Why are sulfites used?

Sulfur dioxide(SO2) is a naturally occurring type of sulfite. Mined sulfur is heated into a liquid and used to protect wine from oxidizing. The same method has been used to protect wine from oxidization for centuries. Sulfur dioxide is used to protect the wine's character by inhibiting the growth of molds and bacteria and by stopping oxidation (browning) of the wine. In grape juice or wine, sulfur dioxide reacts with water molecules to form sulfites. A sulfiting agent can be added to foods and beverages in the form of sulfur dioxide (a gas) or as potassium bisulfite or metabisulfite (powders). In solution, all forms act the same way, releasing sulfur dioxide

Is the addition of sulfites to wine a new procedure?

No. There is strong evidence that sulfur dioxide was used by Egyptians and has been in regular use since Roman times. European winemakers have used sulfur dioxide to prevent wine spoilage for centuries.  

Are there also naturally occurring sulfites in wines?

Yes. Wine yeasts naturally produce up to 20 parts per million of SO2 during fermentation. There are also naturally occurring sulfites in other foods. In addition, our own bodies produce about 1,000 mg of sulfites a day through normal biochemical processes.  

When did the Contains Sulfites label become mandatory on wines?

In 1988, a Bureau of Alcohol, Tobacco, and Firearms ruling required all imported and domestic wines, beers and spirits to carry the label if they meet or exceed a threshold 10 parts per million sulfites. Because of naturally occurring sulfites, many wines fall under this ruling, regardless of whether sulfites have been added.

Why the Concern?

The concern over sulfites in the United States arose with the use of extremely high levels of SO2 (1,000 to 3,000 ppm) on salad bars to prevent browning of fruits and head lettuce. This use of sulfites resulted in asthmatic reactions--some serious. In 1986 the FDA banned the use of sulfites on fresh fruits and vegetables while other foods and beverages must now be labeled if they contain sulfites--even those which contain very low levels.

What percentage of the population do sulfites affect?

The reaction is a chemical sensitivity found in an extremely small percentage of the population. The majority of sulfite-sensitive people are asthmatic, but represent less than 3% of the asthmatics.

Red Wine Headache vs. Sulfite allergy

Many people complain of getting headaches after drinking red wines. Although some of these people had one bad experience from drinking lousy wine or simply overindulging and now blame all red wines, there seems to be enough anecdotal evidence to suggest that others experience a real physiological reaction after drinking many red wines. As serious a problem as this is, it is impossible to get government funding to study how those who are sensitive to red wine could more safely enjoy it.

 The Puzzling Red Wine Headache - By Marian Burros

For some people, a glass of red wine is an invitation to a roaring headache. After a few episodes of headache and queasiness, those who suffer them may banish wine from their tables for life. The symptoms are part of a syndrome known as Red Wine Headache, or RWH.

 “The red wine headache is a real if poorly understood phenomenon,” says an article in the June issue of the Harvard Health Letter. That is a masterpiece of understatement. There are many theories about what causes the syndrome, but few facts. Dr. Fred Freitag, associate director of the Diamond Headache Clinic in Chicago, said no one really knows what leads a patient to develop this type of headache.

It may be caused by “compounds found in grape skins. They are either naturally occurring or produced through fermentation,” Dr. Freitag said. He would postulate no further. “It’s not as if there are hundreds of thousands of dollars for funding” studies to determine the cause, Dr. Freitag said. There is actually a stigma to studying the subject. “I’ve entertained the idea of looking for grants to study this and I've been told, ‘Don’t go there, it’s bad P.R.,’” Dr. Freitag said. Bad publicity comes to those who would study drinking? Carry Nation is with us yet.

Sulfites used to take the blame for RWH. About 20 years ago the Food and Drug Administration determined that about 1 percent of the population is allergic to sulfites and required that wines containing certain levels of the compound be labeled “contains sulfites.” Many people have assumed, incorrectly, that the labeling is designed to warn people who get a red wine headache. [In fact, sulfite sensitivity is a true allergy. Sufferers experience an allergic reaction, but not a headache. RWH is something else.]

 Scientists have pointed out, however, that many sweet white wines contain more sulfites than red wines — yet do not cause headaches in those who suffer from RWH Additionally, dried fruits usually contain sulfites but you never hear of dried fruit headaches. Sulfites can cause an allergic reaction [breathing problems], Dr. Freitag said, but they give headaches only to asthmatics.

 Other experts think tannins are at the root of the headaches. Tannins are the flavonoids in wine that set one’s mouth to puckering. The Harvard Health Letter notes several well-controlled experiments showing that tannins cause the release of serotonin, a neurotransmitter. High levels of serotonin can cause headaches and that may happen in people who also suffer from migraine headaches. But that does not explain why people who do not get migraines get RWH. Dr. Marion Nestle, chairwoman of the Department of Nutrition and Food Studies at NYU, added that no one complains about tea, soy, or chocolate headaches — though all contain tannins.

A third school of thought blames histamines. Histamines are 20 - 200% higher in red wine than in white, and those who are allergic to them are deficient in a certain enzyme. Some experts believe that the combination of alcohol and that deficiency can cause the headaches. But a study of 16 people with an intolerance to wine, reported in the Journal of Allergy and Clinical Immunology (Feb 2001) found no difference in reactions to low- and high-histamine wines.

 A fourth suggestion is that prostaglandins — substances that contribute to pain and swelling — may cause RWH.  Yet for most people who suffer from RWH, the hypotheses are irrelevant. They want to know what to do about the problem. Some Web sites suggest prevention: for histamine sensitivity, pop a non-sedating antihistamine like Claritin or take an aspirin to stop production of prostaglandins.

Dr. Freitag frowns on this. To lick the problem, he advises a potentially long, painful, and costly experiment. A sufferer of the headaches himself, Dr. Freitag finds that he can drink some reds and not others. “Try different brands, different grapes, different countries of origin. That’s the only way you are going to find out.” Drink a half a glass of red wine; if it is going to give you a headache, it will do so within 15 minutes. If there is no reaction, stick with that wine for the evening, keeping your alcohol consumption to no more than two glasses. Keep a journal.

 A Possible Solution

 In 1981 Herbert Kaufman, M.D., reported that the prophylactic ingestion of aspirin prevented the red wine headache syndrome, RWH, (Lancet 1981; 1: 1263). He also noted that once RWH begins, aspirin has little or no effect in altering the headache. Five years later, in a non-controlled study, Kaufman reported that aspirin inhibited the immediate and late phases of RWH, and the proposed mechanism was through interruption of prostaglandin synthetase (Immunology and Allergy Practice; 7: 279-84). In a new controlled study, Kaufman and Dwight Starr, M.D., Mt. Zion Hospital and Medical Center, examined, through blind evaluation, various inhibitors of prostaglandin synthetase (IPS) drugs, aspirin, Acetaminophen, and Ibuprophen, to test if the RWH could be prevented by the prophylactic use of these specific medications.

 During the first stage, twelve subjects (nine females and three males) with a history of RWH were challenged with red wine, and all experienced RWH. The subjects returned one week later, stage two, and were given inhibitors of prostaglandin synthetase or placebo one hour prior to wine ingestion. The two who received the placebo were not protected. Kaufman and Starr reported that ten of the subjects who were premedicated failed to develop the RWH; two given Acetaminophen developed a "second phase'' RWH 6-10 hours after wine ingestion.

 Kaufman and Starr conclude that RWH may be due to a metabolic defect and corrected by prostaglandin synthetase inhibitors. Mechanisms of correction remain unclear. Source: H. Kaufman and D. Starr, Prevention of the Red Wine Headache (RWH); A Blind Controlled Study. In New Advances in Headache Research, 2nd edition, ed. F. Clifford Rose. Smith-Gordon, 1991.

 New Information on Headaches, Flushing, and Bloating

 If you suffer from headaches and/or flushed skin when drinking wine, try drinking a cup of black tea before you drink the wine. If you will be drinking over the course of an evening, have another cup or two of black tea during the evening. Quercetin, a bioflavonoid found in black tea, significantly inhibits the headache/flush response (which is an inflammatory effect from histamines), according to Tareq Khan, M.D., a pain expert with St. Luke's Episcopal Hospital in Houston, Texas.

     If the problem you suffer from is bloating dye to alcohol's dehydrating and water retention effects, try munching on magnesium-rich snacks like dark chocolate and unsalted nuts, according to Carolyn Dean, M.D., N.D.

 Who is allergic to sulfites?

The FDA in the US estimates that one in 100 people is sulfite sensitive to some degree, but for the 10% of the population who are asthmatic, up to 5% are at risk of having an adverse reaction to the substance. More importantly, the most significant sulfite sensitivity reactions occur in susceptible asthmatics. From a public health standpoint, the subgroup of greatest concern is the sulfite-sensitive asthmatic population. Of those, the ones in whom the most severe reactions have been reported are steroid-dependent and are taking such drugs as prednisone or methylprednisolone. Most of these individuals have been cautioned by their doctor to avoid sulfite-containing foods or beverages. The number of asthmatic patients that are included in this sulfite sensitive group is estimated to be 500,000 in the United States. The USFDA requires labeling of foods containing 10 ppm or more of sulfites.

 What are the symptoms of a sulfite reaction?

The symptoms of a sulfite sensitivity reaction vary from mild to life-threatening. The most common symptoms are mild and involve a skin rash accompanied by redness, hives, itching, flushing, tingling and swelling. Respiratory symptoms include difficulty breathing, wheezing, and stridor. Gastrointestinal reactions involve nausea and stomach cramps. Much less common but more serious signs and symptoms of sulfite sensitivity are low blood pressure, shock, extreme difficulty breathing, and loss of consciousness. As noted above, these symptoms of a severe reactions are most apt to occur in the steroid-dependent asthmatic person.

 I get headaches, stuffy nose, and rosy cheeks from red wine. Is this an allergic reaction?

Technically, this is not an allergic reaction. What is being described is usually referred to as the “red wine headache syndrome.” This is not related to the sulfite content of the wine but probably due to other substances contained within the wine such as histamines, tyramine, and phenolic flavonoids. Aside from the discomfort of the headache, these symptoms do not appear to be a risk for progression to a more serious reaction. Studies have suggested that these headaches can be avoided or minimized by taking either aspirin, ibuprofen, or acetaminophen prior to drinking wine.

 I can drink only white wines. Do red wines have more sulfites?