What could be worse for a company than for its main product to suddenly start making people sick for no discernible reason?

More people are becoming more allergic to more things, and that includes food allergies. Food Business, a trade publication, reports that although the causes are not known, several theories are based on a single irony: In industrialized countries, so many diseases have been eradicated that our immune systems are left “looking for something to do.”

This is the “hygiene hypothesis.”

There are other theories as well. But whatever the cause or causes, allergies to nuts, wheat, dairy products and many other foods are on the rise.

All food producers can potentially be hurt, but restaurants are particularly vulnerable because people with allergies tend to avoid eating out. It’s easy to read an ingredient list in a store; much harder to determine every ingredient in a restaurant meal.

But there are also opportunities. More companies are offering allergen-free foods – an area that Food Business reports is “growing exponentially.”

And the market for allergen-free foods is bigger than the estimated 12 million Americans who have food allergies. Often, those peoples’ families also change their eating habits to accommodate them.