Q: What are sulphites and are they dangerous?
A: An increasing number of wine drinkers complain that drinking wine, even in small amounts, gives them a headache. Many of them believe these headaches are caused by sulphites in wine.
Sulphur dioxide and other sulphites (E220-E228) are preservatives used in a wide variety of foods and drinks, including dried fruits, burgers, sausages, soft drinks, beer - and wine.
All wine contains a small amount of sulphur dioxide, as it is a by-product of fermentation. But, for centuries, producers have added it to wine, to prevent refermentation and oxidation, and to kill off unwanted bacteria. These days, the amount added is very small compared to the 1970s and 1980s. Some natural wine producers do not add sulphur or add very small amounts, which can be risky.
A small percentage of the population, including some asthmatics, can have a serious, life-threatening reaction to sulphites. A larger section report headaches after drinking as little as one glass of wine, usually red wine. This is unlikely to be caused by sulphites, as many foods such as dried fruit, fruit juices, soy sauce, pickles, and conserves often have far higher levels and do not have a similar effect. As sweet wine usually contains the most sulphur, followed by white wine, with red wines the least, it seems unlikely that sulphur is the culprit.
Some scientists believe that histamines may be the problem. Histamines are compounds found in grape skins. As red wines spend much more time in contact with their skins, they contain more histamines. Might they be the baddie and not sulphur? The other possibility is tannins and phenolic compounds, again present in far higher quantity in red wine.
If you do enjoy a glass of wine but suffer from headaches, you might try drinking white wine instead of red, or experimenting with different red wines; some have far lower levels of tannin and histamine.
At the moment, under EU law, wines with levels of sulphur greater than 10 ppm must state it on the label. In effect, this includes virtually every wine.