Many people believe that food additives cause most food reactions. In fact, natural foods cause most reactions. Studies have found, though, that a few additives do cause problems in a few people.
What Is A Food Additive?
Thousands of man-made and natural substances are added to the food and drink we consume. Some of these additives are vitamins and minerals to improve our health and preservatives to slow decay. Others enhance flavor or color, add texture and make foods less acidic.
Who Has Adverse Reactions to Food Additives?
It is unclear how many people have adverse reactions to food additives. Many people claim to have them, but study results have confirmed that food additives cause reactions in only a few people. And of the thousands of additives used, only a handful have been identified as possible causes of adverse reactions.
A report that sparked public interest in adverse reactions to additives was published in 1959. It reported that three patients developed hives after taking tablets that contained tartrazine. Tartrazine, also known as FD&C yellow No. 5, is used to add yellow color to food. Today, scientists question the process used by those researchers to connect taking tartrazine with developing hives. At that time, though, the report convinced more people they should look into additives as the possible source of various reactions.
In 1973, Benjamin Feingold, M.D., claimed that some food additives cause children to be hyperactive. Symptoms of hyperactivity, or attention deficit disorder, include nervousness, short attention span and aggressiveness. Feingold developed a diet low in salicylic acid (a salt), artificial colors and artificial flavors such as aspartame. He claimed that close adherence to the diet reduced hyperactivity in children.
Other researchers have been unable to show that the diet works for more than 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 cause physical harm. Children who are needlessly on the diet, though, may be emotionally and socially harmed, pediatricians warn.
What Are the Symptoms of Food Additive Reactions?
Symptoms vary in type and degree. They depend on the additive causing the reaction, how sensitive the patient is to the product and the amount consumed. Most reactions are chemical, not allergic reactions. People who react to one chemical are not likely to react to others.
The most serious reaction to a food additive is anaphylactic shock. This is a life-threatening condition that includes breathing problems and loss of consciousness, among other physical reactions. It usually occurs within minutes after consuming the additive. When this happens, blood vessels widen so much that blood pressure plummets. Symptoms include sweating, paleness, panting, nausea, rapid pulse, faintness, confusion and even passing out. Without speedy treatment, this intense allergic reaction can cause death.
What Additives Cause Reactions?
There are eight additives that may cause reactions:
Sulfites can cause mild to life-threatening symptoms in approximately 5 percent of people with asthma. Symptoms include chest tightness, hives, stomach cramps, diarrhea, breathing problems and other symptoms of anaphylactic shock. Experts suspect that the reactions are caused by a hyper-reaction to inhaled sulfur dioxide. Some products sulfites can be found in wine, dried fruits, white grape juice, frozen potatoes, maraschino cherries, fresh shrimp, and certain jams and jellies. Sulfites at one time were used on fresh fruits and vegetables to retain color and freshness. The Food and Drug Administration, which governs the use of food additives, has banned them from such use.
Aspartame (Nutrasweet) is a calorie-free sweetener. Most reported reactions, include "hives," swelling of the eyelids, lips or hands and headaches. But these reactions have not been verified. People who have a problem breaking down the amino acid, phenylalanine, should not consume aspartame. Some claim the product also causes hyperactivity in children, but study results do not support these claims.
Parabens are used to preserve foods and medications. Some examples of parabens are ethyl, methyl, propyl, butylparabens, and sodium benzoate. In sunscreens and shampoos, they can cause severe contact dermatitis. This is a skin condition that causes redness, swelling, itching and pain. But adverse reactions to foods containing parabens have not been clearly shown in studies.
Tartrazine is a dye used in beverages, candy, ice cream, desserts, cheese, canned vegetables, hot dogs, salad dressings, seasoning salts, catsup and some other foods. It may be associated with hives or swelling; although suspected of causing asthma attacks, recent studies suggest that this is unlikely. A 1983 scientific review of studies led experts to conclude that no more than 2 percent of children react to dye additives. These reactions are very rare in recent studies.
MSG (monosodium glutamate, or glutamic acid) forms 20 percent of dietary protein. MSG is used in Oriental foods and in manufactured meat, poultry and other products by manufacturers and restaurants to enhance flavors. It is believed to cause "Chinese Restaurant Syndrome." A patient may have a headache, a burning sensation on the back of the neck, chest tightness, nausea, diarrhea and sweating. There have been rare reports that people with asthma who have consumed MSG have more severe asthma attacks. This is still being researched.
Nitrates and nitrites are used to preserve foods, prevent deadly botulism infection, enhance flavors and color foods. They may rarely cause headaches and hives in some people. Nitrates and nitrites are used in hot dogs, bologna, salami and other processed meats and fish.
BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole) are added to breakfast cereals and other grain products to prevent them from taking in oxygen and changing color, odor and flavor. They have been linked to chronic hives and other skin reactions on rare occasions.
Benzoates are preservatives for some foods including cakes, cereals, salad dressings, candy, margarine, oils and dry yeast. Benzoate reactions are very rare.
How Are Reactions to Food Additives Diagnosed?
Today, scientists would demand stricter control of the process reported in 1959 to diagnose tartrazine as the cause of the hives. They question if other claims of adverse reactions to food additives are based on properly controlled studies showing a relationship.
You may have reason to believe that you have adverse reactions to certain food additives. If you do, remove the additives from your diet for a few days. Your symptoms should promptly go away if the additive is the cause. There is no evidence that any food additive causes a reaction that lasts more than one day.
To confirm that an additive is causing a reaction, a controlled study can be done. The food additive should be added and removed from the diet. Neither the patient nor the physician should know if the additive is in the diet. The patient should then be watched to see if there is a change in symptoms. Symptoms should improve when the food is removed from the diet.
How Can I Prevent a Reaction?
The only way to prevent a reaction is to avoid the cause. To make sure you do not unknowingly consume the product, carefully read ingredient lists on food labels, and question restaurant staff about cooking methods.
To avoid sulfiting agents, look for sulfur dioxide, sodium or potassium sulfite, bisulfite, or metabisulfite in ingredient lists.
Tips for Follow-up
If you have had a serious adverse reaction to a food additive, wear a Medic-Alert bracelet or necklace to alert health care providers of your allergy in case of an emergency. If anaphylaxis is a concern, always carry adrenaline in a syringe, such as EpiPen or Ana-Kit, for injecting in an emergency.
Report adverse reactions to the Food and Drug Administration's Adverse Reaction Monitoring System. The agency will look into the possibility that the additive is a public health hazard.
If you use the World Wide Web to read about reactions to food additives, look closely at the source of the information to judge the validity of the information.
SOURCE: This information should not substitute for seeking responsible, professional medical care. First created 1995; fully updated 1998; most recently updated 2005.
© Asthma and Allergy Foundation of America (AAFA) Editorial Board