For some, even a sip or two of wine can make their airways tighten and inflamed – and a common trigger is sulfites, added to wines as a preservative. (Contrary to popular belief, white wines usually have more sulfites than reds.) Even the wines labeled “sulfite-free” usually contain small amounts of the substance because it occurs naturally. A chemical called acetaldehyde has also been blamed for asthma flare-ups from alcohol – and for nasty hangovers.
A small number of people are allergic to pure ethanol, but the bigger culprits behind true allergic responses are base ingredients, including barley, hops, yeast and grapes. Agents that are derived from foods such as egg and seafood are often used to clarify wine, but in such minuscule quantities that many question whether they pose a serious risk. Symptoms of true allergic reactions can include congestion, runny nose, swelling, hives, asthma, and in rare cases, anaphylaxis.
Allergy-like reactions. A person who reacts to alcohol may have classic allergy symptoms, but it may not be a “true” allergy. For example, reactions to sulfites in wine are not considered true allergic responses because the underlying physiological mechanism is different – and yet the sulfite-sensitive may experience asthma and even anaphylaxis. Glycoproteins are suspected of producing either allergy or allergy-like reactions.
Intolerance. Substances commonly found in wine including histamine (more often in reds than whites) can lead to sneezing, flushing, headache, diarrhea, skin itch and shortness of breath. Other amines such as tyramine and tryptamine, may play a role in alcohol intolerance; and salicylate, a chemical found in grapes, yeast, wine, beer and many foods, can lead to hives and eczema.
Asian Flush. Many people of Asian descent experience flushing, rapid heart rate, and reduced blood pressure because of a genetic incapacity to properly metabolizing alcohol. So-called “Asian Flush” is thought to be caused by the deficiency of enzymes called aldehyde dehydrogenases (ALDH).
Migraine. Red and white wines have been implicated in these headaches.
Sources: The Auckland Allergy Clinic and The Australasian Society of Clinical Immunology and Allergy.