions in elderly. But much of the flavanol are destroyed to more or less extent by the commercial manufacturing process of producing it into bars. However, the CocoaPro used in the study was able to elicit cognitive improvements[reference]
WashingtonPost did article about the lead in chocolates. Lead we know is not healthy for the brain and can lower IQ’s of children.
A non-profit tested some chocolate products and found lead and cadmium and noted …
“As You Sow began extensive independent laboratory testing of 42 chocolate products for lead and cadmium. We found that 26 of the chocolate products (~62%) contain lead and/or cadmium at levels in which one serving exceeds the California safe harbor level for reproductive harm.”
Lead and cadmium are naturally found in the soil and then gets into the plants (such as the cocoa plant) in which chocolates are made from. Whether this is a high enough amount to be concerned with is debatable. Humans are able to handle a small amounts of heavy metals. However, some individuals dextoxify poorly than others due to genetics.
Similarly bone broth comes from bones of chicken and beef which naturally contain lead.
Chris Kresser writes article about it. And indeed study does show lead in bone broth. But he also says …
“certain nutrients like calcium, iron, vitamin D, vitamin C and thiamin (B1) have a similar protective effect against lead toxicity.”
Chicken bone broth has 7 microgram per liter of lead. While chicken broth without bones had 2.3. And tap water has less than one microgram per liter of lead.
While chocolate and bone broth may have some health benefits, don’t over do it and eat in moderation (especially for individuals that can not detoxify metals well or have low nutrient status that protects against lead toxicity).