What are Food Additives and Preservatives?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 have been suspected of causing various reactions. 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.
How Common are 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, various studies estimate that the rate is probably less than 1% of adults, and up to 2% of children.
What Reactions Occur as a Result of Food Additives?There are many types of 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. Reports of reactions to food additives have included the following:
- abdominal pain
- asthma symptoms
- muscle aches
- joint aches
- behavior and mood changes
- attention deficit and hyperactivity disorder
- migraine headaches
How is Allergy to Food Additives Diagnosed?A diagnosis of allergy to food additives is suspected when a person experiences 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 to 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 for the person to undergo an oral challenge with the suspected additive under close supervision of an allergist.
Which Food Colorings Cause Reactions?Tartrazine.Also known as FD&C Yellow #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.
Find out how to follow a tartrazine-free diet.
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 are probably due to allergic antibodies.
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.
Saffron.This yellow food coloring, obtained from the flower of the Crocus sativa plant, has been reported as a cause of anaphylaxis.
Many other food colorings are less common, but possible, causes of adverse reactions. These include sunset yellow (yellow #6), amaranth (red #2), erythrosine (red #3), and quinoline yellow, among others.
What about 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.
What about Emulsifiers and Stabilizers?Lecithin. Lecithin in 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, carageenan, acacia (Arabic) and locust bean. Many of these gums are known to worsen to worsen asthma, particularly in the occupational setting, when airborne. Others are known to cause allergic reactions when present in foods.