Eggs in their shells should be close to perfectly gluten-free, although some very sensitive people with celiac disease and gluten sensitivity have reported problems with eggs from chickens fed a heavy diet of gluten grains (more on this in a minute).
For most of us, any problems with eggs most likely stem from one of two places: gluten cross-contamination when the eggs are cooked, or from a sensitivity to the eggs themselves (eggs are one of the top eight allergens in the U.S., so it's not unusual for someone to suffer from sensitivities to both eggs and gluten).
If you're preparing your eggs in a gluten-free kitchen, you should be fine. But in a shared kitchen, you'll need to watch out for potential problems with shared cooking spaces, utensils and pans in order to keep your eggs safe. For more on this, see:
- Is A Shared Kitchen For You?
- How To Set Up A Shared Kitchen
- What Utensils and Cookware to Replace When You Go Gluten-Free
Dining Out Gluten-Free for Breakfast
When you're following the gluten-free diet and you eat eggs out, you unfortunately need to be quite careful.
Many restaurants that serve breakfast cook their eggs on the same grill as French toast and pancakes ... and that will thoroughly cross-contaminate your otherwise perfectly safe meal. In addition, some restaurants (the International House of Pancakes, for one) actually mix a little pancake batter into their scrambled eggs and omelets to make them fluffier (yikes!).
To stay safe eating eggs at a restaurant, I follow my rules for eating out safely gluten-free. Specifically, I ask that my eggs be prepared in their own, clean pan using clean utensils, as far away as possible from where any pancake batter or toast is being prepared. I've had pretty decent success doing this.
Can Gluten-Eating Chickens Produce Gluten-Containing Eggs?
Now, as I said earlier, a few people who are quite sensitive to trace gluten have reported glutenings (i.e., gluten reactions) when they eat eggs from chickens that eat mainly wheat and barley. These same people are fine when they eat eggs they obtain from farmers who don't feed their chickens gluten grains.
Now, this may seem pretty far-fetched, but there's actually a bit of scientific evidence that indicates it may be possible for proteins or protein fragments to pass from chicken feed into the eggs themselves (gluten is a protein).
An Ohio State University graduate student experimented with feeding chickens a diet high in soy protein to see if he could influence the amount of soy isoflavones (a component of soy protein) in those chickens' eggs. He found that he could: chickens fed the high-soy diet routinely produced eggs higher in isoflavones. (You can read the thesis here)
Now, obviously this experiment did not involve gluten grains. However, it's not too much of a stretch to imagine that it's possible for gluten-eating chickens to produce eggs that contain a tiny bit of gluten protein (or, more likely, gluten protein fragments).
If these eggs did have gluten in them, it would be a very small amount likely far below even 1 part per million (for comparison, foods are generally considered "gluten-free" if they contain fewer than 20 parts per million of gluten, or are less than 0.0001% gluten). Commercially available tests for gluten in foods can't reliably detect gluten below around 3 parts per million, so it's impossible to say how much gluten, if any, actually is in these eggs.
But yes, some people are sensitive to gluten at those levels, and they've reported seeing their symptoms resolve when they drop eggs from gluten-fed chickens. They've been able to eat eggs again by sourcing them directly from farmers who don't feed their chickens gluten grains.
I should point out that there's a growing number of small farmers who advertise soy-free eggs for people who are sensitive to soy proteins. It honestly wouldn't surprise me to see gluten-free eggs advertised in the same way over the next few years.