Added sulfites are no longer excluded
Melissa Urban, August 2024
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.
Bibliography
- Raatz SK, Conrad Z, Jahns L. Trends in linoleic acid intake in the United States adult population: NHANES 1999-2014. Prostaglandins Leukot Essent Fatty Acids. 2018 Jun;133:23–8.
- Guyenet SJ, Carlson SE. Increase in adipose tissue linoleic acid of US adults in the last half century. Adv Nutr. 2015 Nov 13;6(6):660–4.
- Dayton S, Hashimoto S, Dixon W, Pearce ML. Composition of lipids in human serum and adipose tissue during prolonged feeding of a diet high in unsaturated fat. J Lipid Res. 1966 Jan;7(1):103–11.
- DiNicolantonio JJ, O’Keefe JH. Omega-6 vegetable oils as a driver of coronary heart disease: the oxidized linoleic acid hypothesis. Open Heart. 2018 Sep 26;5(2):e000898.
- Ramsden CE, Hibbeln JR, Majchrzak SF, Davis JM. n-6 fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials. Br J Nutr. 2010 Dec;104(11):1586–600.
- Schoeneck M, Iggman D. The effects of foods on LDL cholesterol levels: A systematic review of the accumulated evidence from systematic reviews and meta-analyses of randomized controlled trials. Nutr Metab Cardiovasc Dis. 2021 May 6;31(5):1325–38.
- Schwingshackl L, Bogensberger B, Benčič A, Knüppel S, Boeing H, Hoffmann G. Effects of oils and solid fats on blood lipids: a systematic review and network meta-analysis. J Lipid Res. 2018 Sep;59(9):1771–82.
- Huth PJ, Fulgoni VL, Larson BT. A systematic review of high-oleic vegetable oil substitutions for other fats and oils on cardiovascular disease risk factors: implications for novel high-oleic soybean oils. Adv Nutr. 2015 Nov 13;6(6):674–93.
- Pourrajab B, Sohouli MH, Amirinejad A, Fatahi S, Găman M-A, Shidfar F. The impact of rice bran oil consumption on the serum lipid profile in adults: a systematic review and meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr. 2022;62(22):6005–15.
- Amiri M, Raeisi-Dehkordi H, Sarrafzadegan N, Forbes SC, Salehi-Abargouei A. The effects of Canola oil on cardiovascular risk factors: A systematic review and meta-analysis with dose-response analysis of controlled clinical trials. Nutr Metab Cardiovasc Dis. 2020 Nov 27;30(12):2133–45.
- Calder PC, Campoy C, Eilander A, Fleith M, Forsyth S, Larsson P-O, et al. A systematic review of the effects of increasing arachidonic acid intake on PUFA status, metabolism and health-related outcomes in humans. Br J Nutr. 2019 Jun;121(11):1201–14.
- Su H, Liu R, Chang M, Huang J, Wang X. Dietary linoleic acid intake and blood inflammatory markers: a systematic review and meta-analysis of randomized controlled trials. Food Funct. 2017 Sep 20;8(9):3091–103.
- Marklund M, Wu JHY, Imamura F, Del Gobbo LC, Fretts A, de Goede J, et al. Biomarkers of Dietary Omega-6 Fatty Acids and Incident Cardiovascular Disease and Mortality. Circulation. 2019 May 21;139(21):2422–36.
- Li J, Guasch-Ferré M, Li Y, Hu FB. Dietary intake and biomarkers of linoleic acid and mortality: systematic review and meta-analysis of prospective cohort studies. Am J Clin Nutr. 2020 Jul 1;112(1):150–67.
- Blanco-Rojo R, Sandoval-Insausti H, López-Garcia E, Graciani A, Ordovás JM, Banegas JR, et al. Consumption of Ultra-Processed Foods and Mortality: A National Prospective Cohort in Spain. Mayo Clin Proc. 2019 Nov;94(11):2178–88.
- Handakas E, Chang K, Khandpur N, Vamos EP, Millett C, Sassi F, et al. Metabolic profiles of ultra-processed food consumption and their role in obesity risk in British children. Clin Nutr. 2022 Nov;41(11):2537–48.
- Khan SU, Lone AN, Khan MS, Virani SS, Blumenthal RS, Nasir K, et al. Effect of omega-3 fatty acids on cardiovascular outcomes: A systematic review and meta-analysis. EClinicalMedicine. 2021 Aug;38:100997.
- 18. Szabo Z, Marosvölgyi T, Szabo E, Koczka V, Verzar Z, Figler M, et al. Effects of Repeated Heating on Fatty Acid Composition of Plant-Based Cooking Oils. Foods. 2022 Jan 12;11(2).