New research shows that popular spice brands contain concerning levels of toxic heavy metals. Credit: Linda Coan O'Kresik / BDN

Spices might be bringing more than flavor to your cooking. New research shows that popular spice brands contain concerning levels of toxic heavy metals.

Consumer Reports, a nonprofit organization dedicated to independent product testing and consumer advocacy, released a study testing the levels of heavy metals in 15 types of dried herbs and spices — 126 products in all — from national brands such as Walmart’s Great Value, McCormick, Morton & Bassett and Trader Joe’s.

Roughly one-third of the tested products, 40 in total, had high enough levels of arsenic, lead and cadmium to pose a health concern for children when regularly consumed in typical serving sizes. Many had high enough levels to raise concern for adult consumers as well.

Frequent exposure to even small amounts of lead, arsenic, cadmium and other heavy metals is dangerous because it is difficult for the human body to break them down or excrete them. Over time, exposure to heavy metals has been linked to increased risk of behavioral problems and lower IQ in children, as well as issues with the central nervous system, reproductive system, kidneys and immune system in adults.

“I think heavy metals are getting more attention in the media since some baby foods were found to be high in heavy metals, and some foods and spices are not really regulated or regularly tested for heavy metals,” said Beth Calder, food science specialist and associate professor at the University of Maine Cooperative Extension.

Heavy metals can enter herbs and spices if the water or soil where food is grown contains them naturally or is contaminated because of pesticides or industrial uses. They may also get into packaged spices from processing equipment or packaging.

The results varied across herbs, too. For thyme and oregano, all the brands tested had levels that the study says are concerning. In 31 products, levels of lead were so high that they exceeded the maximum amount anyone should have in a day.

A single serving of any herb or spice is unlikely to cause harm, but some of the products were found to contain enough heavy metals — even in the small amounts used in cooking — to raise a concern if used regularly. Smaller amounts of certain spices could be worrisome if they are combined with others in a recipe.

Luckily, many products performed well in the tests. In seven of the 15 types of spices tested, all the brands had heavy metal levels below our thresholds for concern, and in most others, at least one brand was found that fit into the study’s “No Concern” category.

Concerned consumers don’t have to eat bland food forever, though.

Choose products with the lowest levels of heavy metals. The Consumer Reports study found at least one product that fit in the “No Concern” category for every spice and herb it tested except oregano and thyme.

New research shows that popular spice brands contain concerning levels of toxic heavy metals. Credit: Linda Coan O'Kresik / BDN

Following their recommendations can help keep heavy metals out of your spice rack. Consumers can also focus on spices and herbs that are lower in heavy metals, such as black pepper, coriander, curry powder, garlic powder, saffron, sesame seeds and white pepper.

Don’t assume some brands are safer than others, either. Calder said the U.S. Department of Agriculture’s organic standards do not include heavy metal testing. In the study, labels “organic” or “packed in USA” weren’t a guarantee that the product was safe, nor were specific brands consistently safe across all spices.

Concerned consumers can also grow and dry their own herbs and spices. Based on the Consumer Reports study, this might be an especially good idea for basil, oregano and thyme, as almost all the brands tested were high in heavy metals.

Calder said that while you are avoiding heavy metals in your spices, consider other potential sources of heavy metals in your daily life as well.

“Most important for Mainers to lower heavy metals exposure is to be sure that if they have well water to have it tested for heavy metals such as lead to ensure that they aren’t being exposed to heavy metals through their drinking water, which can be a much more serious exposure,” Calder said. “A water filter will be helpful to add to their water system if their well water does have high levels of heavy metals.

“Also, be mindful of purchasing children’s cereals and fruit juices that have been tested and have been found to have low levels of heavy metals, such as arsenic,” she said.