What are sulfites?
Sulfites are a class of chemical added to foods to inhibit bacterial growth and discoloration.
It is most commonly used in wine and beer making, and also added to many dried fruits.
- Sodium sulfite
- Sodium bisulfite
- Sodium metabisulfite
- Potassium bisulfite
- Potassium metabisulfite
- Sulfur dioxide
Foods that may contain sulfites (read labels):
- Baked goods using dough conditioners
- Bottled lemon or lime juice
- Canned vegetables
- Dried fish
- Dried fruits
- Grape juice
- Imported candies
- Maraschino cherries
- Potato chips
- Fresh non-organic grapes (can be sprayed in the field or packaged with sulfites during shipping)
- Pickled cocktail onions
- Prepared guacamole
- Prepared mustards
- Prepared potato products (frozen hashbrowns, prepared potato salad, etc.)
- Soup mixes
- Trail mix
- Wine vinegars (red wine, white wine, champagne, or balsamic vinegars)
*Technically, any product that contains over 10 ppm must be labeled, but allergic reactions have been reported at lower concentrations.
*Sulfites are not allowed to be used on fresh produce, like salad bars, because it destroys vitamin B1.
*Sulfites are also not allowed to be used on fresh meat products, because it keeps them red looking for a longer period of time, and can give a false indication of “freshness”
*Technically some sulfites form naturally in wine, so just because the label says no sulfites ADDED does not necessarily mean it is totally sulfite-free. But often the natural levels are low enough to be tolerated by most sulfite-sensitive people. (But note that there are still other components of wine, like phenylethylamine, tannins, or grapes themselves, that could be issues)
- Local anesthetic (lidocaine)
- Some medications
- Some asthma medications
What is the difference between sodium sulfite & sodium metabisulfite?
They are both types of sulfites, but people are more likely to react to sodium metabisulfite than just sodium sulfite.
If someone reacts to JUST sodium metabisulfite & not sodium sulfite, then they may be able the tolerate some amount of sulfites okay, and don’t need to be as restrictive. They can avoid sodium metabisulfite & still consume sodium sulfite, within moderation.
If someone reacts to BOTH sodium metabisulfite AND sodium sulfite, this suggest that they are very sensitive to sulfites across the board, and you probably want to avoid all sources.
Also, if someone is sensitive to sodium metabisulfite, they would likely have issues with potassium metabisulfite as well (2).
According to FDA estimates, 1% of people are sensitive to sulfites. The sensitivity can develop at any time in life.
It is most commonly an issue in people who suffer from asthma. They can develop difficulty breathing when exposed to sulfites.
NOTE: a sulfite sensitivity or allergy is NOT the same thing as a sulfa allergy to certain drugs, and it also does NOT mean that the person will have issues with sulphur (you can’t be allergic to sulfur, since it is the 8th most abundant element in the human body, and exists in all the sulfur containing amino acids).
Eating out tips for people who are sulfite sensitive:
- Avoid anything made with prepared potato products, since they often contain sulfites
- Avoid non-organic grapes
- Avoid dried fruits
- Avoid wine and wine vinegars
- Avoid bottled lemon or lime juices
Nutrients linked to sulfite sensitivities:
- Molybdenum deficiency may be linked to sulfite sensitivity, because molybdenum is a cofactor required in the breakdown of sulfites.
- Copper levels should be checked. Excessive copper may cause a molybdenum deficiency.
- Vitamin B12
- Supplementing with B12 may help reduce adverse reactions to sulfites in those who have asthma. (1000 mcg weekly intramuscular injections were used (for 1 month) in the study (1))
- Sublingual B12 is also an option. It absorbs within 15 minutes, and remains elevated in the blood for at least 24 hours. Daily doses of 2000-4000 mcg may be effective for those with asthma.
Some wines that may be better tolerated by people who are sulfite sensitive: