E220 (sulfur dioxide)

E220 is sulfur dioxide, a gaseous sulfur compound used in food technology as a preservative and antioxidant. Its role is to limit microbial spoilage, slow oxidation, and help preserve the color of some foods. It is most often discussed in relation to wine, dried fruit, grape and fruit preparations, juices, marinades, and certain long shelf-life products. It is not a nutrient and not a useful dietary source of sulfur; it is a technological tool.

How sulfur dioxide works

Sulfur dioxide and sulfites E221-E228 are connected: in foods they may shift between related forms that create the broader sulfite effect. E220 is important because it can inhibit microorganisms and oxidative reactions. In winemaking, for example, it helps protect flavor and color, while in dried fruit it helps preserve a lighter appearance and reduce spoilage. This is why a food containing E220 may look more stable and brighter than a completely untreated version.

That stability is not the same as nutritional value. Light-colored dried apricots treated with sulfur dioxide may look more attractive than dark untreated apricots, but for low-carb eating dried fruit remains a concentrated sugar source. Wine containing sulfites may be dry and low in carbohydrates, yet alcohol, individual tolerance, and the number of glasses matter more than one label code.

Where E220 matters for keto and LCHF

In keto and LCHF eating, E220 usually appears not as a carbohydrate issue but as a marker of certain product categories. Dry wine may contain sulfites and still contain very little sugar. Dried fruit, in contrast, may be treated with sulfur dioxide but remains high in carbohydrates because of natural sugars. Fruit juices, syrups, and sweet preserves should also be judged first by sugar content and only then by the preservative.

The practical message is that neither “E220 means forbidden” nor “E220 means keto” is a useful rule. The food itself matters. For dry wine, sugar, alcohol, portion size, and body response are decisive. For dried fruit, sugar concentration and ease of overeating matter. For marinades and sauces, sugar, starch, syrups, acids, salt, and spices should be considered together.

Sulfite sensitivity

The main caution around E220 is individual sulfite sensitivity. In some people, sulfite-containing foods may trigger wheezing, stuffiness, coughing, headache, skin reactions, flushing, nausea, or irritation of mucous membranes. People with asthma and reactive airways are often advised to pay particular attention. Such reactions are not universal, but for a sensitive person they can be very practical.

If symptoms repeat after wine, dried fruit, or foods labeled as containing sulfites, it is useful to track the specific foods, portions, and circumstances. Alcohol itself may dilate blood vessels, worsen sleep, and amplify responses to histamine or other compounds. Therefore wine should be assessed not only through E220 but also through alcohol, biogenic amines, amount consumed, food eaten with it, and overall condition.

Practical conclusion

EFSA has considered sulfur dioxide and sulfites as a group of food additives and has emphasized the importance of exposure assessment in people who frequently consume foods containing them. For everyday eating, the conclusion is simple: E220 should not be feared mechanically, but it should not be ignored when repeat reactions occur. In sugar-rich foods it does not make them low-carb, and in dry wine it does not remove the questions of alcohol and tolerance.

The calmest approach is to keep the base of the diet simple and fresh, while treating products with E220 as specific cases. Occasional dry wine that is well tolerated and does not disturb sleep is judged differently from daily dried fruit or sweet fruit preserves. If asthma, strong sensitivity, headaches after wine, or reactions to dried fruit are present, sulfite-containing foods are better limited and symptoms should be discussed with a clinician.