There is no such thing as 100% gluten-free diet

By Gill Hyslop

- Last updated on GMT

Despite best efforts, gluten cannot be completely avoided. Pic: ©GettyImages/manyakotic
Despite best efforts, gluten cannot be completely avoided. Pic: ©GettyImages/manyakotic
A new study suggests that people maintaining a 100% gluten-free diet are still ingesting enough gluten to cause severe symptoms and potential intestinal damage.

For the 1% of the population who have celiac disease (CD), maintaining a gluten-free diet (GFD) is imperative for good health.

However, a new study – conducted by a group of researchers from the Harvard Medical School and supported by biopharmaceutical company ImmunogenX – confirmed it may be even more difficult than previously thought to remain totally gluten free.

CD patients and those with a gluten intolerance are still eating enough gluten to trigger symptoms and perpetuate intestinal damage, say the authors.

On average, adults without CD consume between 5g and 15g of gluten per day. These are dangerous levels for CD sufferers, who are advised to consume no more than 10mg of gluten per day.

Gluten is unavoidable

Unfortunately, though, gluten is nearly impossible to avoid entirely, even for those following a strict GFD.

To determine how much gluten this group of people may be ingesting – either deliberately or accidentally – the scientists performed a meta-analysis on data from two different clinical programs.

Three methods were used to estimate gluten consumption.

The first two involved measuring the amount of gluten immunogenic peptides (GIPs) – bits of the gluten molecule that are undigested – in stool and urine samples.

A third analysis was made using data from a clinical trial of new medication for CD.

Latiglutenase is a therapeutic drug designed to break down gluten and is currently in the development phase by ImmunogenX. It is not yet available to consumers.

In this case, changes to the intestines of subjects on the treatment were examined to calculate how much gluten was removed from their typical diet.

Still too much

The researchers found people with CD on a GFD regularly consume around 150-400mg (stool test) and 300-400mg (urine test).

The analyses of the latiglutenase data for CD individuals with moderate to severe symptoms indicated patients ingested more than 200 mg per day of gluten.

According to the authors, their findings indicate that 3-19% of the CD population consume significantly more than what is considered the safe threshold (10mg/d).

They conclude that typically, celiac disease patients consume upwards of 244 mg of gluten per day, which is certainly enough to cause continued symptoms.

Where to from here?

Until this analysis, involving the measurement of gluten in urine and stool samples of CD patients, there was little basis for estimating the amount of gluten that sneaks into a GFD,” ​said Jack A Syage, PhD, CEO of ImmunogenX and first author of the study.

“The new results indicate that it is not unusual for CD patients to consume hundreds of milligrams of gluten on a given day where less than 50 mg/day is considered a safe level.

“In our minds, there were two motivating factors behind this study: (i) how much gluten is being consumed on a gluten-free diet, so we know how to design our real-world trials to provide doses that are sufficient to protect against these unintended exposures; and (ii) in gluten challenge trials, are the gluten intakes representative of real-world intrusions so that if these trials are successful one is confident it will have real therapeutic value. This is an interest of the FDA as well,”​ said Syage.


Authors: Jack A Syage, Ciarán P Kelly, Matthew A Dickason, Angel Cebolla Ramirez, Francisco Leon, Remedios Dominguez and Jennifer A Sealey-Voyksner

Determination of gluten consumption in celiac disease patients on a gluten-free diet.

The American Journal of Clinical Nutrition, Volume 107, Issue 2, 1 February 2018, Pages 201–207,

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1 comment

I think I do better than this

Posted by Victoria,

I have severe celiac disease which was made much worse by misunderstanding and mistreatment. My reactions are violent and painful, so I work hard to remain as close as possible to 100 percent gluten free.
* I eat essentially no prepared food whatsoever, no "gluten-free" baked goods, nothing canned or bottled or frozen. I do all my own cooking.
* I use only tested and verified ingredients. Most of my flour replacement comes from Bob's Red Mill, a very reputable company.
* I search out and remove other sources of gluten and allergens. For example my medications (thyroid and blood pressure) are not ready-made pills but specially compounded capsules with *only* the pure medication and Bob's Red Mill cornstarch. This costs a fortune but is necessary for my health.
* I I very rarely eat in restaurants and when I do, I check everything right down to seaasonings.

The researchers should test some highly sensitive celiacs like me to see how we are doing.
BTW the organization Coeliac UK insists that 20 ppm of gluten is "safe" and allows this much in foods labelled "gluten free" in England. This is not true for severe celiac patients like me and apparently causes a lot of people much trouble.

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