Sulfites in Wine

Sulfites, which are various forms of sulfurous acid, have been used since the days of the ancient Romans and Egyptians for cleansing wine containers. Sulfites were approved for use in the United States in the early 1800s to preserve foods. The antioxidant and antimicrobial properties of sulfites have been most valuable to winemakers. Sulfites either inhibit or kill bacteria and wild yeast encouraging rapid and clean fermentation of wine grapes. Sulfites are also a natural and minor byproduct of yeast fermentation and are produced in tiny amounts during the wine fermentation process. They are added to bottled wine as a preservative.

It is commonly thought that sulfites trigger allergic reactions including asthma in wine drinkers. In the United States, wines must be labeled as “contains sulfites.” As a result, many people blame sulfites when they have a bad reaction to wine. It is possible that some people do have a real allergic response to sulfites (ie steroiddependent asthmatics), but Dr. Pamela Ewan, one of the UK’s leading experts on food allergies, states that “The sensitivity to wine is thought to be due to the direct effect of various - poorly defined - chemical components of wine.” Histamine, which is released into the bloodstream in a true allergic reaction, and is present in small amounts in red wine and much less amounts in white wine, may be one of the culprits. Patients intolerant to wine may not be able to degrade histamine due to a deficiency of the enzyme diamine oxidase.

The headaches, stuffy nose and rosy cheeks that some people develop after drinking red wine is not related to the sulfite content of wine, but probably due to other substances contained within wine such as histamine, tyramine and phenolic flavonoids. These symptoms do not progress to a more serious reaction. Ingesting ibuprofen or acetaminophen prior to drinking can block the “red wine headache syndrome” in some people.

85% of the Chinese and Japanese population have a deficiency of aldehyde dehydrogenase (ALDH). Alcohol is broken down in the liver by two competing enzymes: alcohol dehydrogenase degrades alcohol to the toxic acetaldehyde and aldehyde dehydrogenase converts alcohol to the harmless acetic acid. High levels of acetaldehyde in people with ALDH deficiency cause an unpleasant flushing response and headaches.