Report Finds Extreme Lead Levels in Gluten-Free Cassava Products

If you’re on a gluten-free diet, you’ve likely come across cassava. This starchy root vegetable (also known as yuca, manioc, or arrowroot) is commonly used in bread, pasta, chips, and cookies due to its naturally gluten-free profile and potential gut health benefits. However, this week, Consumer Reports released its latest investigation, which found that many cassava products contain alarmingly high levels of lead.

In the report, the nonprofit reviewed 27 cassava-based products, finding that more than two-thirds of them had a single serving that exceeded the level of lead deemed acceptable by Consumer Reports’ food safety experts — some by more than 2,000%.

“Some of these cassava products had the highest level of lead that we’ve ever tested, and I’ve been with Consumer Reports for eight and a half years,” James Rogers, PhD, the director of food and safety research and testing at Consumer Reports, told Food & Wine. “We never want consumers to panic, but we do want them to be aware so they can take proper measures to reduce their lead intake, since long-term lead exposure can lead to adverse health outcomes.” 

Here’s a closer look at the report’s results, plus how to mitigate your risk of lead exposure. 

What did the report find?

Cassava is marketed as a gluten-free, gut-friendly alternative to traditional grain-based products, but that doesn’t mean it’s free from health concerns, environmental pollution, or manufacturing contamination. This is because root vegetables, including cassava, grow in the ground and are known to absorb heavy metal contaminants such as lead, which are commonly found in the environment.   

According to the report, cassava flour and products made from it had the highest levels of lead. The reason for this is likely that cassava flour is produced by grinding the whole, fresh, peeled root, and this process could potentially concentrate any lead that may have been present in or on the vegetable.

Of the seven cassava flours tested, four had levels so high that Consumer Reports advises against consuming them in any quantity, since a ¼-cup serving a day contained between 1,000 and more than 2,300% of concerning lead levels (0.5 micrograms). The three remaining cassava flours tested had between 200 and 600% of that level per serving, suggesting they should be limited but are safe in moderation. Continuous lead exposure has neurological effects on baby and child development, but it can also cause high blood pressure, kidney problems, nerve damage, and reproductive issues in adults.

Cassava chips also had high levels of lead, according to the report. Of the eight tested, two should be completely avoided, and one can be eaten occasionally, since lead levels in an ounce of these chips ranged from 600 to 1,700% of the levels of concern.

Cassava and lead contamination test results 

Consumer Reports tested 27 different foods that contain cassava as a primary ingredient – including chips, flour, crackers, bread, cookies, cereal, pasta, puff snacks, bars, and soda – for heavy metals such as arsenic, cadmium, mercury, and lead.

Mercury was not detected in any product. Although measurable amounts of arsenic were found in about half of the tested foods and cadmium in most of them, the levels in one serving of the product were far below levels of concern.

As for lead, here’s what the nonprofit found:

Products to Avoid	OK to Eat Occasionally	Better Choices
Bob’s Red Mill Cassava Flour	Artisan Tropic Cassava Strips Sea Salt	Bettergoods (Walmart) Finely Ground Cassava Flour Guacamole Flavored Tortilla Chips
Otto’s Naturals Organic Multi-Purpose Cassava Flour	Pamela’s Organic Cassava Flour	Siete Grain Free Cookies Mexican Wedding
Quay Naturals Premium Cassava Flour	Otto’s Naturals Grain-Free Ultimate Cookie Mix	Cult Crackers Crunchy Cassava Crackers
365 Whole Foods Market Sea Salt Cassava Tostone Cassava Chips	Iberia Yuca Cassava Chips Lightly Salted	Unreal Dark Chocolate Coconut Bars
Jovial Organic Grain Free Cassava Spaghetti	LesserEvil “No Cheese” Cheesiness Paleo Puffs	Lovebird Organic Grain Free Cereal Honey
Terrasoul Superfoods Cassava Flour	Barnana Organic Cassava Chips Himalayan Pink Salt	Simple Mills Fine Ground Sea Salt Almond Flour Crackers
Thrive Market Cassava Chips Sea Salt	Tonomi Cassava Flour	Goya Yuca Cassava Chips
	MadeGood Star Puffed Crackers Cheddar Flavor	Olipop Vintage Cola
	Goya Casabe Cassava Bread
	La Fe Casabe Cassava Bread
	Heaven & Earth Cassava Chips

How to mitigate risk 

Even though no amount of lead is considered safe, there’s no need to panic if you’ve snacked on one of the above products. “The negative effects of lead happen over time when there’s chronic exposure, so you won’t get lead poisoning if you eat one serving of these products,” Rogers says. “However, I would strongly urge consumers to reconsider using the seven products we listed to avoid.”

Instead, Rogers suggests shopping for one of the “better choice” products. If none of those excite you, he also recommends alternative products made from buckwheat, corn, sorghum, or millet, which are also gluten-free. According to Consumer Reports’ previous testing, these options should be much lower in lead (and arsenic and cadmium) than cassava flour.

If you prefer to eat cassava in its whole form, ensure that you carefully clean and fully peel the vegetable thoroughly before consumption. This is because most of the lead in cassava plants is typically concentrated in the outer layer of the root, Rogers says.

Finally, remember that heavy metal exposure is all about mitigating your risk, so if you eat these foods on occasion, even those with the highest levels of lead are not close enough to cause serious or immediate harm. That said, if you’re ever concerned about your dietary choices or lead exposure, it’s best to talk with your doctor.