Additives are used in food processing for a variety of reasons: to maintain product consistency, to improve or preserve the nutrient value, to maintain the wholesomeness of foods, or to improve the appearance of foods by providing color and enhancing flavor. Many of these, including food dyes, have been known to cause allergic reactions.
Types of Food Dyes
There are two different types of food dyes according to The US Food and Drug Administration (FDA):
A) Certifiable Color Additives: These food dyes are obtained from petroleum distillates or coal tars. They are synthetic chemicals and are created in a lab. These are what we would commonly call "artificial" colors.
B) Exempt Color Additives: These are commonly referred to as “natural" additives. They are obtained from plants, animals or mineral sources. Because of their “natural" origin we tend to forget that they may be as dangerous as any synthetic food-coloring agent.
Symptoms of a food dye allergies do not differ greatly from symptoms of allergic reactions to other causes. Typical reactions to food dye allergies include: skin problems (urticaria, flushing), respiratory problems (asthma, rhinitis, coughing), gastrointestinal issues (abdominal pain, bloating, gas, nauseas, vomiting), and many other reactions (joint aches, palpitations, headaches, etc).
Examples of Food Dye Allergies
Allergic reactions to food additives are not frequently reported except in extreme cases such as when anaphylaxis life-threatening events occur. For example, in a case report (published in the journal Annals of Allergy Asthma and Immunology 1997;79:415-9.), a 27 year-old female had anaphylaxis that required emergency treatment following ingestion of a popsicle colored with carmine. This was not the first time reports were made about allergies to this food dye. In fact, the same study relates about 3 previously described cases of anaphylaxis associated with carmine. Carmine is a natural coloring agent (obtained from certain bugs) that is not required to be reported on labels because of its natural origin.
Carmine is not the only food dye involved in allergic reactions. Synthetic food colorings are more frequently being pinpointed as the source of allergies and food intolerances. FD&C Red Dye #40, also commonly called Red 40, is used in many of the foods that we consume including bakery, candies, cereals, dairy, drinks, and sauces. It is a synthetic dye, meaning not natural. Chemically speaking, it is an “azo" derived dye. Red 40 has been implicated in many allergic reactions as well as other food-coloring agents that have similar chemical structures such as Sudan 1 and Yellow #6.
Yellow Dye #5, (Tatrazine) has been demonstrated to provoke an allergic reaction in some people and there is specific FDA regulations that requires all prescription medications to post a notice if they are formulated with Yellow 5.