Sulfites, or as they are known in Commonwealth nations, sulphites, are a group of naturally occurring and artificial compounds that either act as natural preservatives in fruit, fruit juices, and wine, or as artificial preservatives added to almost every conceivable kind of mass-produced food product. The most common sulfites in fruit and vegetable juices and other supermarket products are:
- Caustic sulfite caramel, also known as caustic sulphite caramel and E150b, used to add caramel colors to juices and also to whiskey,
- Sulfite ammonia caramel, also known as sulphite ammonia caramel and E150d, used to add caramel color to carbonated beverages and fizzy juice drinks,
- Sodium sulfite, also known as sodium sulphite and E221, the preservative used in home wine making and sometimes added to juices made in large batches,
- Sodium bisulfite, also known as sodium bisulphite, sodium hydrogen sulfite, sodium hydrogen sulphite, and E222, used to keep green vegetables from turning brown in salads and in green vegetable juices
- Sodium metabisulfite, also known as sodium metabisulphite and E224, the preservative used in commercial wine making,
- Potassium metabisulfite, also known as potassium metabisulphite and E224, used to stabilize wine and beer,
- Potassium sulfite, also known as potassium sulphite and E225, used as a juice preservative in Australia and New Zealand but not in the UK,
- Calcium sulfite, also known as calcium sulphite and E 226, used as a preservative in apple cider and apple juice,
- Calcium hydrogen sulfite, also known as calcium hydrogen sulphite and E227,
- Potassium hydrogen sulfite, also known as potassium hydrogen sulphite and E228.
Sulfur dioxide (sulphur dioxide, E220) is not a true sulfite but it also acts as a food preservative and triggers the same kinds of reactions in the human body.
Whether or not these compounds are listed on the label depends on national law. The United States requires sulfites added as preservatives to be declared in the list of ingredients but does not require declaration of naturally occurring sulfites or sulfites that are not added as preservatives (as long as the total concentration does not exceed 10 parts per million). In Australia and New Zealand, sulfites must be declared any time the concentration of added sulfites exceeds 10 parts per billion. In these countries, “sulfites” are considered as a group. In the European Union, the different kinds of sulfites are listed separately by their E numbers.
Sulfites cause two general kinds of health problems. They interact with and destroy vitamin B1 (thiamine). This usually is not a major problem in fruit and vegetable juices because most people have many other food sources for getting their vitamin B1.
A much bigger problem is the tendency to have allergic reactions after consuming juices or other food products that are preserved with sulfites. Strictly speaking, almost no one has an allergy to sulfites. Consuming sulfites increases the risk of allergies to other ingredients in the juice or food, especially any red or yellow dyes, as well as allergies to aspirin and aspirin-like compounds in food. On the other hand, these same sulfites protect against chronic obstructive pulmonary disease, high-altitude respiratory problems, and lung cancer.
If you are allergic to aspirin or if you have a tendency to get hives, avoid products that list sulfites, sulphites, or sulfur dioxide on the label. But if you don't have these problems, enjoy these products in moderation.