No one post on this blog has generated more comments than “Sulfites, Or Why Do I Have A Headache” — about a third of them interesting and the rest not fit for publication. My original article was inspired by a column in the hardcopy (not available online) of the August, 2006 issue of Wine Enthusiast by winemaker and writer Jeff Morgan, challenging several wine myths.

One of these myths is the often heard “I get a headache from drinking wine; I’m allergic to sulfites.” Jeff asserted that it is far more likely that someone’s headache is caused by drinking too much, rather than by reaction to sulfites. I have a background in biochemistry and metabolism, and have kept up on the scientific literature surrounding this topic — in my post I agreed. I pointed out the toxicity of higher alcohols, the allergenic properties of tannins, and the potential vasoconstrictive effects of biogenic amines found in wines.

The original post continues to garner a fair number of good comments, some of which describe variations on sulfite intolerance: a condition occurring mostly in diagnosed asthmatics which causes bronchospasm when they ingest sulfite-containing foods, that may manifest as gastrointestinal symptoms in a few, and as dermatologic symptoms in even fewer. Exactly one of these sulfite-sensitive commenters related headache as a symptom that might be tangentially related their reaction to sulfite intake.

Among the many comments I have not published there runs a thread of a different sort of sulfite intolerance: an intolerance of having preconceived ideas about the supposed toxicity of sulfites questioned. It is one of the wonders of the internet how a discussion about wine headaches can set some people off on tangents about the evils of the food-industrial complex poisoning consumers, a conspiracy that I must be part of since I’m saying your headache was not caused by sulfites. Yep, I definitely get a whiff of brimstone from this bunch.

This past April, Dr. Vino brought up the sulfite issue on his blog. He noted that “Board-certified allergist… Sumit Bhutani, MD… took issue with… lumping all… symptoms as allergies, whether they are or not, and placing undue causality on the histamines and sulfites in wine.” (emphasis mine)

Dr. Bhutani says that sulfites cause respiratory symptoms in the small portion of the population already sensitive to them. For them, most whom already have asthma, the reactions are often severe forms of bronchospastic symptoms and may include anaphylactic reactions (hence the government warning; you can assess your sensitivity to sulfites by eating five dried apricots, which often have higher levels of sulfites than a glass of wine.) He included a link to another study that tested the theory of low-sulfite and high-sulfite wines in patients with a reported history of asthmatic sulfite reactions. There was no objective drop in the subjects’ breathing test with either wine.

Hmmm… Really. And again — no mention of headache.

Finally I’d like to thank “Lucy” (whose comment on my old blog will not be published) for pointing me to a paper titled “Sulfites: Separating Fact from Fiction.” This paper also discriminates clearly between strong allergic reaction to sulfites and sensitivity or intolerance to sulfites. The authors of this paper describe sensitivity as “a large array of dermatological, pulmonary, gastrointestinal, and cardiovascular symptoms.”

Asthmatics that are steroid-dependent or have a great degree of airway hyperreactivity may be at an increased risk of having a reaction to a sulfite containing food. Varying degrees of bronchospasm, angiodema, urticaria, nausea, abdominal cramping, and diarrhea are commonly reported. Adverse reactions to sulfites in nonasthmatics are extremely rare.

As to how common sulfite sensitivity is in the population, the authors note: “…the Food and Drug Administration (FDA) estimates that one out of a hundred people is sulfite-sensitive, and of that group 5% have asthma. Another source states that 5% of asthmatics are sulfite sensitive, compared to only 1% of the nonasthmatic population, while another source estimates that up to 500,000 (or less than .05% of the population) sulfite-sensitive individuals live in the United States.” There must be a wide range of latitude in the definition of “sensitivity” to account for this wide range in the estimation of occurrence — from 1 in 100 to 1 in 2,000.

“Sulfiting agents are not teratogenic, mutagenic, or carcinogenic… however there is a fraction of the public that is sulfite sensitive and susceptible to a wide range of effects…” The Federation of American Societies for Experimental Biology concluded in 1985 that “…sulfites are safe for most people, but could pose a hazard of unpredictable severity to asthmatics and others who are sensitive to them.” The paper concludes:

Sulfites have been used as a food additive since 1664 and have been approved for use in the United States for more than a century. Due to their history of use, sulfites have been generally regarded as safe, however there is also a small percentage of the population that is suspected of being sensitive to sulfites. This sensitivity can cause a wide range of reactions ranging from mild to severe; therefore the proper precautions should be taken.

Amen. I use sulfites in my winemaking, and I will continue to do so. The labels on our bottles state “CONTAINS SULFITES” in a clearly readable size and typeface. I worry for people who have anaphylactic allergic reactions to sulfites — these people should not drink my wine or any other, even wines labeled as “organic” as these will still contain a potentially dangerous amount of sulfites as a natural product of fermentation.

For those individuals who show a range of non-life-threatening sensitivities to sulfites — which may or may not meet the medical definition of “allergies” — I feel compassion. It sucks that these people can’t enjoy a glass of wine, or many other sulfite-containing foods, without discomfort. I’m sorry that sensitive individuals can’t enjoy my wine. I understand that people may feel frustrated that so many foods contain sulfites. And I understand that because I use sulfites — like most other winemakers — we may be targets for that frustration.

Just don’t tell me that sulfites give you a headache.