At least once a week, someone comes into the shop asking for sulfite-free wine because, he or she says, sulfites give him or her headaches. Because we are asked so frequently, we have done some modest investigation into the possible causes of wine headaches.
Sulfites are often added to wine to neutralize the bacteria that, over time, can produce chemical reactions that result in unpleasant aromas and flavors. While data do not support a causal link between sulfites and headaches, some asthmatics are hyper-sensitive to them, leading the Food and Drug Administration to require labeling—“contains sulfites,” for wines with sulfite levels above 10 parts per million (ppm).
Often people tell us that they are able to drink more wine while on holiday, yet experience no negative physical reaction. Europe does not require the sulfite warning, so absent the warning, people assume that wines sent to America are sulfited and therefore contain higher levels that merit a warning. When we visit producers abroad, we have asked if there is any difference between the wine they sell locally and that which ships to the US. Uniformly, the response is no.
Yeasts naturally produce sulfur dioxide during their chemical interactions with other compounds, so products made with yeast or that go through fermentation, like the lactic acid fermentation associated with pickling, contain sulfites. Beer, bread, cheese, cured meats, dried fruits (think apricots or raisins), molasses, and pickles, among others, all contain sulfites.
These compounds cause blood vessels to dilate, which often manifests as redness in the face, inflammation and can contribute to headaches. Those who have a sensitivity to histamines lack an enzyme in their intestines that helps metabolize it. Histamines are found in the skins of grapes and, since red wines spend more time in contact with their skins, they are in higher concentration in red wines. Other foods high in histamines that may induce a similar reaction include other fermented beverages and foods, aged cheese, cured meats, nuts, certain vegetables like avocados, eggplant and tomatoes, and vinegar-containing foods like pickles and olives.
Another headache-inducing substance naturally occurring in some foods and produced in others via fermentation, aging or spoilage is tyramine. Tyramines first constrict, then dilate blood vessels, the sequence associated with migraines.
There is an enzyme in the liver and the brain, Monoamine oxidase (MAO), that metabolizes tyramine. When that enzyme is inhibited, then tyramines can build up to levels that produce headaches and increase blood pressure. Tyramine is especially concentrated in foods that are preserved, fermented or aged for a long time.
Interestingly, tyramine concentrations vary by varietal, region, and age of the wine. Chianti and Riesling, for instance, are higher in tyramines than are Chardonnay and Sauvignon Blanc. Bordeaux and the Northwest wines measure lower than, for instance, wines from the South of France. This variation may be due to the ambient yeasts that affect the amount of protein produced. Finally, tyramines are higher in young, unfiltered wines.
The bottom line is that wine can set off headaches in some people, but not because of sulfites.