How Unhealthy Are Sulfites? Separating Fact from Sensitivity

November 29, 2025 •

3 min read

While sulfites are added to many foods and drinks to prevent spoilage and discoloration, studies show that adverse reactions affect a small percentage of the population. This leads many to question: how unhealthy are sulfites for the average person versus those with sensitivities?

Quick Summary

Sulfites are common food preservatives and naturally occurring compounds that are safe for most but can trigger adverse reactions in sensitive individuals, especially those with asthma. Symptoms range from mild skin rashes and stomach upset to severe breathing issues. Regulatory labeling is in place to help affected consumers.

Key Points

Not Unhealthy for Most: For the vast majority of the population, sulfites are a harmless food additive and naturally occurring compound.
Impacts Sensitive Individuals: Sulfites pose health risks primarily to a small percentage of the population, particularly asthmatics, who can experience respiratory issues.
Sensitivity vs. Allergy: Adverse reactions are most often a sensitivity or intolerance, not a true immune-system allergy.
Wine Headache Myth: Sulfites are not the cause of wine headaches for most people; other compounds like histamines, tannins, or alcohol are more likely culprits.
Read Labels: In many regions, products with more than 10 ppm of sulfites must be labeled, making it easier for sensitive individuals to avoid them.

What Are Sulfites?

Sulfites are inorganic salts based on sulfur dioxide ($SO_2$) that have been used as food additives for centuries. They act primarily as a preservative, preventing oxidation and microbial growth in a wide range of food and beverage products, including wine, dried fruit, and canned vegetables. Sulfites also occur naturally in many fermented products as a byproduct of yeast metabolism. The human body even produces small amounts of sulfites during the metabolism of sulfur-containing amino acids. While they are functional and useful, it is the reactions in sensitive individuals that raise questions about their health effects.

The Difference Between Sensitivity and Allergy

It is important to distinguish between a sulfite sensitivity (intolerance) and a true IgE-mediated allergic reaction. True sulfite allergies are extremely rare, involving an immune system response. Sulfite sensitivity, on the other hand, is a non-allergic reaction that still produces allergy-like symptoms. The vast majority of reported adverse reactions to sulfites fall under this category of sensitivity or intolerance.

The Real Health Risks of Sulfites

For the vast majority of the population, sulfites pose no health risk and are safely metabolized by the body. The primary health concerns are limited to susceptible individuals, predominantly those with asthma. It is estimated that between 5% and 13% of people with asthma may be sensitive to sulfites, with symptoms ranging from mild to life-threatening.

Respiratory Symptoms

For asthmatic individuals, consuming or inhaling sulfites can cause bronchoconstriction, leading to asthma-like symptoms within minutes. This can manifest as:

Wheezing
Tightness of the chest
Coughing
Shortness of breath

Other Adverse Reactions

Though less common, sulfite sensitivity can also cause other reactions that are not respiratory in nature. These can include:

Dermatitis (skin rash), hives (urticaria), or flushing of the skin
Gastrointestinal distress, such as abdominal pain, nausea, and diarrhea
In very rare cases, anaphylaxis—a severe and potentially fatal reaction—can occur.

Sulfites and Wine Headaches: A Common Misconception

One of the most persistent myths about sulfites is that they are the cause of wine headaches. However, scientific evidence does not support this claim. In fact, white wines generally contain more added sulfites than red wines because the tannins in red wine act as natural preservatives. Other substances found in wine, such as histamines, tyramines, and the alcohol itself, are more likely culprits for headaches in sensitive individuals. Dehydration is another major contributor to wine-related headaches.

Navigating Sulfite-Containing Foods and Regulations

For those who suspect a sulfite sensitivity, careful label reading is crucial. The FDA requires any product containing 10 parts per million (ppm) or more of sulfites to declare "Contains Sulfites" on the label.

Common foods and products containing sulfites:

Dried fruits (apricots, raisins)
Wines and some beers
Bottled lemon and lime juice
Vinegar
Pickled foods and sauerkraut
Processed meats like sausages and hot dogs
Dried potato products (e.g., dehydrated potatoes, instant mashed potatoes)
Some condiments, jams, and sauces

Sulfite Levels in Different Foods

It is often surprising to learn just how varied sulfite concentrations can be. The following table provides a general comparison of sulfite levels found in some common products.


Food/Beverage Type	Typical Sulfite Levels (ppm)	Note
Dried Fruits	500-2000+	Higher levels used to prevent browning
White Wine	~250-450	Needs more sulfite due to lack of tannins
Red Wine	~50-350	Tannins provide natural protection, so less is added
Instant Mashed Potatoes	Varies	Preservatives aid in long-term storage
Shrimp (Fresh or Frozen)	Varies	Used to prevent black spots, often at low levels

Diagnosis and Management

If you experience symptoms you believe are linked to sulfite consumption, it is important to consult a doctor or an allergist. They can conduct tests to determine if you have a sensitivity. Management primarily involves avoidance, but understanding your personal threshold is key. For severe sensitivities, carrying an epinephrine auto-injector is recommended.

Conclusion: The Final Verdict on Sulfites

For the average person without an underlying sensitivity, sulfites are not unhealthy. They are a well-regulated food additive that plays a vital role in preserving food quality and shelf life. The primary risk is confined to a specific subset of the population, especially asthmatics, who may experience respiratory and other adverse reactions. Understanding this distinction is crucial. It allows those who are sensitive to take necessary precautions while preventing unnecessary concern for the general public. Instead of fearing sulfites universally, focus on your individual body's reaction and check labels diligently if you have a known sensitivity. You can learn more about food additives and allergies on authoritative sites like Anaphylaxis UK.

Frequently Asked Questions

A sulfite sensitivity is a non-immune response that causes allergy-like symptoms, most common among asthmatics. A true sulfite allergy is a very rare immune system reaction.

Dried fruits generally contain the highest concentrations of sulfites, often far exceeding the levels found in other products like wine.

No, it is a common misconception. Research indicates that other compounds in wine, such as histamines and tannins, or simply dehydration, are more likely to cause headaches than sulfites.

All wines contain some level of naturally occurring sulfites, as they are a byproduct of the fermentation process. However, the term 'contains sulfites' on the label refers to added sulfites.

The most common symptoms include respiratory issues like wheezing, chest tightness, and coughing, especially for those with asthma. Other symptoms can be hives, flushing, and digestive upset.

The best way to avoid sulfites is by carefully reading food labels and checking for 'Contains Sulfites'. You should also be aware of common sulfite sources like dried fruits, wine, and certain processed foods.

Yes, sulfites are sometimes used as a preservative in certain medications, including some topical creams, eye drops, and injectable drugs. Individuals with sensitivities should always inform their doctor.