Just in time for Valentine’s Day, chocolate is under attack. The hysteria started when Consumer Reports published test results for some dark chocolate bars. Cadmium levels in some of those bars were judged to be too high. Should you care about this?
Before you throw out all your expensive chocolate bars, get a cadmium reality check.
- Cadmium is a natural metallic element, atomic number 48.
- Cadmium occurs naturally in soil and rocks. This is nothing new.
- Cadmium is absorbed into plants from soil, and ends up in our food supply. This is nothing new either. The amount of cadium in a plant depends on local soil concentrations. Soil in some locations has more cadium than others, so plants grown in higher cadmium areas will absorb more of the mineral.
- Cadmium is not well absorbed from food. In other words, you aren’t likely to absorb all of the cadmium you might consume in food or water. Factors that impact absorption aren’t well known, but intake of other minerals like calcium or zinc may reduce cadmium absorption.
- The National Health and Nutrition Examination Study (NHANES) measured cadium levels in several thousand study subjects and found that everyone has measurable cadium in blood.
- Cigarette smoke and certain industrial processes increase cadmium exposure for some people.
Any cadmium in chocolate was absorbed from the soil into the cacao beans. It was not added by chocolate candy manufacturers.
Do we all have detectable cadmium because of chocolate? No. In fact the biggest cadmium food sources are:
- leafy vegetables
- legumes and nuts
- root vegetables (carrots, turnips, parsnips, rutabagas…)
Shocking! That study doesn’t even mention chocolate. Why didn’t Consumer Reports warn us about bread, oatmeal, peanut butter and lettuce? Why didn’t Consumer Reports warn us about cadmium in FLAX!
Yes flax, that Health Halo food that’s promoted as a superior source of fiber and healthy fats. ConsumerLab (subscription required) tested several brands of flax seed and found some with “4 to 5 times as much cadmium as others”, probably due to soil differences.
How much cadmium is too much?
Whether flax or chocolate or other foods, the discussion is complicated. There isn’t any good data linking a specific daily intake of cadmium to a specific disease. We’re left with guesswork. The European Food Safety Authority set a “Tolerable Weekly Intake” of 2.5 micrograms cadmium per kilogram body weight. That calculates to a weekly cadmium limit of about 170 micrograms for a 150 lb person (about 24 micrograms/day). The U.S. has not established limits on cadmium in foods. According to the NHANES data, average daily intake in the U.S. is about 4.6 micrograms/day.
OK, TMI on the cadmium numbers. But you get the point: cadmium risks and dietary exposure are poorly understood and all over the map, literally and figuratively. Speaking of which, in California, a food with more than 4.1 micrograms cadmium/serving must have a warning label. No other states require any such warnings.
Back to Chocolate
Here’s an interesting fact: acidic and volcanic soils are higher in cadmiun. Latin American countries have more acidic soil compared to West African countries, so cacao beans from Latin America tend to have more cadmium than African varieties.
Again, cadmium levels in cacao beans are not impacted by fertilizer, local pollution or industrial practices. It’s all about the soil. And strangely, many of the chocolate bars with the highest cadmium content were organic. Go figure.
What to do?
- If you’re terrified of cadmium, don’t eat chocolate. But then, you’ll need to avoid all those other higher cadmium foods like bread, pasta, lettuce, peanuts, potatoes and flax.
- Another option is to stick to milk chocolate. Cadmium is higher in dark chocolate, because dark chocolate has higher cacao bean content.
- You could research the source of cacao beans in certain products and stick to chocolate bars sourced from Africa.
- You could be realistic. How much dark chocolate do you eat in a week? Really dark chocolate, not the pale chocolate-like coating on candy bars.
I don’t eat a lot of chocolate, so I’m not concerned for myself. If you enjoy really wonderful chocolate truffles once a year around Valentine’s Day, go ahead and enjoy. Just avoid truffles stuffed with flax!
Side Note: I searched the word “risk” in The Consumer Reports scary chocolate article. This relatively short article had the word “risk” 14 times. They really know how to gin up a controversy.