Sulfer, Sulfa, and Sulfites--What's the Difference?
There are many misunderstandings when it comes to sulfer and its related compounds. Sulfer is an essential element and part of many different amino acids. It's the eighth most common element in the body and no one is allergic to sulfer. Sulfer is a chelating element and helps remove heavy metals from the blood.
Sulfa drugs (sulfanomide) do cause an allergic reaction in about 3.5 percent of the population, usually manifesting as a skin rash. The reaction is caused by the sulfanomide molecule attaching to a protein and forming a new, larger molecule that can trigger an immune response. It's not the sulfer that causes the reaction; rather, it's the new protein that is the allergen.
Since sulfer is not the cause of the allergy, people who suffer from sulfa allergies do not necessarily have problems with other sulfer compounds such as sulfites. Sulfites occur naturally in fermented food and beverages, but are also added to inhibit the growth of microorganisms. Many people blame red wine headaches on sulfites, but it’s a syndrome independent of sulfites. Other foods that contain sulfites are dried fruits, pickles, sauerkraut, olives, some seafood (shrimp, lobster, scallops), jams, jellies, and molasses.