There is indeed evidence that it's possible. One medical study backs the idea that it's possible to experience celiac disease symptoms by inhaling gluten, rather than eating it. In addition, there's anecdotal evidence that airborne gluten can cause symptoms. So while airborne gluten has not been proven to cause problems, if you have celiac disease and continue to have symptoms despite following a gluten-free diet, it would make sense to look for possible airborne sources of gluten in your environment.
The medical report, published in the New England Journal of Medicine in 1997, involved two farmers diagnosed with nonresponsive celiac disease (also known as refractory celiac disease).
Each day, the two spent time in an enclosed space, feeding their cattle a mixture of barley, wheat and other grains that contained at least 6% dust particles by weight. The report estimates that the two farmers "were potentially exposed to over 150 g of gluten-containing dust particles per day, which they were inhaling and ingesting."
For reference, that's about 15,000 times the amount of gluten considered "too much" on a daily basis for a person with celiac disease.
Both farmers suffered from ongoing symptoms, including cramps, bloating, fatigue and diarrhea. One of the farmers the one with the worst symptoms had total villous atrophy, despite following the gluten-free diet. The other, who also followed a gluten-free diet, showed less severe intestinal damage.
Once both farmers began wearing face masks, their symptoms cleared up. The farmer with the more severe intestinal damage saw improvement in his intestinal lining, and the other farmer had total resolution of the damage.
What Does This Mean for Other Celiacs?
Most of us aren't farmers, nor are we exposed to that much gluten each day, either from gluten in "gluten-free" foods or airborne gluten. However, it shows that airborne gluten can have an effect and cause symptoms.
For non-farmers, there aren't any medical studies that show airborne gluten can be a problem. However, anecdotal evidence suggests you can get glutened from airborne flour, either in a private kitchen or even near an active grocery store bakery. This has happened to me more times than I can count, and it's happened frequently to celiac and gluten-intolerant friends. You don't have to be super-sensitive, either.
Pet food may pose a potential problem, according to the clinicians who wrote the airborne gluten medical report. Most dry pet food contains gluten, and when you pour it out, it's possible to inhale some of it. In addition, some powdered household products, such as drywall compound, contain gluten, and working with these may cause a reaction. I've had bad reactions from drywall dust.
How to Avoid Airborne Gluten
To avoid airborne gluten, you need to know where it occurs. Here are some suggestions, both from my own experience and from other celiac educators:
- Never use flour in the kitchen. Don't work with flour; don't let anyone else work with flour in your kitchen; and don't visit with friends and family members in their kitchens while they're working with flour.
- Switch to gluten-free pet food. It's theoretically possible for you to avoid the dust if a) someone else feeds your pet, and b) you keep the food and the bowl outside. But if you have a close relationship with your pet, you'll be better off switching anyway, since you'll inevitably be exposed.
- Avoid places where drywall is being installed. If you need to have work done on your house, have someone else do it and stay away until the work site's been thoroughly cleaned up. Don't use ready-made spackling putty or compound, either, since most are wheat-based.
- Exercise caution around store-based bakeries. Some of these seem fine for me, while others get me every time. I think the difference may be in the ventilation systems. If you can smell the bread and cookies baking, you may be risking an airborne reaction.
- Consider using a face mask in certain situations. I haven't had great luck with a face mask when I've tried to use it to avoid drywall dust. I still got a reaction it just took longer. But for short exposures, it might do the trick. I recommend a full respirator, rather than a painter's mask they're about $40 in home improvement centers. If you have asthma or another respiratory condition that affects your breathing, you should use a respirator with caution and remove it if you have trouble breathing with it on.
Not everyone needs to take all these precautions; if you're not particularly sensitive to gluten cross-contamination, you may be fine in most or all of these situations. But if you find you're still having unexplained symptoms, even though you follow the gluten-free diet very strictly, you might want to check out your environment as well as your food.
Kasim S. et al. Nonresponsive Celiac Disease Due to Inhaled Gluten. New England Journal of Medicine 2007; 356:2548-2549.