Adverse Reactions to Food Additives and Preservatives

Food Additives
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There are thousands of substances added to various foods for the purposes of coloring, flavoring, and preserving. Additives are usually only a very small component of foods but a small number of them have been suspected of causing various adverse reactions.

Food Additives

Food additives include the following groups:

  • Food dyes and colorings (such as tartrazine, annatto, and carmine)
  • Antioxidants (such as BHA and BHT)
  • Emulsifiers and stabilizers (such as gums and lecithin)
  • Flavorings and taste enhancers (such as MSG, spices, and sweeteners)
  • Preservatives (such as benzoates, nitrates, and sulfites)

The Food and Drug Administration (FDA) keeps a list of all of the food additives currently used in the United States.

Incidence of Reactions to Food Additives and Preservatives

Since it is probable that many reactions to food additives are not diagnosed, the exact rate of reactions is not known. However, in one population-based study, the incidence was only 0.23 percent.

Reactions That May Occur as a Result of Food Additives

There are many types of adverse reactions that can occur as a result of food additives. Some of these reactions suggest an allergic cause, while many others do not appear to be allergic, but rather an intolerance or sensitivity. Reports of reactions to food additives have included the following:

  • Skin reactions:
  • Gastrointestinal reactions:
    • Abdominal pain
    • Nausea/vomiting
    • Diarrhea
  • Respiratory reactions:
  • Musculoskeletal reactions:
    • Muscle aches
    • Joint aches
    • Fatigue
    • Weakness
  • Neurologic reactions:
    • Behavior and mood changes
    • Attention-deficit/hyperactivity disorder (ADHD)
    • Migraine headaches
    • Numbness
  • Cardiac reactions:
    • Palpitations
    • Arrhythmias

Diagnosing an Allergy to Food Additives

A diagnosis of allergy to food additives is suspected when you experience various reactions to prepared foods or when eating at restaurants, but not from foods prepared at home. Various seemingly unrelated foods might, in fact, have common ingredients, such as food colorings or preservatives.

Once a food or food additive is suspected, allergy testing (using skin testing or RAST) may be possible for certain natural substances such as annatto, carmine, and saffron. Testing for synthetic substances is not possible or reliable, and therefore a trial of a preservative-free diet may support a diagnosis of food additive reactions.

In many instances, the only way to truly diagnose an adverse reaction to food additives is to undergo an oral challenge with the suspected additive under the close supervision of an allergist.

Problematic Food Additives

These are nine of the most commonly problematic food additives that may cause allergic reactions or sensitivities:

1. Tartrazine

Also known as FD&C Yellow No. 5, tartrazine has been suspected as the cause of many reactions, including urticaria (hives), asthma, and other illness. Recent studies have disproven the thought that aspirin-allergic asthmatics were especially sensitive to tartrazine. Other studies suggest a role of tartrazine as worsening atopic dermatitis. The FDA says it can cause hives, but this is very rare and occurs in fewer than one in 10,000 people.

2. Carmine

Carmine is a red food coloring made from a dried insect called Dactylopius coccus costa which can be found on prickly pear cactus plants. This coloring is also found in various cosmetics, drinks, red yogurt, and popsicles. Reactions to carmine include anaphylaxis and occupational asthma and are probably due to allergic antibodies.

3. Annatto

Annatto is a yellow food coloring made from the seeds of a South American tree, Bixia Orellana. This additive has been found to cause allergic reactions, including anaphylaxis and urticaria/angioedema.

4. Antioxidants

Antioxidants such as BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene) are added to prevent the spoilage of fats and oils. Both BHA and BHT are suspected of causing urticaria and angioedema (hives).

5. Emulsifiers and Stabilizers

Emulsifiers: Lecithin is an emulsifier made from soybeans and eggs and may contain soybean proteins. Reactions to soy lecithin are rare, even in soy-allergic people, since the level of this additive is usually very low in most foods.

Gums: Various gums are used as food additives and function as emulsifiers and stabilizers. Major gums include guar, tragacanth, xanthan, carrageenan, acacia (Arabic), and locust bean. Many of these gums are known to worsen asthma, particularly in the occupational setting, when airborne. Others are known to cause allergic reactions when present in foods. Guar gum can cause severe anaphylaxis.

6. Monosodium Glutamate

Monosodium glutamate (MSG) is a flavor enhancer added to various foods, and also occurs naturally. Reactions to MSG have been called the “Chinese Restaurant Syndrome,” and symptoms include numbness on the back of the neck, shoulders and arms, weakness, and palpitations. Other symptoms include facial pressure/tightness, headaches, nausea, chest pain and drowsiness. MSG is also suspected of worsening asthma symptoms.

7. Spices

Spices are the aromatic part of various weeds, flowers, roots, barks, and trees. Because they are derived from plants, spices have the ability to cause allergic reactions, just like pollens, fruits, and vegetables. The most common spices used include chili peppers, celery, caraway, cinnamon, coriander, garlic, mace, onion, paprika, parsley, and pepper. One study suggested that spice allergies are probably underdiagnosed.

8. Aspartame

Aspartame is a sweetener used in many sugar-free foods and drinks. This food additive has been suspected of causing such symptoms as headaches, seizures, and urticaria.

9. Sulfites 

Sulfites or sulfate agents (in the forms of sodium sulfite, sodium bisulfite, sodium metabisulfite, potassium bisulfite, and potassium metabisulfite) are common preservatives used in various foods and medications. Sulfites cause little to no problems in most people without allergies and asthma, even when large amounts are consumed. Experts agree that sulfites may increase asthma symptoms in approximately 3 percent to 10 percent of adult asthmatics, particularly in adults with severe disease. Sulfites can also cause anaphylaxis in a small number of people.

Treatment of Allergy to Food Additives and Preservatives

Many of the reactions to food additives, such as with MSG, are mild and resolve without treatment. More severe reactions, including urticaria, angioedema, worsening asthma, and anaphylaxis may require immediate medical attention. These reactions are treated much the same way as other food allergies. If reactions are severe, it may be necessary for you to be prepared for a severe reaction, such as carrying injectable epinephrine and wearing a medical alert bracelet.

Otherwise, the mainstay of therapy for people with adverse reactions to food additives is avoidance of the culprit food additive.

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