Yes, I do have some patients who do not tolerate quinoa. A couple of things to bear in mind: Quinoa, quinoa flakes, quinoa pasta and any processed food that contains quinoa should be labeled gluten-free. This is true for ANY gluten-free grain or alternative grain (such as quinoa, sorghum, amaranth, millet, and teff) with the exception of plain rice or plain wild rice. These foods are easily contaminated by gluten-containing grains in the field, and during transport, milling and packaging.  In a study by Tricia Thompson et al, 32% of the gluten-free grain samples (not labeled gluten-free) contained mean gluten levels >/=20 ppm which is not considered gluten-free under FDA gluten-free labeling law.¹  

But, what if the quinoa is labeled gluten-free (or certified gluten-free)? Then what? The quinoa seed contains a high concentration of a naturally occurring, bitter tasting coating called saponin, named for how it lathers up in water, like soap suds. Plants use saponin as a natural pest control; when ingested by humans, it may cause stomach aches. The best solution is to rinse and drain raw quinoa before cooking. It is not necessary to rinse quinoa pasta, quinoa flakes, etc., as the manufacturer has already done so.

Directions on How to Rinse Quinoa and Two Yummy Recipes:*

From dietitian and Chef Kristine Kidd:
“Measure the quinoa right into the pan it will cook in. Cover generously with cold water, swish it around a few times and pour the water and quinoa into a fine strainer. Return the grains to the pan and repeat 3 more times. This takes about 1 minute total.”
http://kristinekidd.com/kkidd/kristinekihttps://kristinekidd.com/quinoa_super_delicious_super_easy_super_sixbraised_chicken_with_red_bell_peppers_and_lemon/dd/2013/03/quinoa-super-delicious-super-easy-super-sixbraised-chicken-with-red-bell-peppers-and-lemon.html

From Chef Carol Fenster: “Rinse quinoa in a sieve, rubbing the grains between your fingers. Drain and repeat until the water runs clear.”
http://savorypalate.com/index.php/quinoa-tabbouleh/

What if you already rinse your quinoa? Some people are sensitive to the high fiber content of quinoa. One cup of cooked quinoa contains 5 grams of fiber; the same amount of white rice contains <1 gram. The gut needs time to adjust to new or increased fiber sources. Try reducing the amount of quinoa eaten at one serving and note any changes in bowel movements. In addition, look at the amount of fiber you are consuming from other sources (fruits, veggies, lentils, dried beans, chick peas, other gluten-free grains, nuts, and seeds) at the same meal. Fiber is very important in the gluten-free diet because it offers so many gut and heart benefits, but it is always best spaced through the day, with plenty of water. Quinoa flakes are lower in fiber than quinoa seeds and can help you adjust to eating more fiber. They also make a great hot breakfast cereal mixed with blueberries or other fruit, cinnamon, and gluten-free labeled walnuts and chia or ground flax seeds.

If it’s not a fiber issue, then it could be an intolerance to quinoa, just as it could be with any food. Less likely is the possibility of a true food allergy. An allergy to quinoa has been exceedingly rare in my practice.

I don’t believe it’s possible to make a blanket statement that quinoa (or any grain, for that matter) is “totally safe” because so many factors involved in food production, storage and, in particular, testing differ among manufacturers. When a product is labeled gluten-free, the manufacturer must follow the gluten-free labeling law which requires that the product itself contains <20 ppm gluten per serving. A certified gluten-free product should have a gluten level below the level set by the certifying organization.²  It’s up to the manufacturer to follow the appropriate practices, choose the appropriate test, and test often and rigorously enough to maintain those standards.

In nutrition clinic, I go through the above scenarios with my patients. If quinoa remains an issue, we will work together to find alternative gluten-free grains (if tolerated), other sources of fiber and protein, and, if needed in specific cases, a grain-free, gluten-free diet that balances vitamin, mineral, carbohydrate, protein, fat and fiber needs.

1. Thompson T, Lee AR, Grace T. Gluten contamination of grains, seeds, and flours in the United States: a pilot study. J Am Diet Assoc. 2010 Jun;110(6):937-40.
   https://www.ncbi.nlm.nih.gov/pubmed/?term=Thompson+T+contamination+gluten+free+grains.
2. CeliacNow.org. Third Party Certification of Gluten-Free Foods. https://www.bidmc.org/-/media/files/beth-israel-org/centers-and-departments/digestive-disease-center/celiac-center/_certificationofgffood-9-12-18.ashx?la=en&hash=049F15860C865B70CCAF216384E69AE06236AAEE.

*Disclosure: Both Kristine Kidd and Carol Fenster have shared their cookbooks and recipes with me for my Delete the Wheat nutrition retreats in the past.

Reviewed and updated October 4, 2022.