Cross-contact: what actually matters

By contrast, fewer than 2% of packaged foods exceed the regulatory limit. If you are budgeting worry, this is where it belongs.

Staff knowledge is the underlying cause. In one 2025 study of 397 food-service employees, 87.5% had never received formal allergen training and fewer than 2% scored above 50% on allergen knowledge. In a separate study, culinary students who had just completed three hours of allergen training still produced an unsafe gluten-free dish.

Shared toasters test clean. Researchers toasted 40 gluten-free slices in toasters previously used for wheat bread and every sample stayed under 20 ppm. Ordinary dishwashing was sufficient to clean shared utensils.

Shared pasta water is a real risk and one of the few home practices the same study flagged.

Kissing is fine. A 2026 study had partners eat 590 mg of gluten; 18 of 20 kisses left saliva under 20 ppm and produced zero symptoms. Drinking four ounces of water first eliminated every exceedance.

The widely repeated claim that airborne flour stays suspended for 12 to 24 hours has no primary research behind it that we could locate. Treat all such durations as folk guidance rather than measurement.

Vigilance is not free. Adults rated as extremely vigilant score 64.2 on quality of life against 77.2 for others, a 13-point deficit, while demonstrating greater disease knowledge. They are no safer for it, and they are more miserable.

Screening studies find avoidant/restrictive food intake disorder in 14% to 57% of celiac patients depending on the instrument, with no corresponding benefit to dietary adherence or intestinal healing. Separately, 58% of patients self-eliminate additional foods with no diagnosis justifying it, and 77% of those score above the clinical cutoff for depression.

Both directions are harm. Missing gluten makes people sick, and inventing gluten narrows an already narrow diet and damages quality of life.