Are sulfites in food bad for you? A comprehensive health guide.

November 26, 2025 •

4 min read

While sulfites are generally considered safe for the vast majority of people, a small percentage of the population, particularly asthmatics, can experience adverse reactions to them. This guide delves into the specifics to address the question: Are sulfites in food bad for you?

Quick Summary

Sulfites are common food preservatives and also occur naturally in some items. They are safe for most, but can trigger allergy-like symptoms, especially in sensitive people with asthma.

Key Points

Safety for Most: Sulfites are generally safe for the majority of the population and are widely used as food preservatives.
Sulfite Sensitivity: A small portion of people, predominantly asthmatics, can have a sensitivity that triggers allergy-like symptoms, not a true immune allergy.
Common Symptoms: Reactions can include wheezing, hives, and gastrointestinal upset, though severe anaphylaxis is very rare.
Labeling is Key: In the U.S., foods containing 10 ppm or more of sulfites must be declared on the label. Check ingredient lists for various sulfite compounds.
Different Forms: The reactivity of sulfites can differ by food; for instance, the more reactive free sulfites in wine can affect sensitive individuals differently than the bound sulfites in dried fruit.
Sources to Monitor: High-sulfite foods include wine, dried fruits, some processed vegetables, and certain condiments. Limiting processed foods is a good strategy.

What Exactly Are Sulfites?

Sulfites are inorganic salts containing sulfur and have been used as a food preservative since antiquity to inhibit microbial growth, prevent oxidation, and control enzymatic browning. They are found in many forms, such as sulfur dioxide ($SO_2$), sodium sulfite, sodium bisulfite, and potassium metabisulfite. Sulfites occur both naturally, especially during fermentation, and are added by food manufacturers to maintain freshness, color, and texture. Yeast, for example, naturally produces sulfites during the fermentation process for wine.

Are Sulfites Bad for Most People?

For the majority of the population, sulfites are safe to consume in typical quantities and are not a cause for concern. The U.S. Food and Drug Administration (FDA) has classified sulfites as "Generally Recognized as Safe" (GRAS) for most people. Similarly, the European Food Safety Authority (EFSA) and other international committees have concluded that sulfites are safe for most consumers. However, it is important to note that while they don't pose a risk for most, there are no particular health benefits associated with consuming added sulfites.

The Reality of Sulfite Sensitivity

Issues with sulfites arise for a small segment of the population with a sulfite sensitivity or intolerance, not a true allergy involving the immune system for most cases. Sensitivity can develop at any time during a person's life. People with asthma are at the greatest risk, with studies suggesting that 3-10% of asthmatics have a sensitivity to sulfites that can cause respiratory issues. The severity of reactions varies significantly among sensitive individuals, from mild to, in rare cases, life-threatening.

Common symptoms of sulfite sensitivity:

Respiratory: Wheezing, chest tightness, shortness of breath, and coughing.
Dermatological: Hives (urticaria), skin rashes, and flushing.
Gastrointestinal: Abdominal cramps, nausea, vomiting, and diarrhea.
Other: Headaches, dizziness, and difficulty swallowing.

Why does sulfite sensitivity occur?

The exact mechanisms are not fully understood, but several theories exist. These include:

Sulfur dioxide inhalation: When consuming sulfite-containing foods or drinks, the release of $SO_2$ gas can irritate and constrict the airways.
Enzyme deficiency: Some individuals may have low levels of the enzyme sulfite oxidase, which is responsible for breaking down sulfites in the body.
Immune response: While rare, some reactions may be mediated by IgE antibodies, indicating a true allergic response.

Sources of Sulfites in Food and Drink

Many foods contain sulfites, some naturally and others due to intentional addition as a preservative. According to FDA regulations, if a food contains 10 parts per million (ppm) or more of sulfites, it must be declared on the label. Since 1986, the FDA has also prohibited the use of sulfites on fresh produce intended to be served raw, such as in salad bars.

How to read food labels

To identify sulfites, check the ingredient list for terms such as: sulfur dioxide, sodium sulfite, sodium bisulfite, sodium metabisulfite, potassium bisulfite, and potassium metabisulfite. For wines, the label must state “Contains Sulfites” if the concentration exceeds 10 ppm.

Dried Fruit vs. Wine: Sulfite Form Matters

Interestingly, the type and form of sulfite can impact how a person reacts. A common misconception is that if you can eat dried apricots, you won't react to sulfites in wine. However, this is not true due to differences in how the sulfites are processed.

Comparison Table: Sulfites in Wine vs. Dried Fruit


Feature	Dried Fruit (e.g., Apricots)	Wine (White & Rosé)
Sulfite Level (Approx.)	High (often > 100 mg/L)	Moderate to high (up to 200 mg/L)
Primary Form	Mostly bound sulfites	Free sulfites, which are more reactive
Absorption Mechanism	Broken down during digestion	Absorbed more quickly through the mouth and stomach lining
Reactiveness	Less reactive due to binding	More reactive, can trigger immediate symptoms
Impact on Sensitives	May cause reactions, but often milder than wine	More likely to cause adverse effects due to free sulfite content

Tips for Managing Sulfite Sensitivity

For individuals with known sensitivities, the best strategy is avoidance. Carefully read all food and beverage labels. For unlabeled food, ask the server or store manager about ingredients.

Management strategies:

Limit highly processed foods, which are more likely to contain added sulfites.
Choose fresh fruits and vegetables, as sulfites are banned for use on raw produce.
Opt for sulfite-free wines or wines with low levels of added sulfites, though natural sulfites will always be present.
Always carry necessary asthma inhalers or antihistamines if you have a known sensitivity.
Consult with a healthcare provider, allergist, or dietitian to create a personalized management plan and accurately diagnose sensitivity.

Conclusion

So, are sulfites in food bad for you? For the vast majority of healthy people, the answer is no. They are a valuable preservative that helps ensure food safety and quality. However, for a small subset of the population, particularly asthmatics, sulfites can trigger significant and sometimes severe adverse reactions. The key takeaway for sensitive individuals is careful label-reading and awareness of high-sulfite foods, especially since different food types, like wine versus dried fruit, can affect people differently. By being informed, those with sensitivity can successfully navigate their diet and minimize their risk of reactions.

For more detailed information on FDA regulations and analysis methods for sulfites, you can refer to the official Federal Register notice.

Frequently Asked Questions

Sulfites are chemical compounds containing sulfur, used as a food preservative and antioxidant to prevent spoilage, inhibit bacterial growth, and stop foods like dried fruit from browning. They can also occur naturally in fermented products like wine.

For most sensitive individuals, a reaction to sulfites is an intolerance or sensitivity, not a true IgE-mediated allergy involving the immune system. However, allergic-type symptoms can occur, and severe reactions are rare.

Symptoms can range from mild to severe and may include respiratory issues like wheezing and chest tightness, skin reactions such as hives, and gastrointestinal problems like stomach pain and diarrhea.

Common sources include wine, dried fruits (apricots, raisins), processed potatoes, pickled foods, some baked goods, certain beverages, and condiments.

While often blamed, there is limited scientific evidence directly linking sulfites to headaches for most people. Other compounds like histamines and tannins, or dehydration, are more likely culprits for wine-related headaches.

Sensitive individuals may react due to inhaling sulfur dioxide gas released from food, a deficiency in the enzyme that breaks down sulfites, or other poorly understood mechanisms. Those with asthma are particularly susceptible.

Not necessarily. The form of sulfites differs; wine contains more reactive 'free' sulfites that are absorbed differently than the mostly 'bound' sulfites in dried fruit. A sensitive person might react to wine but not dried fruit, or vice versa, depending on their specific sensitivity.

In many regions, foods with 10 ppm or more of sulfites must be listed on the label. Always check the ingredient list for specific sulfite compound names, such as sodium bisulfite or potassium metabisulfite.