Zero Tolerance

“Can’t you just pick the croutons off?” No. “Surely a little bit won’t hurt?” It might. “You ate it last time and seemed fine.” That’s not how this works. Zero tolerance isn’t perfectionism or anxiety — it’s an accurate description of how coeliac disease operates at a biological level.

Why Trace Amounts of Gluten Matter in Coeliac Disease

Coeliac disease is an autoimmune condition. When someone with coeliac disease ingests gluten — even a small amount — the immune system recognises it, mounts a response, and that response damages the intestinal lining. There is no lower threshold below which this process stops entirely. There is a regulatory threshold (20ppm) below which ongoing damage is considered clinically insignificant for most people. But that’s a legal standard, not a biological off switch.

The practical implications are real:

“Just a little bit” is a real exposure. A crouton on a salad, a breadcrumb on a plate, a shared pasta water, a sauce thickened with flour — these are not negligible quantities for someone whose immune system responds to gluten. The amount required to trigger intestinal inflammation in coeliac disease is small. Research suggests daily exposure to as little as 50mg of gluten can cause measurable damage over time.

Symptoms don’t reliably indicate damage. This is one of the most important and least understood facts about coeliac disease. Some coeliacs get violently ill from trace amounts. Others feel nothing from exposures that still damage their gut. The absence of symptoms after eating gluten is not evidence of tolerance — it’s evidence of a variable symptom response. The intestinal damage can continue silently.

The cumulative effect matters. One small exposure might not cause obvious short-term harm. Regular small exposures add up over weeks and months, maintaining low-grade inflammation and slowing or preventing gut healing.

Zero tolerance, in practice, means: certified gluten-free products, careful label reading, asking about preparation in restaurants, and not treating the 20ppm threshold as a permission slip to eat food of uncertain status. It also means advocating for yourself in social situations where others find the dietary requirements inconvenient — because the alternative is ongoing harm to your health.

That’s not anxiety. That’s knowing how your immune system works.

What This Means for You

You will encounter people who don’t understand why trace amounts matter. This is the explanation. A strict approach isn’t optional or overcautious — it’s the basis of managing coeliac disease effectively.

Related in the Coeliac Alphabet: Parts Per Million · Cross-Contact · Certified vs Naturally GF · back to the full A–Z.