Adverse Reactions to Food Additives and Preservatives

Thousands of substances are added to various foods for the purposes of coloring, flavoring, and preserving them. 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

The U.S. Food and Drug Administration (FDA) keeps a list of all of the food additives currently used in the United States. Food additives can be categorized into a handful of 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, nitrites, and acids)

Possible Reactions

Many types of adverse reactions can occur as a result of food additives. Some of them appear to stem from allergies while many others appear to be an intolerance or sensitivity. Reports of reactions to food additives are mainly to do with skin, digestion, and breathing.

• Skin reations: Hives (uticaria), angiodema, atopic dermatitis, sweating, itching, flushing
• Gastrointestinal (digestive) reactions: Abdominal pain, nausea/vomiting, diarrhea
• Respiratory reactions include: Asthma symptoms, cough, rhinitis (stuffy nose), anaphylaxis

Diagnosis

You may suspect a food-additive reaction if you experience symptoms with processed foods and/or restaurant-prepared meals but do not experience them with similar foods prepared from scratch. Various seemingly unrelated foods might, in fact, have common ingredients, such as 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.

In many instances, the only way to truly diagnose an adverse reaction to food additives is to undergo an oral challenge, which involves eating increasing amounts of the suspected problem food while under the close supervision of an allergist.

Problematic Food Additives

Nine particular food additives are the most common causes of allergic or adverse reactions.

Tartrazine

Also known as FD&C Yellow No. 5, tartrazine has been suspected as the cause of many reactions, including 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 tartrazine can cause hives in approximately one in 10,000 people or fewer.

Carmine

Carmine is a red food coloring made from a dried insect called Dactylopius coccus Costa which can be found on a particular type of cactus plant. 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.

Annatto

Annatto is a yellow food coloring made from the seeds of a South American tree, Bixa orellana.

This additive has been found to cause allergic reactions, including anaphylaxis, hives, and angioedema.

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 hives and angioedema.

Emulsifiers and Stabilizers

Emulsifiers: Lecithin is an emulsifier made from soybeans or 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.

Monosodium Glutamate

Monosodium glutamate (MSG) is a flavor enhancer added to various foods, and it 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
• Heart palpitations
• Facial pressure/tightness
• Headaches
• Nausea
• Chest pain
• Drowsiness

MSG is also suspected of worsening asthma symptoms.

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
• Pepper

According to a study published in the Annals of Allergy, Asthma, and Immunology, spice allergies are underdiagnosed.

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
• Hives

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 may increase asthma symptoms in between 3% and 10% of adult asthmatics, particularly those with severe disease. Sulfites can also cause anaphylaxis in a small number of people.

Sulfites cause little to no problems in most people without allergies and asthma, even when large amounts are consumed.

Treatment

Many reactions to food additives 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 always be prepared for a severe reaction, such as by carrying injectable epinephrine and wearing a medical alert bracelet.

The main treatment for people with adverse reactions to food additives is prevention, which means avoiding the culprit additive.