Chocolate, especially dark chocolate, has many health benefits including antioxidants, anti-inflammatory compounds, and polyphenols that support heart health. But a recent study found a significant health risk in many chocolate products – toxic heavy metals like lead and cadmium.
A nonprofit agency conducted independent lab testing which found that 35 out of 50 chocolate products contained high levels of lead and/or cadmium, exceeding the threshold determined safe by California law. According to state law under Proposition 65, these chocolate bars are required to be labeled as follows – “WARNING: This product contains a chemical known to the State of California to cause birth defects or other reproductive harm.”
Unfortunately, this includes many popular dark chocolate bars from well-known brands including Trader Joe’s, Whole Foods, Ghirardelli, Hershey and others. This report corroborates earlier research with the same findings.
While the companies claim that this is an insignificant amount of lead and cadmium, the effects of these toxins is cumulative and there is no safe level of lead exposure, especially for children. The NIH reports that health effects of lead exposure in children include impaired cognition, behavioral disorders, hearing problems and delayed puberty. In pregnant women, lead is associated with reduced fetal growth. In everyone, lead and/or cadmium consumption can impact the heart, kidneys, nerves, and immune system.
But why is our chocolate contaminated with lead? Some believe that because our chocolate is made in countries that still use leaded gasoline, the atmospheric residues of this are absorbed by cocoa beans. Another study found that chocolate products pick up lead during the processing, manufacturing, and shipping phases.
Our world is connected like never before, and every choice that is made has far-reaching environmental impact. We cannot escape from the increasing prevalence of toxins in the environment, and continuous low-level exposure is ongoing for all of us. This is one of the reasons why I stress detoxification so much, both in my book and my clinical practice.
Should you stop eating chocolate? I don’t think so. But I have switched to products that don’t have elevated levels of lead or cadmium. The full report details which brands have passed the testing. While we don’t yet know the all long-term effects of low-level ingestion of heavy metals, I think we should reduce our exposure as much as possible. I’m not taking any chances.



