Photo © Shutterstock
Q: I have been having some odd reactions to some foods and drinks (like
dried fruits, wine, and gluten-free breads) and my husband thinks I might
have a sulfite allergy. He says they’re sprayed on fruits and vegetables.
What can you tell me about this?
A: Sulfites are a group of sulfur-based compounds that occur naturally in
many foods and may be added to some foods and pharmaceuticals as a
preservative. The U.S. Food and Drug Administration (FDA) estimates that one
percent of the population is sensitive to sulfites and says that many of
those people have asthma. Rather than being an allergy, sulfite sensitivity
is a metabolic problem, in the same way that some people can’t digest milk
products because they have a lactase deficiency. In the case of sulfite
sensitivity, there may be a deficiency of an enzyme called sulfite oxidase,
which breaks down sulfites with the help of the trace element molybdenum.
Sulfites are not currently thought to be carcinogenic or mutagenic.
Sensitivity can develop at any age, varies in intensity among different
people, and can occur quite quickly after exposure.
Most reactions are mild, although a minority of sensitive people experience
seriously acute reactions ranging from breathing problems to kidney issues.
Here are some of the main symptoms:
- Digestive distress – from cramps, bloating, and diarrhea to nausea
- Fatigue – from feeling tired after eating to severe muscle fatigue,
exhaustion, and low blood pressure
- Difficulty concentrating (known as “brain fog”)
- Mood swings
- Breathing difficulties, wheezing, and asthma attacks
- Candida fungus infections
- Skin flushing, rashes, hives, and eczema
- Heart palpations and rapid pulse
- Cold and flu symptoms, nasal congestion, runny nose
- Edema, including swelling of the face, lips, mouth, tongue, eyes, and
- The Feingold Association notes that sulfur-based additives have been found
to trigger behavioral reactions in children, including temper tantrums and
What to Avoid
Sulfites are used in the manufacture of many prepared foods, including baked
goods (where it is used as a dough conditioner), crackers, soup mixes, jams
(and anything containing gelatin or pectin jelling agents), soy protein
products like tofu, canned and dehydrated vegetables, sauerkraut, pickles,
relish, gravy mixes, dried fruit, dried herbs, potato chips (and most “junk
food”), trail mix, beer, wine, apple cider, vegetable juices, bottled fruit
juices (most particularly lemon and lime), salad dressings (and anything
else containing wine vinegar), shredded coconut, tea, molasses, processed
cheese foods, fresh or frozen shrimp and lobster, maraschino cherries,
dehydrated or pre-cut potatoes, anything containing beet sugar, and anything
made with high fructose corn syrup, cornstarch, or potato starch/flour.
(Yes, those prepared gluten-free products containing wheat flour
alternatives can be problematic!)
Some foods contain naturally-occurring sulfur and a few very sensitive
individuals might react to them. (The body normally converts sulfur to
sulfites, then sulfates, but that metabolic process doesn’t happen in
sensitive people.) Those foods include garlic, onions, soy, peanuts, maple
syrup, and vegetables like broccoli, cabbage, kale, and asparagus.
Sulfur-based fugicides may also be used during transportation of table
In 1986, in the U.S.A., the FDA banned the use of sulfites on fresh fruits
and vegetables in restaurant salad bars or supermarkets. At that time, the
FDA also required wine, beer, and dried fruit containing sulfites at levels
of 10 parts per million (ppm) or higher to have warning labels.
To aid in your label reading, there are six names used for sulfites: sulfur
dioxide, sodium sulfite, sodium bisulfite, potassium bisulfite, sodium
metabisulfite, and potassium metabisulfite.
However, in many instances, you won’t find any of these on labels because
they are used in the preparation of the basic ingredients (such as flour,
corn starch, etc.) rather than in the manufacture of the final product.
Sulfites can also be used to prevent rust and scale in boiler water that is
used to steam food and even in the production of cellophane for food
packaging. Although they’re not allowed in fresh meat, some absorbent
packaging used to line supermarket styrofoam chicken trays has been found to
contain sulfite preservatives.
The question mentions wine specifically. Because yeast produces sulfites
during fermentation, sulfites are a natural by-product of the wine-making
process. However, most winemakers add an additional small amount of sulfites
as a preservative. Organic wine is not supposed to have added sulfites, but may still show
them on the label due to their natural occurrence.
Sulfites are also in drugs: antiemetics (taken to prevent nausea),
cardiovascular drugs, antibiotics, tranquilizers, intravenous muscle
relaxants, analgesics, anesthetics, steroids, and – ironically – nebulized
bronchodilator solutions that are used by asthmatics.
What To Do
There do not seem to be any tests that will effectively demonstrate a
sulfite sensitivity. The only way to figure it out is to experiment with
what you eat and drink. If you suspect a sulfite sensitivity, remove
anything that might trigger a reaction (see our list of "what to avoid" potential problem
foods above) until you feel normal, then try each food item one at a time to
see if there is a reaction and to discover your personal tolerance level for
certain types of food and drink.
Eating in restaurants can be a problem. You can, however, stick to basic
dishes. For instance, opt for a baked potato over anything that could be
processed. Ask for your salad without dressing. Don’t rely on wait staff to
know whether or not a specific dish contains sulfites – even if they know
what you’re talking about, they won’t necessarily have access to the correct
If you’re purchasing unlabeled foods at a deli or a bulk food store, ask the
store manager to check the ingredient list on the product’s original bulk
packaging. And avoid any nuts, coconut, and dried fruit (see our "what to
avoid" list above), as well as pre-made dips like guacamole.
Other than avoidance, there is no medical cure. However, some people with
sulfite sensitivity find that supplementation with molybdenum (it is in many
multi-vitamin formulations), vitamins B-12, B-6, and B-1, and the coenzyme
tetrahydrofolate to be helpful. Mercury or lead detoxification can help as
Meanwhile you can take heart in knowing that you'll be overall healthier
by avoiding all those supermarket processed foods and cooking from scratch!
Wendy Priesnitz is Natural Life’s editor. She has a sulfite sensitivity.