Organic And Regular Dark Chocolate Contaminated By Lead And Cadmium， Study Finds

Dark chocolate and similar cocoa products are contaminated with lead and cadmium， two neurotoxic metals that are linked to cancer， chronic disease， or reproductive and developmental issues， especially in children， a new study found.

As natural elements in the Earth’s crust， lead， cadmium and other heavy metals are in the soil in which crops are grown and thus can’t be avoided. Some crop fields and regions， however， contain more toxic levels than others， partly due to the overuse of metal-containing fertilizers and ongoing industrial pollution.

However， despite growing on land with fewer pesticides and other contaminants， organic versions of dark chocolate had some of the highest levels， according to the study published Wednesday in the journal Frontiers in Nutrition.

Dark chocolate is known for being rich in plant nutrients called flavonoids， antioxidants and beneficial minerals and has been linked to improved cardiovascular health， cognitive performance and less chronic inflammation.

The research team examined only pure dark chocolate products as they contain the highest amount of cacao， the raw， unprocessed part of the cacao bean. Candies or baking chocolates with other ingredients were eliminated. The study did not disclose the names or manufacturers of the tested products.

The new study analyzed 72 consumer cocoa products for levels of lead， cadmium and arsenic. Compared with prior studies， which have looked at heavy metals in chocolate during a snapshot of time， the latest study tested the products over an eight-year period， in 2014， 2016， 2018 and 2020.

Of the six dozen chocolate products tested over the course of the study， 43% exceeded the maximum allowable dose level for lead as established by California’s Proposition 65， while 35% exceeded the Prop 65 maximum allowable level for cadmium， researchers found. The study found no significant levels of arsenic.

Over time， consuming low levels of cadmium can damage the kidneys. The Environmental Protection Agency calls the metal a probable human carcinogen.

There is no safe level of lead， especially for children， according to the World Health Organization.

“In particular， lead can affect children’s brain development， resulting in reduced intelligence quotient （IQ）， behavioural changes such as reduced attention span and increased antisocial behaviour， and reduced educational attainment，” WHO states on its website.

However， for healthy adults， risk analysis found little to worry about choosing to indulge in 1 ounce of dark chocolate now and again.

一项新研究发现，黑巧克力和同类的可可产品受到铅和镉这两种神经毒性金属的污染。（剩余889字）