The hidden allergen in your gluten-free foods

Ever hear of lupin? Me neither. That is, until last week, when the Food and Drug Administration (FDA) released a warning about this legume, stating that it can cause allergic reactions ranging from a mild case of hives to full-blown anaphylaxis (yikes). The most susceptible populations: People with existing legume allergies, especially peanut allergies.

The reason this news is troublesome: Lupin is popping up in an increasing amount of foods, thanks to the onslaught of gluten-free products (apparently it makes a great substitute for gluten-containing flours), yet people still have no idea what it is or that it may cause them harm, said Dr. Stefano Luccioli, a senior medical advisor at the FDA.

MORE: 5 Myths About Going Gluten-Free That Really Need To Go Away

So what’s a consumer to do? If you happen to have a peanut allergy, don’t freak out--lupin isn’t problematic for everyone--just consider yourself warned, and be diligent about reading labels. Lupin is required by law to appear on the ingredient list as either “lupin” or “lupine.”

Don’t have an allergy? It’s still good to be aware of what’s in your food, and to know the symptoms of a reaction (hives, swelling of the lips, vomiting, breathing difficulties), since food allergies can develop at any point in your life.

MORE: 10 Gluten-Free Portable Lunches