One of the most common questions I come across is, “how do I know if I have non-celiac gluten-sensitivity (NCGS)?”
While celiac disease is estimated to account for about 1% of the population, NCGS is estimated to affect 6%. Celiac is a genetic autoimmune disease, while NCGS is a food sensitivity, meaning that each condition affects the body differently and carries its own set of unique, long-term risks. That said, they share the same trigger, gluten, and MANY of the same symptoms, which is what makes it so confusing to know if you have one or the other. You can read more about the differences and similarities here.
How to Determine if it’s NCGS
The most important part of the process is to first test for celiac and wheat allergy. That’s because NCGS is diagnosis of exclusion, meaning you have to rule out other gluten-related disorders BEFORE you can be sure it’s NCGS.
Here’s the catch: In order to get an accurate celiac test, you have to be consuming gluten. Many people at the point where they’re wondering if they have NCGS have already eliminated gluten. We’ll discuss this scenario more in a minute, but if you’re someone who is in the early stages of troubleshooting gluten, DON’T PUT THE BREAD DOWN JUST YET!
Typically, to get a solid test result for celiac, you’d have to be eating 2-3 servings of a gluten-containing food for 6-8 weeks before. In some cases, individuals can get tested sooner if they cannot tolerate that long of a challenge.
If the celiac test comes back negative and the wheat allergy test does too, it’s time to consider NCGS.
The next step is to do an elimination/reintroduction challenge (ideally under guidance) to confirm NCGS. I usually have my clients eliminate gluten for at least 3 weeks before challenging it. If symptoms disappear during the elimination period but return when gluten is reintroduced, this indicates NCGS.
What do I do if I’ve already eliminated gluten? A gluten challenge sounds awful!
I hear ya. It’s a personal decision whether or not you want to do a gluten challenge, but if you decide to go for it, please do so under guidance! If it sounds far too uncomfortable to bear, then there are a couple more options.
Genetic Testing: There are two genes that predispose people to celiac: HLA-DQ2 and HLA-DQ8. Celiacs have either one or both of these (although it is worth noting that these genes simply indicate risk of developing celiac; they are not a guarantee that you actively have it). You can ask your doctor for a blood test to check for these. If you do not have either of these genes, that rules out celiac and is a substantial indicator of NCGS.
Consider living like a celiac: Especially if you know you aren’t looking out for cross-contact (otherwise known as cross-contamination) and are still having symptoms. Celiacs must be very vigilant about trace amounts of gluten from things like shared kitchen equipment and food prep spaces. For example, restaurants with shared kitchens that have a gluten-free menu is not enough of a safeguard for celiacs. If you hadn’t been taking these precautions before, they could be worth implementing.
Places you will not find an accurate NCGS diagnosis:
- Your allergist – They test for true allergies that are mediated by IgE antibodies, which do not show up in NCGS
- “Food Sensitivity” IgG Blood Panels – In general, these are not validated as accurate enough and often give false positives
- Hair, saliva, urine, or fingernail analysis – A big no.
Final Thoughts
Both celiac and NCGS can manifest in serious ways and with symptoms that interfere with life on physical, mental, and emotional levels. Make sure your healthcare team is aware and up-to-date about gluten-related disorders to ensure that accurate diagnostic testing and comprehensive follow-up is being done.
If you’re still working on your confidence around GF eating and living, I invite you to find out more about my Gluten Free Jumpstart Program. Over 6 weeks, I help you build a foundation of skills in avoiding gluten and taking care of your gut that every celiac and gluten-sensitive individual needs to know!
As with everything on this website, this is for educational purposes only and is not a substitute for medical advice. This information is not intended to treat, cure, diagnose, or prevent any condition. Please always consult with your doctor.