Sulfites are commonly found in wine, dried fruits, and other processed foods. They're mostly of interest to people with allergies because they're associated with food-triggered asthma attacks, although in rare cases sulfites have been associated with other common food allergy symptoms. The FDA estimates that 1% of the general population and 5% of asthmatics are sensitive to sulfites.
What Sulfites Are:
Sulfites are a group of chemical compounds including sulfur and oxygen, such as sodium sulfite, sulfur dioxide, sodium and potassium bisulfite, and sodium and potassium metabisulfite. They are sometimes naturally occurring, but they may also be added to food during the manufacturing process to prevent browning or serve as a preservative.
Symptoms of Sulfite Allergies:
Sulfites are most strongly associated with asthma attacks. Different people have different thresholds of the amount of sulfites needed to trigger an asthma attack, however, which makes this allergy different than many food allergies. Rarely, sulfite allergies can cause symptoms such as hives, angioedema (redness and swelling), or anaphylaxis.
Asthma and Sulfite Allergies:
The vast majority of people with sulfite allergies react with asthma attacks. Just as for anyone else with asthma, you'll need to manage your asthma in partnership with your doctor by coming up with an asthma management plan. This may include a combination of medications and lifestyle changes. Avoiding foods with high concentrations of sulfites, along with avoiding any other asthma triggers you may have, will certainly be among those lifestyle changes.
Medications and Sulfite Allergies:
While sulfites are a potential trigger of asthma attacks, people with sulfite allergies and asthma should know that many asthma medications actually include sulfites as a preservative. Your allergist can help you choose an inhaler or other asthma medication that is sulfite-free. Injectible epinephrine is among the other medications that generally includes sulfites; however, doctors generally agree that the benefits of epinephrine outweigh the risks of a reaction. Your own doctor is the best source of guidance for your situation.
Foods Containing Sulfites:
Foods that contain high concentrations of sulfites include dried fruits, some fruit juices, wine, pickled foods (such as sauerkraut and onions), and molasses. Among the foods usually containing lower concentrations of sulfites are dried potatoes, some corn-based foods, and wine vinegars. You can find a list of sulfite-containing foods here.
Sulfites and Labeling Laws:
The FDA has placed several restrictions on the use and labeling of sulfites. These include:
- Forbidding sulfites from being added to foods intended for raw consumption (such as salad bars)
- Requiring that sulfites in excess of 10 ppm (parts per million) be indicated on food labels, whether those sulfites are naturally occurring or added during manufacturing
- Requiring that sulfites added for purposes such as preserving foods be labeled, regardless of whether they are in concentrations higher than 10 ppm
You'll see the phrase "contains sulfites" on packaged foods with a sulfite content above 10 ppm.
Sulfites and Alcohol:
There's no such thing as a truly sulfite-free wine or beer, since sulfites occur naturally in alcoholic beverages. However, low-sulfite wines (which fall below the 10 ppm threshold) are available, and these may be viable alternatives for you if your doctor has told you that you have some tolerance of sulfites. These are not, however, for asthmatics who are extremely sensitive or those who may be at risk of anaphylactic reactions to sulfites. Some restaurants may, for a corkage fee, allow you to bring in and drink your own wine.
Eating with Sulfite Allergies:
In addition to avoiding sulfites in medications and managing your asthma, you'll need to avoid sulfites in restaurants and in packaged foods.
Avoiding sulfites in packaged foods is fairly simple, thanks to FDA labeling regulations. You and your doctor may find that you're able to eat some foods with relatively low concentrations of sulfites without triggering a reaction; this can be determined through testing in your allergist's office. In addition to looking for the phrase "contains sulfites" on packaged foods, you should learn the names of added sulfites, as they can appear on food labels, and avoid foods that commonly have high concentrations of sulfites. Your doctor will likely give you such a list. The FDA also recalls foods from time to time for undeclared high concentrations of sulfites, so you may want to subscribe to e-mailed allergy recall lists.
Avoiding sulfites in restaurants is trickier, but you can mitigate your risks by following basic principles of eating safely in restaurants with food allergies. Be aware, though, that even in restaurants that have food allergen charts on-hand for menu items, sulfites are less likely to be among the allergens they've prepared for. This means you'll need to be clear with the chef and waitstaff about your allergy. A list of high-sulfite foods that you can give to the chef may be useful in helping to come up with safe dishes. And just in case, make sure that whenever you eat food away from home, you carry your asthma medication and epinephrine (if prescribed).
In addition to avoiding pickled foods, juices that tend to contain sulfites and other foods that are known hazards, you should be aware of some foods that are particularly risky to eat in restaurants. Potato dishes in restaurants are frequently made from dried potatoes treated with sulfites. French fries, hash browns, and similar potato dishes should be considered risky unless you can confirm with the kitchen that they're prepared onsite from fresh potatoes. Also ask about wine or lemon juice (which may be bottled and high in sulfites) in soups, sauces, or rice dishes.
Adkinson, N. Franklin, et al. Middleton's Allergy: Principles and Practice. "Chapter 90: Food and Drug Additives Known or Suspected To Cause Adverse Reactions." 6th ed. Philadelphia: Mosby, Inc., 2003. Papazian, Ruth. "Sulfites: Safe for Most, Dangerous for Some." U.S. Food and Drug Administration. Internet Resource. 17 March 2008.
Adkinson, N. Franklin, et al. Middleton's Allergy: Principles and Practice. "Chapter 90: Food and Drug Additives Known or Suspected To Cause Adverse Reactions." 6th ed. Philadelphia: Mosby, Inc., 2003.
Papazian, Ruth. "Sulfites: Safe for Most, Dangerous for Some." U.S. Food and Drug Administration. Internet Resource. 17 March 2008.