Arrowroot is naturally gluten free. It comes from the rhizomes (underground stems) of the tropical plant Maranta arundinacea, which belongs to a completely different botanical family than wheat, barley, or rye. It contains no gluten-forming proteins whatsoever, making it a safe starch for people with celiac disease or gluten sensitivity.
Why Arrowroot Is Naturally Gluten Free
Gluten is a group of proteins found exclusively in certain cereal grains: wheat, barley, rye, and their derivatives. Arrowroot is a starchy tuber crop, not a grain. The plant grows horizontally underground as a rhizome, similar to ginger or turmeric. Its starch is extracted by washing and drying the pulp of these rhizomes, producing the fine white powder sold as arrowroot starch or arrowroot flour (they’re the same product). Because the plant itself never contained gluten proteins at any stage, arrowroot powder in its pure form is completely free of gluten.
Cross-Contamination Is the Real Risk
The one caveat applies to nearly every naturally gluten-free product: manufacturing can introduce trace amounts of gluten. The FDA notes that shared harvesting equipment, transport vehicles, storage silos, and production lines can all result in “cross-contact” between gluten-free ingredients and gluten-containing grains. A facility that also processes wheat flour, for example, could inadvertently transfer gluten particles into an arrowroot product.
If you have celiac disease or a serious gluten sensitivity, look for arrowroot powder that carries a certified gluten-free label. Under FDA rules, that label means the product contains fewer than 20 parts per million of gluten, the threshold considered safe for people with celiac disease. Brands that don’t carry this certification may still be gluten free, but there’s no third-party verification of their processing environment.
How to Use Arrowroot in Gluten-Free Cooking
Arrowroot works best as a thickener. It creates a clear, glossy finish in sauces, gravies, pie fillings, and fruit glazes, which makes it preferable to cornstarch or wheat flour when you want a translucent result. It also thickens at a lower temperature than many other starches, so it’s useful for delicate sauces that shouldn’t boil.
When substituting arrowroot for wheat flour as a thickener, use about half the amount. If a recipe calls for two tablespoons of wheat flour to thicken a sauce, one tablespoon of arrowroot will do the job. For replacing cornstarch, tapioca starch, or potato starch, arrowroot swaps in at a 1:1 ratio.
Arrowroot does have limitations. It doesn’t hold up well in dairy-based sauces, which can turn slimy. It also breaks down with prolonged cooking, so it’s best stirred in near the end. And it won’t give baked goods the structure that wheat flour provides. For gluten-free baking, you’ll get better results combining arrowroot with other flours (like rice flour or almond flour) rather than using it alone.
Digestive Benefits Worth Knowing
Arrowroot has a long history as a folk remedy for upset stomachs, and there’s a small amount of clinical evidence behind it. A pilot study in patients with irritable bowel syndrome found that arrowroot reduced diarrhea, eased abdominal pain, and even had a longer-term positive effect on constipation. Researchers theorized this was related to increased fecal bulk, which helps regulate bowel movements in both directions.
This makes arrowroot a particularly appealing option for people who avoid gluten because of digestive symptoms. It’s one of the most easily digested starches available, gentle enough that it’s commonly recommended as an early food for infants and a recovery food after stomach illness. When consumed in normal food amounts, it’s considered safe for pregnant and breastfeeding women as well.
Side Effects and Sensitivities
Arrowroot is well tolerated by most people when used in typical cooking quantities. The only reported side effects are mild: occasional constipation or stomach discomfort, usually when consumed in large amounts. True allergic reactions to arrowroot are rare, though not impossible. If you’ve never used it before, starting with a small amount in a recipe is a reasonable approach. There are no known interactions with medications or common food allergens beyond the cross-contamination issue described above.