More and more natural and artificial chemicals are being added to our food as preservatives, flavor enhancers, and coloring agents. The U.S. Food and Drug Administration (FDA) lists close to 4,000 substances as food additives.
Despite widespread use of these chemicals in food, adverse reactions are fortunately uncommon. Most cases are described in the literature as single case reports or reports of a small cluster of patients.
Sulfites: These chemicals in the gaseous form can cause lung irritation and may trigger asthma in sensitive asthmatics. They are commonly found in liquid form in processed cold drinks and fruit juice concentrates in order to extend their shelf lives. Sulfites are also added to most wines and sprayed onto cut foods in order to keep them fresh and prevent discoloration or browning. They are used to preserve smoked and processed meats, dried fruit (e.g., apricots), and salads. In its solid form, sulfites can cause hives when ingested.
Benzoic acid (i.e., benzoate) and Parabens: Benzoates and parabens have antibacterial and anti-fungal properties in order to help with the prevention of food spoilage. These agents are added to pharmaceutical and food products such as drinks (e.g., sugar-free cola). They occur naturally in prunes, cinnamon, tea, and berries. These substances may cause urticaria (i.e., hives), asthma and angioedema (i.e., swelling) in sensitive individuals.
Antioxidants: Synthetic phenolic antioxidants [e.g., BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene)] are typically added to processed foods such as dry cereals and potato flakes in order to prevent the fats and oils in these foods from turning rancid when exposed to air. Unfortunately these antioxidants may trigger asthma, rhinitis, and urticarial in some sensitive individuals.
Aspartame (e.g., NutraSweet, Equal), a low-calorie sweetener, can occasionally trigger itchy hives and swelling of the body. It is also important to note that individuals with genetic condition phenylketonuria should avoid aspartame. Aspartame breaks down into an essential amino acid called phenyalanine which is toxic to individuals with phenylketonuria since these patients are unable to metabolize phenyalanine.
Azo dyes [e.g., tartrazine (i.e., yellow dye #5)] and Non-azo dyes (e.g., erythrocine) can trigger hives, asthma, and generalized allergic reactions.
Nitrates and Nitrites give meat a pink color to look more attractive. These food colorings are typically found in bacon, salami, and frankfurters.
Monosodium Glutamate (MSG) may trigger the “Chinese Restaurant Syndrome” which causes individuals to experience headaches as well as burning and/or tightening of the chest, neck, and face. MSG may be found in soups, pot noodles, and instant drinks, among other foods.
Naturally Occurring Substances:
Vasoactive amines: Natural histamine, serotonin, and tyramine occur in some ripe cheeses, fish, cured sausage, red wine, chocolate, and pickled vegetables and may induce cramping, flushing, headache, and palpitations in a dose-related manner. Of note, there is a condition known as “scombroid poisoning” which occurs in individuals who eat spoiled fish. In this condition, there are abnormally high quantities of histamine in the fish due to improper storage or processing. The typical fish affected may include tuna, mackerel, herring, sardine, anchovy, marlin, and bluefish. The symptoms may include flushing, headache, generalized itching, blurred vision, abdominal cramps, and/or diarrhea. Scombroid poisoning is often wrongly diagnosed as a fish allergy since similar symptoms may be associated with a true fish allergy. One key factor to look for is to see if other individuals eating the same piece of fish exhibited symptoms. If so, it is more likely to be scombroid poisoning due to eating spoiled fish as opposed to a fish allergy.
Caffeine found in foods, medication, tea, coffee, and carbonated beverages induces dose-dependent agitation, palpitations, nausea, and/or tremors.
Salicylates (i.e., aspirin-like naturally occurring chemicals) may induce urticaria, asthma, and/or nasal polyp growth. They are found in curry powder, paprika, oranges, apricots, ginger, honey, berries, fruit skins, tea, and almonds. Salicylate sensitive individuals also tend to have adverse reactions to benzoates and tartrazine.
The precise mechanism how food additives cause reactions is not well understood in many instances. The IgE antibody, which plays a crucial role in immediate-type (i.e., Type I) allergic reactions to food, is usually not involved in adverse reactions caused by food additives.
Skin prick tests and allergy blood tests are not helpful in identifying the food additive culprit in most cases. Careful observation and maintaining food and symptom diaries are sometimes useful in narrowing down the offending additive. Oral challenges under close monitoring in controlled environments may be needed to arrive at a specific diagnosis.
Avoidance of the suspected food additive is the only certain way of preventing adverse effects. One should be vigilant about reading food labels and asking restaurants about ingredients and cooking methods.
If there is a history of anaphylaxis, carrying an epinephrine auto-injector (e.g., EpiPen, Auvi-Q, Adrenaclick) is extremely helpful in emergency treatment. It is important to emphasize that if a self-injectable epinephrine device is used, one should go immediately to the closest emergency room.
The board certified allergists at Black & Kletz Allergy have been diagnosing food additive sensitivitis, food allergies, and food intolerances routinely for many years on both adults and children. Black &Kletz Allergy has 3 convenient locations in the Washington, DC, Northern Virginia, and Maryland metropolitan area. We have offices in Washington, DC, McLean, VA (Tysons Corner, VA), and Manassas, VA which all offer on-site parking. The Washington, DC and McLean, VA locations are Metro accessible and there is a free shuttle that runs between the McLean, VA office and the Spring Hill metro station on the silver line. Please call us to make an appointment or you can click Request an Appointment and we will reply within 24 hours by the next business day. The allergists of Black & Kletz Allergy are eager to help you with your allergy, asthma, sinus, and immunology needs. We are dedicated to providing excellent care and service to you as we have been doing in the Washington, DC metro area for more than 5 decades.