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A couple in a grocery store reading the food label on a food can.
A change to the Whole30 Program Rules:

Added sulfites are no longer excluded

Melissa Urban, August 2024

The Essential WHOLE30

An overview of Whole30 and sulfites

Since 2010, the Whole30 elimination phase has specifically called out added sulfites. If sulfites in any form were listed on the ingredient label, that product was out for your Whole30 elimination. 

In the early days of Whole30, we were of the mindset that if any research or clinical experience (such as that of our medical advisory board) suggested the ingredient was linked to a food sensitivity and/or reaction, we would eliminate that ingredient from the program. Based on the science at the time and the opinions of our medical advisory board, we believed that sulfites posed enough of a health risk (and that enough people were sensitive to their effects) to recommend leaving it out of the Whole30. In my 2012 book It Starts With Food, I summarized our conclusion as follows: “Sulfites can cause significant dermatological, pulmonary, gastrointestinal, and cardiovascular symptoms in sensitive people.”

Over the years, the Whole30 has evolved in how we think about the program, and how we evaluate science, data, and clinical findings. Today, the goal of the Whole30 is to eliminate as few foods as possible while still delivering participants the best results. This philosophy serves to make the Whole30 more accessible by eliminating fewer foods. It has also encouraged us to lean more heavily on peer-reviewed, high-quality research than clinical experience and anecdotal evidence to determine the program rules.

In 2022 and 2023, we reevaluated the current scientific findings on sulfites, sulfite sensitivities, and health, and found a lack of recent, quality research on this topic. This limitation prevents us from determining any meaningful impact of sulfites on the general population. However, we can safely infer that there is insufficient evidence to justify excluding them from the program when consumed in recommended amounts. 

As a result, the Whole30 program rules no longer call out added sulfites in any form as part of Whole30 elimination. 

Here is a summary of that research, our findings, and our conclusions.

Sulfites (sulphites)

Sulfites are a group of sulfur dioxide-releasing chemicals commonly used to preserve food flavor and color, inhibit bacterial growth, and reduce food spoilage. Sulfites are added to many processed foods, including dried fruits and vegetables, seafood, juices, meat products, cereal, and alcoholic and non-alcoholic beverages. Sulfites can also occur naturally as a product of fermentation, as with balsamic vinegar, molasses, wine, and beer. 

Sulfites may appear under a variety of names on an ingredient label, including:

  • Potassium bisulphite
  • Potassium metabisulphite
  • Sodium bisulphite
  • Sodium metabisulphite
  • Sodium sulphite
  • Sulfur dioxide

The United States Food and Drug Administration (FDA) classifies sulfites with a “generally recognized as safe” status and does not include them in the “big 8 allergens.” However, as with other additives and food components, sulfites can cause food intolerance. (Food processors are required to declare the presence of sulfites in foods when the concentration exceeds 10 parts per million or greater.) Symptoms of sulfite sensitivity may include gastrointestinal disturbances, skin rash, headaches, respiratory symptoms, and even anaphylaxis. 

Our 2022 review of the current data did not cite any evidence demonstrating that sulfites are harmful to the health of the general population when consumed in recommended amounts, and no statements were made that indicate sulfites should be completely avoided by individuals who are not hypersensitive.

Sulfites and asthma

Many of the studies we reviewed mentioned that sulfite sensitivity may be more prevalent in those with asthma. Though the asthma prevalence is from the same scant, low-quality research as other studies on sulfites, the cautions around sulfite consumption for asthmatics came up frequently in our review of the research. 

In addition, people with atopy (asthma, eczema, and seasonal allergies) often have similar food triggers. While sulfites may have non-immunological mechanisms that induce an asthma attack, such as inhalation of sulfur dioxide, IgE reactions (rapid immune responses, or true allergies) are also possible. 

Due to the close relationship among atopic conditions and evidence that sulfite can worsen asthma, persons with other atopy—such as eczema, environmental allergies, or IgE-mediated food allergies—may wish to use caution with sulfite consumption during their Whole30 elimination and reintroduction.

Conclusion

There is insufficient evidence to justify eliminating added sulfites during the Whole30. As a result, the Whole30 program rules no longer call out sulfites in any form as part of your Whole30 elimination. (Meaning, you no longer need to avoid added sulfites on the Whole30.)

However, individuals with a known sulfite sensitivity should avoid consuming sulfite-containing foods, and those with atopic conditions or IgE-mediated food allergies may wish to use caution. 

Most processed foods containing added sulfites are already excluded during your Whole30 elimination phase, because they contain other incompatible ingredients. However, if you choose to avoid sulfites on your Whole30 due to a known sensitivity, health condition, or doctor’s recommendations, read your labels thoroughly on products such as:

  • Mustard
  • Balsamic vinegar*
  • Fruit juice (lemon, lime, grape)
  • Dried fruit
  • Mustard (particularly Dijon)
  • Canned fruits and vegetables

*Balsamic vinegar often lists “naturally occurring sulfites” in the ingredient panel, because of the concentration.

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