Food Allergies
FOOD ALLERGIES – SEPARATING FACT FROM “HYPE”, Richard C. Thompson
Reprinted from the June, 1986 issue of FDA Consumer, a publication of the Food and Drug Administration.
Americans’ fascination with so-called health foods began its present cycle about 20 years ago and has not yet run its course. But now there is also a fascination with foods and food ingredients that are seen as unhealthy, that supposedly can produce mild to severe mental, physical and emotional symptoms and cause changes in work performance and social behavior.
It seems to be the other side of the health food coin, and it has an appealing, simplistic logic: Some foods are good; others are bad, at least for you. So if you have or think you have symptoms of whatever kind that cannot be explained to your satisfaction, blame it on a “food allergy.”
Those who encourage the belief that food allergies are everywhere are usually promoting products and theories. Some are opportunists; others have worked out their own private theories of illness and disease, often with little regard for scientific fact.
But Dr. Jordan Fink, chief allergist at the Medical College of Wisconsin and past president of the American Academy of Allergy and Immunology (AAAI), puts the whole issue in perspective.
We are talking about less than 2 percent of the American population as having true food allergies, he says. Among adults who are thoroughly tested, he continues, “perhaps five percent who think they have allergies will turn out to have one.”
Science writer Jane Brody of the “The New York Times” says the link between what people eat and how they behave is being recklessly expanded, “with everything from intellectual performance and muscular prowess to hyperactivity and criminality now related–without justification–to consumption of various foods and their constituents.”
She sees this as having some strange results. “In homes, schools and institutions around the country,” she writes, “hyperactive children, prisoners and juvenile delinquents are being placed on special diets that restrict sugars, additives and in some instances, milk, in the belief that this can improve their disruptive behavior.
“In California, for example, the county juvenile justice systems have changed the way that detained juveniles are being fed. The specifics may vary but all seek to reduce sugars and additives. Dr. Stephen Schoenthaler, whose preliminary findings on diet and antisocial behavior may have triggered these measures, says educational and correctional institutions in 44 states have asked his office for help in changing dietary practices,” according to Brody.
She adds that there is a price to pay for this misapplication of scientific research. “In attributing criminal or delinquent behavior to a food allergy or sensitivity, the person in effect is excused from that behavior.”
The most bizarre use of this theory may be the “Twinkie” defense that helped win a reduced penalty in 1978 for a murderer in San Francisco. The defense claimed, and the jury accepted the premise, that the defendant’s habit of overeating surgary snack foods, potato chips, soft drinks, and the like produced his violent behavior. With that success–the charge reduced from murder to manslaughter–a number of lawyers handling criminal cases began seeking acquittal of their clients on the basis of “temporary insanity induced by a food-caused mental derangement.”
Hoping to control their hyperactive children, many parents will not allow them to eat foods that contain artificial colors and flavors and added sugar. This widely used diet became popular after reports by the late Dr. Benjamin Feingold that such diet restrictions would affect the often frantic behavior of these children. Even though repeated studies do not support these claims, some parents–not wanting to medicate their children–opt for the diet over drug treatment shown to be effective.
Those who claim–for whatever reason–that dietary changes will produce dramatic improvements in behavior are not willing to wait for scientific confirmation. They do not care that the treatment may be unscientific or that the apparent benefits could be a placebo effect or the result of other variables. What matters is that it seems to work.
Public acceptance of links between diet and behavior is alarming to serious medical researchers, who say that the evidence that certain foods might affect emotions and behavior is not ready to be put to use.
Dr. Richard Wurtman, neuroendocrinologist at the Massachusetts Institute of Technology, was one of the first to show that foods can affect the brain. He says that food allergy studies are being applied before they have been confirmed as scientific fact. He is uneasy that anecdotal evidence about dietary effects is being accepted as truth and “solidified as social policy.”
Dr. Michael Youngman, pediatric researcher at Harvard, says people are much too ready to apply study results, that work in this area is only beginning.
Dr. John Crayton of the University of Chicago is another researcher who has found a possible link between food and mood but is quick to point out the limitations of such findings. In his study, a group of 35 volunteers–some with complaints of food sensitivity–were fed capsules of powdered wheat, milk or chocolate, foods often associated with allergies. He found that changes in mood, coincidental with changes in their immune systems, did occur in this group. He theorized that food-induced reactions may cause local swelling in the brain that leads to mood swings, but cautions that this is early work and not yet understood.
In its patient’s guide, the AAAI says that a true food allergy is a response in which the body’s immune system overreacts to substances in food. These responses occur in very few people, are usually the result of a genetic factor, and can be noticed almost at once when only a small quantity of a food has been eaten. Infants with certain food allergies may outgrow them as their immune systems mature.
Those parts of food that cause reactions are called allergens. They are usually proteins, and the body responds through its immune defense system– as it should–to what it thinks are threatening foreign invaders. The most common protein allergens in the United States, according to the AAAI, appear to be cow’s milk, egg white, peanuts, wheat and soy, although shrimp, tomato, codfish and crab contain proteins to which some people are allergic, too. Cooking can reduce the effect of some protein allergens but may increase the effect of others.
A food allergy may show up as hives, a skin reaction in which red, itchy, swollen areas suddenly appear, then soon disappear. Eye and nasal symptoms-
-like those of hay fever–seldom are caused by food allergies. The AAAI says that the breathing difficulty known as asthma may–in infants–be caused by a food, but foods are not thought to play a frequent role in triggering asthma in adults.
Patients with suspected food allergies will be given a complete physical examination and asked by their doctor about the frequency, severity, seasonality and nature of their symptoms.
They may have to keep a “food diary” of all they eat; they may have to eliminate certain foods, one by one, to discover which–if any–are at fault; they may have to participate in double-blind studies in which neither they nor their doctor know at the time the food they are eating.
Skin testing with a liquid extract of suspect foods may be used, but the technique is not as reliable as when testing for pollen allergies. Blood tests are also useful for diagnosis for some patients in some instances.
Promoters of unproved methods for detecting food allergies–who are adept at linking food, mood and behavior–say that everyone is at risk and that their tests will find your allergy. But everyone is not at risk and there’s no evidence that cytotoxic testing–dropping food extracts on a patient’s white blood cells in a laboratory dish–or sublingual testing–placing a bit of the suspect food under the patient’s tongue–will detect anything.
One recognized food allergy is a reaction to sulfites. These are preservatives added to foods, usually during manufacturing but sometimes at the point of sale, as with some restaurant salad bars. Sulfites are harmless to most people but can cause reactions that are severe and sometimes fatal to those sensitive to them, especially to persons with asthma. FDA requires that products containing sulfites be labeled so that consumers who wish to can avoid them. Less than 1 percent of the population is thought to be sensitive to sulfites. (For more information, see “Reacting to Sulfites” in the Rare Disease Reference Materials.)
Nuts are another allergen that can be threatening. The recent death from anaphylactic shock of a college student in Providence, Rhode Island, who ate chili that–unknown to her–contained peanut butter prompted health officials to ask that restaurants list “highly unusual ingredients” that are in their foods. The officials are also encouraging patrons to ask about the ingredients in a restaurant’s food. Also, Providence ambulances will now carry adrenalin to treat persons suffering from anaphylactic shock (a collapse of the vascular and respiratory systems), which can occur in a severe allergic reaction to food.
The AAAI recommends that persons who have experienced anaphylactic shock wear a bracelet that identifies their allergy and carry an emergency kit that contains epinephrine (adrenalin) to immediately treat any such reaction.
A migrane-like reaction to certain foods can also indicate a food allergy. The British medical journal “Lancet” (Sept. 29, 1984) described a test in which patients with a history of migraine headaches had meals containing egg, milk and wheat (foods known to produce symptoms in these patients). The test confirmed that migraine in these particular cases was an immune response to an allergen.
Public interest in food allergies–real or imagined–will not go away, according to Dr. A. Elizabeth Sloan, director of the Good Housekeeping Institute. In fact, she said, it has the potential to become the major consumer food issue of the next decade.
Sloan said a survey by “Good Housekeeping” showed that 30 percent of the women interviewed believed that they or a member of their families were allergic to a food or food ingredient. Twenty-two percent said they actually avoided certain foods on the chance that they might contain an allergen.
Their greatest concerns were with sulfites, the artificial sweetener aspartame, the color additive tartrazine (FD&C Yellow No. 5), and the flavor enhancer monosodium glutamate. The women’s fear of having an allergic reaction to food ingredients was comparable to their fear of getting cancer from certain additives, a marked increase from surveys taken in previous years by the magazine.
Sloan said that it is essential to find the true incidence of allergic reactions to these and other food substances. If only a few in the population are sensitive to it, she says the ingredient should be noted on the label. If it is found to be a risk to a great many people, the ingredient should no longer be used or the amount used should be reduced so that it does not cause a reaction.
To give FDA a better understanding and database on the extent and seriousness of allergic reactions to food, the agency has established a new reporting and surveillance system in its Center for Food Safety and Applied Nutrition.
Using reporting forms like those long used for adverse drug reactions, physicians and other health professionals are being asked to inform FDA of any severe and well-documented allergic reactions to food.
The center currently monitors adverse reactions to sulfites and aspartame and needs to receive reliable information on reactions that appear to be associated with these or similar foods, food additives, and dietary practices.
The new allergic reaction reporting system will be an adjunct to the center’s system for reporting illness or injury caused by microbial contamination and adulterated food products.
Microbial contamination can cause food poisonings such as salmonellosis, but the illness is not allergic in nature. The new system will not duplicate reporting of food poisonings already being coordinated by the states and the U.S. Centers for Disease Control.
Reports to FDA of allergic reactions will be investigated by the FDA field office that receives the complaint.
The headquarters emergency operations staff receives copies of all consumer complaints that come to agency field offices. Currently, FDA receives 12,000 to 15,000 consumer complaints of all kinds each year. Some 70 percent of these are food related. The others are reports of illness or injuries related to medication, medical devices, and other products that FDA regulates.
Health professionals who become aware of non-microbial (allergic) reactions to foods can report the incident by using the form on the back of the FDA Drug Bulletin that is mailed several times a year to 1 million physicians and other health professionals in the United States.
In addition to the new reporting system, FDA has established an advisory committee on hypersensitivity to food constituents. In announcing the committee, Commissioner Frank E. Young, M.D., noted that–because medically accepted tests for sensitivity have never been conducted on a large segment of the population–accurate estimates of adverse reactions to foods cannot be made.
The committee will consider the prevalence of allergic reactions, the need for research, the effectiveness of present labeling for hypersensitive substances, methods to protect that small part of the population that is sensitive to substances that are harmless to the general population, and other aspects of reactions to foods and food ingredients.
Consumers who feel they may be allergic to some food or food ingredient in their diet should discuss the matter with a physician. There are legitimate tests that can help determine whether a food is really at fault, but they can be fairly expensive, time-consuming, and will require a good deal of dedication on the part of the patient in controlling diet and scrupulously keeping track of what foods are consumed. But those who blame their state of mind on the state of their diet should remember that–despite all the attention given to the food, mood and behavior link–the evidence that does exist shows that such relationships are rare.