Adverse Reactions to Food Additives
Many people believe that food additives are the source of most negative reactions to foods. In fact, most studies show that a few additives cause problems in relatively few people.
This fact sheet provides general information about the adverse reactions caused by food additives. We hope that this material helps you better understand how food additives can affect people and what steps to take to cope with adverse reactions to them. Please keep in mind that this information is not meant to take the place of medical advice from your own physician.
When 41-year-old Charlie was transferred downtown, he was ecstatic he’d be close to so many ethnic restaurants. After a few months of dining out several times a week, he began to notice a pattern of symptoms on the afternoons after his lunches in certain restaurants. Keeping a log of where he ate and what he ordered, he was easily able to describe his symptoms with his physician, who suggested that MSG—a food additive used by many restaurants— might be the culprit. A follow-up program of testing and elimination of certain foods helped. Charlie figured out how to manage his adverse reactions to this food additive.
What is a food additive?
Substances added to foods and beverages are called food additives. Thousands of food additives exist, and they may be manmade chemicals or natural substances. Common food additives include:
- Vitamins and minerals
- Things which add texture or make foods less acidic
What is an adverse reaction?
In simple terms, an adverse reaction is any undesirable reaction from a food or food additive other than the nourishment the food is supposed to provide to the body. Adverse reactions often depend on your expectations. For example, many people drink coffee and tea so that the caffeine in the beverage will help them stay mentally alert, a desirable effect. In contrast, when we can’t get to sleep at night because we had too much coffee with dinner, the mental stimulant effect of caffeine is an adverse, but understandable, reaction.
Adverse reactions can occur through a variety of mechanisms. Some reactions, such as the stimulant effect of caffeine, are known pharmacologic effects of the chemical, caffeine. Pharmacologic effects typically occur to a greater or lesser degree in all individuals. Adverse effects can also occur because of intolerance to the food. Food intolerances are usually related to individual differences in how a person digests, absorbs, or metabolizes a food. A common example of food intolerance is the symptoms some people get after ingestion of milk because their gastrointestinal tracts cannot breakdown lactose, the sugar in milk. Many other adverse reactions termed idiosyncratic, a fancy way of saying “of unknown cause” are typically rare and will probably someday be understood as uncommon forms of intolerance.
Allergy reactions to foods are another type of adverse reaction to a food. Allergic reactions occur when the body’s immune system recognizes some protein in the food as foreign and tries to prevent the food from entering the body.
What additives cause adverse reactions?
Eight different food additives are commonly known to cause adverse reactions. These are described briefly below.
1. Sulfites. The term, sulfites encompasses a variety of very small chemicals that are commonly used as preservatives in foods. Sulfites prevent foods from turning brown when the food is exposed to air. Some of these are naturally occurring while most are added artificially to foods. Sulfites can cause mild to life- threatening symptoms in some people with asthma. Symptoms of adverse reactions to sulfites include: tightness in the chest, breathing difficulty, hives, stomach cramps, diarrhea, and sometimes, anaphylactic shock. Sulfites are most often found in wine, dried fruits, white grape juice, frozen potatoes, maraschino cherries, fresh shrimp, and certain jams and jellies. At one time, sulfites were used on fresh fruits and vegetables, such as in salad bars, to help retain color and freshness; however, the Food and Drug Administration (FDA) has banned use of sulfites for such use.
2. Aspartame (Nutrasweet) is a calorie-free sweetener used in many foods and beverages. People who have a problem metabolizing the amino acid phenylalanine should not consume aspartame. Many other types of adverse reactions have been reported in relationship to aspartame but these reactions have not been adequately verified to conclude that they are truly caused by aspartame.
3. Parabens are used to preserve foods and medications. They also are used in sunscreens and shampoos where they can cause reactions such as severe contact dermatitis. Examples of parabens are ethyl-, methyl-, propyl-, and butyl-parabens.
4. Tartrazine is a yellow dye most commonly used in beverages, candy, ice cream, desserts, cheese, canned vegetables, hot dogs, salad dressing, seasoning salts, and catsup. Adverse reactions can include hives or swelling, and possibly a trigger for asthma symptoms; however, studies have not documented this relationship. Even though many studies have been done, it has been difficult to find children who consistently adversely react to tartrazine or other food dyes.
5. Monosodium glutamate, glutamic acid (MSG).
Manufacturers and restaurants use MSG to enhance flavor in packaged meats and foods. Adverse reactions can cause headache, a burning sensation on the back of the neck, chest tightness, nausea, diarrhea, and sweating. There are rare reports that people with asthma who have consumed MSG have more severe asthma episodes. “Chinese Restaurant Syndrome”—sudden adverse reactions to eating food from Chinese restaurants—is often attributed to use of MSG in these prepared foods.
6. Nitrates and nitrites are chemicals used to preserve foods, prevent deadly botulism infection, enhance flavors, and color foods. Symptoms are rare, but may include headache or hives in some people. Nitrates and nitrites are commonly used in hot dogs, bologna, salami, and other processed meats and fish.
7. Butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) are preservative chemicals added to breakfast cereals and other grain products to prevent them from changing color, odor, and flavor. These substances have been linked to chronic hives and other skin reactions on rare occasions.
8. Benzoates are preservatives used in some foods, including cakes, cereals, salad dressings, candy, margarine, oils, and dry yeast. Benzoate reactions are very rare.
Good to know . . . There is no evidence that any food additive causes a reaction that lasts more than one day.
Who experiences adverse reactions to food additives?
It is unclear how many people have adverse reactions to food additives. Many people claim to have adverse reactions, but study results have confirmed that food additives actually cause reactions in only a few people. Of the thousands of additives commonly used in various foods, only a handful has been identified as possible causes of adverse reactions.
In 1973, Benjamin Feingold, M.D., claimed that some food additives cause children to be hyperactive. Dr. Feingold developed a diet low in salicylic acid, artificial colorings, and artificial flavors. He claimed that close adherence to this diet would reduce hyperactivity in children.
Other researchers have been unable to show that the diet works for more than just a few children. In 1982, a National Institutes of Health (NIH) team of experts concluded that scientific findings do not support the claim that food additives cause hyperactivity. Studies since then support those findings.
The Feingold diet does not normally cause physical harm. Children who are needlessly on the diet, though, may be emotionally and socially harmed, pediatricians warn. Diets can be emotionally and socially harmful when parents zealously pursue a needless and restrictive diet. One or both parents may hover over a child whenever the child eats making meal time ordeals for the child. The parent(s) may also restrict a child from activities such as going to a birthday party for fear that he or she will ingest a food additive. These restrictions may be applied to one child but not to other children in a family creating major tensions in the family.
What are the symptoms of an adverse reaction to food additives?
Symptoms vary in type and degree. They depend on the additive causing the reaction, how sensitive the person is to the product, and the amount consumed. Most reactions are pharmacological or idiosyncratic, not allergic. People who react to one food additive are not likely to react to other unrelated chemicals.
How is an adverse reaction to food additives diagnosed?
Symptoms of an adverse reaction to specific foods are the best indicator that certain food additives may be a problem for you. Consult your physician if you experience any negative reactions to foods. Come prepared to describe your symptoms, when and how often they occur, and what happens when you eat these foods. It is often very helpful to keep a list or diary of when you have had reactions after eating and exactly what foods you ate.
To confirm that an additive is causing a reaction, you can control your diet. If the symptoms never occur when your diet is free of an additive and return when you ingest the additive, you can be relatively sure that the additive is causing your symptoms. The treatment is to then keep the additive out of your diet. If it is not possible to establish a clear cause and effect relationship by controlling your diet, you may want to undergo a blinded challenge in a special center. Neither you nor your physician should know if the additive is in the food. During the test you will be watched to see if there is any change in your symptoms. If your symptoms return when you are given the food with the additive, a diagnosis of intolerance to the additive will be confirmed.
What is the best way to manage an adverse reaction to a food additive?
The only way to prevent an adverse reaction to a specific food additive is to avoid the additive. Here are some general practices to use to help manage adverse reactions to food additives.
• Avoid consuming any food additives, which you know will cause problems for you.
• Read ingredient lists on all food labels carefully.
• Be sure you know the different ways an additive is named. (For example, BHA in place of butylated hydroxyanisole).
• Find out whether there are other additives, which are in the same “family” or similar to the additives you cannot use. Avoid these as well.
• Avoid sulfiting agents by looking for sulfur dioxide; sodium or potassium sulfite; bisulfite; or metabisulfite in ingredient lists.
• Question restaurant staff about ingredients, cooking methods, and what other foods or additives may come in contact with food you want to order. Don’t be afraid to ask that your food be prepared according to your needs.
• If you have a serious adverse reaction to a food additive, wear a Medic Alert bracelet or necklace to inform physicians of your sensitivities to specific substances/foods in case of emergency.
• If anaphylaxis is a concern, always carry injectable epinephrine for use in an emergency.
Who should treat this particular aspect of asthma/allergies?
Many patients are treated for allergies by their internist, family physician, or pediatrician. However, if your adverse reactions to food additives are not under control within 3-6 months, or if you have severe persistent symptoms, or if you are having attacks that need emergency treatment, it may be time to see a specialist. Allergists/immunologists or pulmonologists (who specialize in the treatment of lung diseases) are specialists who treat asthma and allergies. Those who have completed training in those specialties are usually called board-certified or board-eligible. Check Where can you find more information about asthma or allergies? below for more information about finding a specialist.
Does health insurance cover treatment for adverse reactions to food additives?
Most health insurance plans provide some level of coverage for allergy patients. Check with your insurance carrier for details. Some things you may want to find out might include:
• Do you need a referral to an allergy/asthma care specialist from your internist, family physician, or pediatrician?
• Does the insurance carrier offer any patient education or specialized services related to allergies? Food additives? Food allergies?
• Does the insurance provider consider this a pre-existing condition? If so, what coverage is offered for pre- existing conditions?
• What medications are not covered by your plan? (There can sometimes be a delay in approving newly released medications. Your physician may know about them, but your insurance may not cover them yet.)
The information provided in this fact sheet should not be a substitute for seeking responsible, professional medical care.
Reprinted with permission from “Asthma and Allergy Answers,” the patient education library developed by the Asthma and Allergy Foundation of America.