I love writing upbeat articles about how eating more whole plants can benefit your health and help the environment. And I get excited to spread the word about healthy pleasures — things that taste good, feel good, and do good for our bodies and for our world.

But then there are topics like this. “Inconvenient truths” that I’d prefer didn’t exist. So here it is: Dark chocolate, one of the most beloved foods by health enthusiasts and gourmands alike, has a serious heavy metal problem.

You may, like many other people, have a special place in your heart for chocolate, in general, and dark chocolate, in particular. It’s a delightful treat. It can lift your mood. It’s rich in antioxidants and other powerful phytochemicals linked to good health.

However, recent studies have unveiled a disconcerting truth: Certain dark chocolate products contain worrisome levels of two hazardous heavy metals — lead and cadmium. These metals can cause a variety of health complications in people of all ages.

And in case you were thinking, “Well, that’s too bad, but I buy only the finest quality and highest cacao, organic dark chocolates,” I’m sorry to burst your bubble. Some of the most contaminated chocolates are popular organic varieties. And the higher the cacao content, the more cadmium and lead they are likely to contain.

When I first heard about this issue, I wanted to know: “Who’s putting toxic heavy metals into my dark chocolate? And how can we stop them?”

Unfortunately, it’s not a simple problem to solve. Lead and cadmium both occur naturally in the earth’s crust, and cadmium, in particular, exists in soil. Humans have made things much worse, however, through activities like mining, manufacturing, transportation, and agriculture. Modern-day levels of these metals have not only been increasing in soil but also in water and air.

Cadmium is a harder problem since it originates in the soil. Chocolate companies can make a dent by conducting soil surveys to measure cadmium in various soils and can then choose to source more beans from regions with lower levels of this element.

In some cases, cadmium-heavy soil can be treated, or even removed to make room for cleaner soil.

And since cadmium accumulates as trees age, cacao farmers are urged to replace older cacao trees with younger ones.

But while the chocolate industry grapples with this problem by altering its harvesting and manufacturing processes, there are things you can do to reduce your exposure to heavy metals in chocolate. These strategies include maintaining a diverse diet in which dark chocolate plays a small part, choosing chocolate brands with lower heavy metal levels, and limiting children’s chocolate consumption.