Flavor enhancers and preservatives, as well as food-coloring dyes, are among the food additives that may elicit allergic reactions in susceptible individuals. Allergic reactions to food additives include hives, diarrhea and other gastrointestinal problems, and respiratory problems such as asthma. According to the Asthma & Allergy Foundation of America, there are eight additives that cause allergic reactions, some more commonly and others rarely.
Monosodium glutamate, or MSG, is added to foods as a flavor enhancer. This common ingredient in Asian foods can result in allergic reactions such as chest tightness and asthma, headache and migraine, diarrhea, sweating and a burning sensation at the nape of the neck and the upper chest.
Countless foods are tinted with yellow dye No. 5 (tartrazine 102 and yellow 2G107) and yellow No. 6 (sunset yellow FCF 110). The yellow dyes contain carcinogenic benzidine and other chemicals that our bodies convert to benzidine. Yellow dye No. 5 can be found in butter and margarine, sodas, medicines, chocolate, candy and oranges. It causes allergy-like hypersensitivity reactions, especially in aspirin-sensitive individuals, and hyperactivity in some children. Yellow dye No. 6 has been reported to cause adrenal and kidney tumors, as well as severe hypersensitivity reactions in some people.
Sulfites are commonly used in the production of processed foods and beverages: wine, dried fruits, white grape juice, frozen potatoes, maraschino cherries, fresh shrimp and certain jams and jellies. In 1986, the FDA banned sulfites from use on fresh fruits and vegetables to retain their color and freshness. Allergic reactions to sulfites usually include itching, skin rash and abdominal discomfort. Some asthma medications even contain sulfites. However, in 5 percent of people with asthma, sulfites can cause anaphylactic symptoms such as chest tightness, hives, stomach cramps, diarrhea and breathing problems. This extreme reaction may be related to a hypersensitivity to inhaled sulfur dioxide.
BHA and BHT
Butylated hydroxy toluene (BHT) and butylated hydroxyanisole (BHA) are added to many breakfast cereals, breads and other grain products to preserve their color, odor and flavor by preventing the oxygen-induced breakdown of the grains. Allergic reactions to BHT and BHA in sensitive individuals include skin swelling, redness, hives and severe itching.
Potassium bromate is used in the preparation of many baked goods. This additive is known to cause cancer in animals, according to the International Agency for Research on Cancer, part of the World Health Organization. After the baking process, a small amount of carcinogenic potassium bromate remains in the bread. Bromate has been banned everywhere except Japan and the United States.
Other additives that may cause allergic reactions are aspartame, nitrates and nitrites, and benzoates. Reactions to these additives are considered rare. In some cases, such as aspartame, the calorie-free sweetener used to sweeten countless foods and beverages, reactions such as hives and swollen eyelids have not been verified. Nitrates and nitrites are used to preserve and enhance flavor and color and to prevent botulism; these additives may cause headaches and hives. Benzoates are preservatives added to cakes, candy, margarine, cereal and salad dressing; reactions to benzoates are rare.