About Sulfites

Sulfites are naturally occurring compounds that have been used for centuries--as far back as the Romans and Greeks. Sulfites have three different functions in modern food processing: prevention of mold, stopping the growth of bacteria and sulfides are also used as a preservative.

Types

Propylene oxide is used in processing grains to prevent mold growth, yet scientific research identifies this as a potential carcinogen. Sodium sulfite is used in meat products to stop the growth of bacteria and calcium sulfite is used as a preservative in wine, juices and canned vegetables. The U. S. Food and Drug administration has banned sulfites on any fruit or vegetable that is commonly eaten uncooked.

Effects

Sulfites are actually antioxidants, and 98% of the American population does not experience any reaction to sulfites. The human enzyme sulfite oxidase breaks down the sulfite in the human body, so a deficiency of this enzyme would allow sulfites to cause a reaction. Sulfites ingested by humans do not accumulate and are quickly excreted from the body. The Food and Drug Administration specialists are not yet certain how the body reacts to the sulfite, even with the presence of the enzyme. Reactions to the sulfites range from nasal congestion, runny nose, sneezing and wheezing to rashes, hives and diarrhea.

Warning

These same sulfites that cause a sensitivity reaction pose an added serious risk for a person allergic to sulfites. Severe throat swelling and severe tongue swelling can obstruct the airway and interfere with breathing. Racing heart, seizures and shock might also develop from the ingestion of sulfites by an allergic person, sometimes in a matter of minutes. For example, hydrogen bisulfite is sometimes used by shrimpers at sea to control melanosis, which is the formation of black spots on the shrimp. The use of the sulfite is not listed on the ingredients or the labeling. This sulfite is usually the cause of a severe reaction to eating shrimp, rather than the shrimp itself. If sulfite additives are used in the winemaking process, this has to be noted on the label. Sulfites occur naturally in grapes and are present in all wines at some level, and can cause these same severe reactions.

Identification

Sulfite sensitivity can begin at any point in life, and scientists do not know the mechanics of the sensitivity or what triggers that sensitivity. Some research has gone toward identifying sulfur dioxide as the culprit. Adverse reactions to drugs by law have to be reported to the FDA, but no such requirement exists for sulfites. Reporting is totally voluntary.

Considerations

Sulfites have a place in a modern lifestyle, but trusting only the label of a product containing sulfites is not always reliable because of inconsistency. A person can home test for sensitivity or allergy by consuming sulfites in very small amounts, gradually increasing the intake while monitoring the results.

Resources

• FDA Guide to foods with sulfites