Doctors associate many types of food additives with adverse food reactions. The most frequently implicated food additives are

• Monosodium glutamate (MSG): When consumed in large quantities, this flavor enhancer reportedly causes burning sensations, facial pressure, chest pain, headache, and, in rare cases, severe asthma symptoms. Although many sufferers associate these types of reactions with eating Chinese or other types of Asian foods, no conclusive studies have determined a clear link between consuming MSG and adverse food reactions. In any event, with the recent increase of MSG-free restaurants in many parts of the United States, you should have no trouble finding a place to chow down on chow mein without suffering ill effects.
• Tartrazine (yellow dye No. 5): This and other food dyes can aggravate chronic hives and may actually be an ingredient in the very same children's syrups used to treat allergic symptoms such as hives -- another good reason to always check medication labels.
• Sulfites: Additives, such as sulfites, are often used as antioxidants to preserve wine, dried fruit, shrimp, and potatoes. These additives have been implicated in cases of allergic food hypersensitivities, including potentially life-threatening bronchospasm (constriction of the airways) and asthma symptoms, especially in severe asthmatics who require long-term treatment with oral corticosteroids. Exposure to sulfites, when used in salad bars and in the guacamole served in some restaurants, can trigger asthma symptoms in susceptible asthmatics when they inhale the sulfite fumes from treated foods. These antioxidant additives are sometimes used to prevent discoloration and to keep greens looking perky.