After a glass of red wine or handful of dried fruit, do you notice flushing, abdominal pain or airway constriction? If so, you may be dealing with a sulfite allergy, and you’re not alone.
Sulfites are food additives that can trigger allergy symptoms in some people, especially those with asthma. They’re also detrimental to your health for several additional reasons.
Sulfites have been linked to free radical damage in the body, which is why they make the list of potential cancer-causing foods. Plus, they mess with your gut microbiome, causing a range of other health concerns.
So are sulfites bad for you, and should you avoid them? Let’s take a look at them, along with what a sulfite allergy means.
What Is Sulfite?
A sulfite is a chemical food additive that’s commonly used as a preservative. Sulfites are used in foods and beverages to limit bacterial contamination.
Sulfite can be a natural byproduct that occurs during the fermentation process and fights yeast and bacteria. Sulfites occur during the winemaking process naturally, for example, but winemakers and food companies also add them to their products to ensure preservation.
The term sulfites refers to:
- sulfur dioxide gas (with the sulfite formula SO2)
- hydrogen sulfites
- sulfur salts containing potassium, calcium or sodium
These molecules are used in food products, including beer, wine and juices; processed meats; canned goods; and dried fruits. They are also found in cosmetic and industrial products.
On a food ingredient label, look out for sulfite types like sulfur dioxide, potassium bisulfite, potassium metabisulfite, sodium bisulfite, sodium metabisulfite and sodium sulfite. Anyone who has a sulfite sensitivity may experience adverse reactions to a food that include these ingredients.
Sulfite Allergy Symptoms and Causes
Adverse reactions to sulfites can occur when they are ingested in foods and pharmaceutical products. Reports show that sulfite exposure can induce a range of sulfite allergy symptoms, including:
- low blood pressure
- abdominal pain
- asthmatic reactions, like difficulty breathing
Exposures that can cause allergy symptoms include consuming sulfites in foods and drinks, taking pharmaceutical products made with these additives, and exposure through occupational settings.
Here are some facts about sulfite allergy:
- 3 percent to 10 percent of people with asthma have a sulfite sensitivity, with steroid-dependent asthmatics and chronic asthmatic children at the greatest risk.
- A vast majority of sulfite allergy reports describe the additive triggering the constriction of airways in asthmatic people.
- It’s rare for non-asthmatics to have sulfite sensitivity. The Food and Drug Administration reports that only 1 percent of the U.S. population is sensitive to the additive.
It’s not entirely clear why some people are more sensitive to sulfites than others. Reports show that they may cause irritation to the respiratory tract, which is why people with asthma are most commonly affected.
Some studies suggest that they stimulate the parasympathetic system, triggering constriction of the airways.
For people who use skin products containing sulfite, like hand and body creams (sometimes medicated), they may experience chronic skin symptoms, like hives or irritation. Sometimes, people consume or use products containing sulfites without recognizing that this additive is the culprit and explains their allergy-like symptoms.
Why Sulfites Are Added to Foods
Sulfites are added to foods to control microbial growth, prevent browning and limit food spoilage. Winemakers add them to prevent oxidation and support freshness.
In addition to this, sulfites also act as:
- bleaching agents
- dough conditioning agents
- alkalinity preventers
- food processing aids
- color stabilizers
Not only do sulfites in foods serve many purposes, but they are also inexpensive and convenient.
Foods that Contain Them
Sulfites are present in most processed foods. They are used for preservation, preventing bacterial growth, maintaining color and more.
Here are the top foods containing sulfites:
- Dried fruits
- Lemon and lime juices
- Grape juices, including sparkling varieties
- Wine vinegar
- Dried vegetables
- Canned foods
- Pickled vegetables
- Frozen potatoes
- Fruit bars
- Trail mix
- Maple syrup
- Deli meats and sausages
- Packaged fish, such as shrimp
- Bottled soft drinks
- Baked goods
- Jams and jellies
- Pizza dough
- Pie crust
- Biscuits and breads
- Potato chips and crackers
Medications that Contain Them
Sulfites are used in a range of pharmaceutical products, including:
- Topical medications
- Eye drops
- Injectable epinephrine (EpiPen)
- Some inhaler solutions
- Intravenous medications, including local anesthetics, corticosteroids, dopamine, adrenaline and phenylephrine
While sulfites are used in EpiPens to prevent browning, they are not known to cause adverse reactions and should still be used when someone is having an allergic emergency.
In addition to these medications, sulfites are also added to cosmetic products, including hair dyes, body creams and perfumes. They are used in the photography and textile industries as well, causing occupational exposures.
Risks and Side Effects
Sulfites in foods and drugs are regarded as safe for consumption by governmental regulatory agencies at concentrations up to 5,000 parts per million.
What does the research say about sulfite side effects? Since the preservatives were declared “generally recognized as safe” for consumption, several reviews have shown that it can actually be dangerous to humans when ingested at even low levels, well under the regulatory recommendations.
Research published in PLoS One in 2017 points out that, “Due to insufficient statistical data regarding individual sensitivities and consumer intake levels, it has been difficult to identify the exact level at which these preservatives become harmful.”
In addition to this, most people consume relatively high amounts of sulfites from the foods and beverages they consume. This is especially true for people eating a typical Western diet of processed foods, canned foods and alcoholic beverages.
What are the dangers of consuming sulfites? Studies are indicating that they can have a substantial impact on gut bacteria.
It makes sense — sulfites are added to foods to fight bacterial overgrowth, so when these foods are consumed and processed in the small and large intestines, they continue their antibacterial effects. This impacts the good bacteria in your gut, too, and alters your microbiome.
Do sulfites cause cancer? According to an evaluation by the International Agency for Research on Cancer, there is inadequate evidence of sulfite carcinogenicity.
Food additives including sulfites, nitrates, food dyes and MSG have been linked to free radical damage within the body. For that reason, limiting your consumption of processed foods containing additives is important for your overall health.
There have been reports of lung cancer among workers exposure to sulfur dioxide as well.
How to Remove Them
You won’t find sulfites in fresh, raw fruits and vegetables or any whole, unprocessed foods. For wine, there are “sulfite-free” options on the market, which means that there’s less than 10 mg/L of sulfites present.
When it comes to sulfites in wine, there’s actually a method to remove the preservatives, at least in theory. Apparently adding a few drops of hydrogen peroxide to your bottle of wine can eliminate the sulfites.
There are products, containing hydrogen peroxide and water, that are meant to remove sulfites when added to your wine. Although these product labels suggest only adding a few drops of the H2O2 solution, it’s important to keep in mind that consuming high concentrations of hydrogen peroxide can be poisonous, as shown my scientific research.
It’s not recommended to consume it unless under the care of a doctor. So adding it to wine? Not an ideal solution to sulfite sensitivity.
For people who experience allergy symptoms to sulfites, avoiding foods containing the additive is the safest and most effective way to avoid adverse reactions.
- A sulfite is a chemical food additive that’s commonly used as a preservative to prevent bacterial growth. This additive is also used to prevent browning, food spoilage and more.
- Sulfites allergy is possible, especially among people who already suffer from asthma. It can cause respiratory, skin and digestive issues.
- Foods without sulfites include fresh fruits and vegetables and whole foods in their natural forms. Processed foods often contain at least low levels of sulfites or other additives.
- Stick to sulfite-safe foods that aren’t processed — not only is it better for those with a sulfite allergy, but it’s also better for your overall health.