I am certain many of you have heard the statement, "I can't drink wine because I get headaches from sulfites", or "I can drink white wine but not red because I am allergic to sulfites". It is an interesting and debatable subject, but to be quite honest, I am not convinced that sulfites are completely to blame.
On the contrary, I empathize with folks that suffer from some sort of reaction from drinking wine. I, myself do not experience allergic reactions, nor suffer illness or headaches while consuming red (or white) wine. However, the subject intrigues me none-the-less. Herein I will describe the facts and misconception about sulfites, which will hopefully educate and entertain you along the way.
What are Sulfites?
Sulfites (also called sulphite or sulfur dioxide) by definition are compounds that contain the sulfite ion SO32−. We use these compounds to preserve food like dried fruits, dried potato products and wine. The interesting fact is that all wines contain sulfites, because yeast naturally produces sulfite compounds during the fermentation process, and without sulfites, wine would spoil and oxidize. An interesting fact is that white wine has more sulfites than red wines, and dried fruit and processed products have considerably more sulfites than red wine. Additionally, according to the Food and Drug Administration, only 4% of the population is allergic to sulfites, and Dr. Vincent Marinkovich, an allergist and clinical immunologist who has performed extensive research on the subject claims that sulfites pose no danger to about 99.75% of the population.
Foods that Contain Sulfites
Many foods carry high levels of sulfites (More, 2007). Very high levels of sulfites include foods like wine, dried fruits, grape juices, cocktail onions and molasses. Moderate to high-level foods include foods like vinegar, gravies & sauces, fruit toppings and dried potatoes. Moderate level foods include things like shrimp, corn syrup, mushrooms, cordials, avocados, imported sausages and meats, maple syrup, pickles, cheese, clam chowder, ciders, fruit juices and soft drinks. Many products that we consume throughout the day contain high to moderate levels of sulfites and interestingly enough, we even add sulfites to some medications for their antioxidant properties as well as to prevent browning.
Now if you take another good look at the above food list, can you identify how many times you have experienced illness after eating foods from this list (excluding wine)? If you experienced illness, was your first reaction to blame it on sulfites? The answer is probably not. If you still doubt this analogy, try eating a sizable portion of dried fruit. Try apricots, which contain high levels of sulfites. If you do not experience problems after eating the fruit, more than likely, you do not have allergic reactions to sulfites. If you experience reactions while drinking red wine, some other culprit is causing the reaction.
Myths
Andrew Waterhouse, Professor of Enology and Interim Chair, Department of Viticulture and Enology at the University of California, Davis (Waterhouse, 2007) points out factual data regarding sulfites. As aforementioned, "...all wines contain sulfites. Yeast naturally produces sulfites during fermentation so there is only a rare wine which contains none". Second, you may have heard the rumor that wines made outside of the U.S. consist of little or no sulfites. This statement is simply untrue. I have listened to friends and read reports where they talk about drinking wine in France and Italy and rarely feel the [ailing] effects, whereas they drink wine in the U.S. and all hell breaks loose with their olfactory senses and other surfacing symptoms (e.g. headaches and nausea). According to Waterhouse, only the U.S. requires a "sulfite" warning label but 99% of all winemakers in all countries including France, Italy, Spain, Austria, Chile, etc. add sulfites to the wine process. Survey studies conclude that European wines contain an equal amount of sulfites to U.S. wines, which average 80 mg per litter.
Red Wine Composition
"There is something in red wine that causes headaches", says Waterhouse, "but the cause has not yet been discovered". So if its not sulfites causing the allergic reactions, what is it? Well, seeing that wine consists of a plethora of components, its hard to pinpoint which component is the culprit. Wine composition consists of many minor components, as identified below (Waterhouse, UC Davis, 2007). Three of the most prominent are Glycerol (yeast fermentation), Acid (fruit acids that are organic to the grape) and Phenols (responsible for wine color, bitterness, astringency and some odors and flavors).
Culprits
Tannin, on one hand, is a chemical substance, otherwise known as phenolic compounds (referenced as Phenols from the above graphic), which are derived from dark grape skins, seeds and stems as well as oak barrels that gives the wine its color, flavor and structure. Wines with evident tannins will produce a dry, puckery taste sensation, and we refer to these wines as being "tannic". Tannins are our friends, for they prevent oxidation and are in part responsible for a red wine's aging potential. Wines that are particularly high in tannins include Bordeaux, Barolo, Barbaresco, Cabernet & Syrah (Shiraz) varietals. Some of the less tannic wines include varietals like French Burgundy, Dolcetto, Barbera, Pinot Noir, Beaujolais and Tempranillo.
Some experiments suggest that tannins cause a release of serotonin, which can cause headaches for people that typically suffer migraines. If you are one of those people that don't suffer from migraines, but still suffer illness from drinking red wine, this experiment is unfounded, for tannins are also found in foods like tea, chocolate and soy, yet people do not complain about headaches when consuming the later.
Then we have Histamines (An amino-based compound), which are abundant in many food products, and wine is no exception. However, the level histamines in grape skins are not high enough to cause problems for most.
Subsequently, we have alcoholic impurities such as "Cogeners", which are organic molecules that develop during fermentation. Wines with higher concentrations of Cogeners are more prone to cause illness and an interesting fact is that lower quality wines will typically have higher levels of Cogeners. Premium wines are much less likely to have impurities in their final product, so avoid low quality wines at all costs. On the other hand, many will argue that Cogeners are not to blame; a compound named acetaldehyde more likely causes it. This compound naturally converts into acetic acid and if you are one of those people that experience hangovers, your body might have difficulties converting acetaldehyde into acetic acid.
Now we move on to Tyramines, another amino-based compound. This agent occurs naturally during the fermentation process and is a compound found not only in wine, but also in alcoholic beverages, food, beer and ale. Food high in Tyramines include aged cheeses, grapes, figs, pineapple, plums, dried fruits, avocados, shrimp sauces, processed & cured meats (e.g. prosciutto, salami and pastrami), soy & teriyaki sauces, nuts, and chocolate, just to name a few.
As you read the above list, do you see an interesting pattern forming? What intrigues me is that I could not help but notice that many of these food items are something you might find on a hors d'oeuvres platter at any social function. Can we assume that indulging too many Tyramines in one sitting may cause illness? It may be a far stretch, but none-the-less something to consider, but my intuition tells me that its not the wine to blame, but rather, a combination of wine and foods rich in Tyramines that might cause repercussions for some.
Conclusion
We can conclude that we use sulfites for many purposes; not only is it a naturally occurring process in the wine making process, but it is a preservative found in many foods. Based on facts, sulfites are one of many components in wine, and it is inappropriate to attribute sulfites as the solitary component that causes illness. Simply stated, we should not blame sulfites as the lone culprit. Tannins, Histamines, Cogeners and Tyramines also play a part in sensibilities.
There are, however, a few small recommendations that I would propose in order reduce (or eliminate) the aftereffects that some incur. My first suggestion is to opt for premium wine selections. These wines are much less likely to have impurities in their final product, so you will do your self a favor by avoiding substandard products. If you are looking for a sampling of suggestions, check out Enobytes recommendations located at http://www.enobytes.org/wine_reviews.php. We have many good suggestions at a reasonable price point.
Second, when drinking wine, reduce your intake of foods high in Tyramines. Additionally, drink less tannic wines, which include varietals like French Burgundy, Dolcetto, Barbera, Pinot Noir, Beaujolais and Tempranillo. It is also important to drink a lot of water while consuming alcohol, and above all, drink in moderation.
As always, I would love to hear your comments on the subject, regardless if you agree or disagree with my commentary, so please respond on my blog located at http://enobytes.org/blog/index.php?blog=6 or send me an email at pamela@enobytes.org.
References:
More, Daniel, M.D. (2007, April 28). Sulfite Allergy, About.com. [Online]. Available: http://allergies.about.com/od/foodallergies/a/sulfites.htm [2007, May 4].
Waterhouse, Andrew L. (2007, March). Sulfites in Wine, Department of Viticulture and Enology, University of California, Davis. [Online]. Available: http://waterhouse.ucdavis.edu/winecomp/so2.htm [2007, May 4]
