Sulfites in wine - do they really cause headaches
Contains sulfites - this line on every wine label has, over the years, built the belief that it is precisely sulfites that are responsible for the headache after a glass of red. A few glasses are enough and the next day you blame the mysterious sulfites for your discomfort. Except that science says something entirely different, and the whole myth is one of the most enduring misconceptions in the world of wine. What are sulfites for at all, do they really cause headaches and what really lies behind a wine hangover? The truth is more interesting and surprising than it seems, and understanding it lets you stop blaming the wrong culprit. Here is an honest guide to sulfites in wine: what they are for, why red has fewer than white, whether they really cause headaches and what really causes the discomfort after wine.
What sulfites are for at all
Let us start by understanding why sulfites end up in wine at all. Sulfites, that is sulfur compounds, play a key role in wine as a preservative and antioxidant. They protect the wine from oxidation and the unwanted growth of bacteria and wild yeast that could spoil it. Thanks to them, wine keeps its freshness, stability and flavour for longer. Importantly, small amounts of sulfites also form naturally during fermentation, so practically every wine contains them, even one without additives. Winemakers add a little more to protect the wine, but in small, strictly regulated amounts. In other words, sulfites are not a harmful additive for the sake of it, but a necessary tool for protecting the wine. Without them many wines would spoil quickly. Understanding this function is the first step to debunking the myth, because it shows that sulfites are a normal, needed part of winemaking rather than a suspect substance.
Where the myth came from
It is worth understanding where the myth of sulfites as the cause of headaches came from at all. The key is the line on the label: in many countries the law requires wines containing sulfites to be labelled as such, which made sulfites the most visible component of wine. Since it is the only substance singled out on the label, suspicion naturally fell on it when someone looked for the culprit of a headache. Add to this the association with allergies, because a small group of people really are sensitive to sulfites, though it usually manifests as respiratory reactions rather than headaches. These two things, visibility on the label and the existence of a rare sensitivity, combined into a common but mistaken belief. The sulfite myth is an example of how visible information becomes a scapegoat, despite a lack of evidence. Understanding the origin of the myth helps look at it critically and seek the real cause elsewhere.
What science says
Let us get to the heart of it, that is what science says about sulfites and headaches. Although drinking wine really does trigger headaches in some people, there is no evidence that sulfites are the cause. The available research does not suggest that sulfites cause wine headaches, though the subject is still not fully studied. This is a key statement: science does not confirm a link between sulfites and headaches after wine. In other words, blaming sulfites is blaming the wrong suspect. If sulfites really caused headaches, far more people would suffer from them, and the symptoms would also occur after other, far more sulfite-rich products. Yet that does not happen. The scientific evidence consistently moves sulfites away from the role of culprit, directing attention to other components of wine. It is a basic fact worth remembering: sulfites are most likely not responsible for a wine headache.
Red has fewer sulfites than white
Here comes a fact that completely turns the myth on its head. The common belief holds that red wine causes more headaches due to a higher sulfite content - but the truth is exactly the opposite. European regulations allow up to about two hundred and ten parts per million of sulfites in white wine, while red is limited to about a hundred and sixty. In other words, it is white wine that usually has more sulfites than red, not the other way round. It is a crushing argument against the myth: since red wine is more often blamed for headaches, yet has fewer sulfites than white, sulfites cannot be the cause. If they were, white wine would cause more headaches, which does not match experience. This simple fact about the sulfite content of red and white wine debunks the myth in itself. Red and headaches are linked by something other than sulfites.
The real culprits
If not sulfites, then what really causes a wine headache? Science points to several far more likely suspects. First and most important, alcohol itself, which dehydrates and is the main cause of a hangover after any drink. Second, there are many other compounds in wine more likely connected to headaches than sulfites, like histamines and tannins. Histamines, present especially in red wine, can trigger reactions in sensitive people, and tannins are sometimes linked to discomfort. Third, the most recent research from 2024 points to an organic compound called quercetin. Quercetin is a flavonol formed as grapes ripen in the sun, and when ingested it interferes with the body ability to metabolise alcohol, which can lead to a headache. It is a far more convincing lead than sulfites. The real culprits are alcohol, histamines, tannins and quercetin, not the long-blamed sulfite.
Quercetin - the latest lead
It is worth pausing on quercetin, because it is the freshest and most interesting direction of research into the wine headache. According to research from 2024 by scientists at UC Davis, it is precisely quercetin that may be the key culprit. It is an organic compound, a flavonol, that forms naturally as grapes ripen exposed to the sun. When we ingest it, quercetin interferes with the body ability to properly metabolise alcohol, which can lead to a headache. This would explain why some red wines, richer in quercetin thanks to sun-exposed grapes, more often cause discomfort. This lead is far better grounded in science than the sulfite myth and shows that the answer lies in the chemistry of grapes and alcohol metabolism, not in preservatives. Quercetin is a fascinating example of how real science gradually replaces received myths with concrete, testable explanations. Research is still ongoing, but the direction is promising.
Sulfites are everywhere, not only in wine
Another fact that finishes off the myth is the ubiquity of sulfites in food. Contrary to the belief that wine is a sulfite bomb, many other products contain far more of them. Sulfites occur in fizzy drinks, candy, prepared soups, frozen juices, processed meat, crisps, French fries and dried fruit. Surprisingly, dried fruit can contain up to a thousand parts per million of sulfites, while wine usually has around ten. It is a huge difference: a dried apricot can have a hundred times more sulfites than a glass of wine. If sulfites really caused headaches in the amounts found in wine, then a handful of dried fruit would make us suffer far more. Yet no one blames raisins for a headache. This fact shows the absurdity of the myth: we blame wine for a substance that many everyday products contain far more of, while we do not blame them. Sulfites are everywhere, not only in wine.
What about real sulfite sensitivity
For honesty we must add that a rare, real sulfite sensitivity exists, though it affects a small group of people and manifests differently from what the myth claims. Some people, especially asthmatics, are sensitive to sulfites, but it usually manifests as respiratory reactions, like difficulty breathing or wheezing, rather than a headache. It is a real, if rare, medical problem that has nothing to do with the commonly blamed wine headache. If you belong to this small group, your sensitivity is real, but concerns the respiratory system, not the head. For the vast majority of people, sulfites in wine are completely harmless and cause no symptoms. It is important not to confuse rare, respiratory sensitivity with the myth of sulfites as the cause of headaches - these are two entirely different things. Real sensitivity exists, but it does not explain the popular myth of the headache after wine.
The essentials in brief
Let us gather it up. Sulfites are preservatives and antioxidants that protect wine from oxidation and spoiling, and small amounts also form naturally during fermentation. The myth that they cause headaches came from their visibility on the label, but science does not confirm it - there is no evidence that sulfites cause wine headaches. What is more, red wine, most often blamed, has fewer sulfites than white, which debunks the myth in itself. The real culprits are alcohol, histamines, tannins, and according to the latest research especially quercetin, which interferes with alcohol metabolism. Sulfites are everywhere besides - dried fruit has up to a hundred times more than wine. A rare, real sensitivity exists, but it manifests respiratorily, not as a headache. Now you know that sulfites are not responsible for a wine hangover, and you will stop blaming the wrong suspect.
Note every wine in GustoNote - the type, amount and how you felt the next day. Over time you will see for yourself which wines and which amounts suit you best, regardless of the myths about sulfites.