A food allergy is an adverse immune response to a food protein.Food allergy is distinct from other adverse responses to food, such as food intolerance, pharmacological reactions, and toxin-mediated reactions. The protein triggering the allergic response is termed a food allergen.
|adverse immune response to a food protein||caffeine tremors, cheese/wine (tyramine) migraine, scombroid (histamine) fish poisoning||bacterial food poisoning, staphylotoxin||lactose intolerance (lactase deficiency)|
Treatment consists of either immunotherapy (desensitisation) or avoidance, in which the allergic person avoids all forms of contact with the food to which they are allergic. Areas of research include anti-IgE antibody (omalizumab, or Xolair) and specific oral tolerance induction (SOTI), which have shown some promise for treatment of certain food allergies. People diagnosed with a food allergy may carry an autoinjector of epinephrine such as an EpiPen or Twinject, wear some form of medical alert jewelry, or develop an emergency action plan, in accordance with their doctor.
Prevalence in the U.S.
In the United States, it is estimated that up to twelve million people have food allergies, and the prevalence is rising; six to eight percent of children under the age of three have food allergies and nearly four percent of adults have them.
Food allergies cause roughly 30,000 emergency room visits and 100 to 200 deaths per year in the United States. The most common food allergies in adults are shellfish, peanuts, tree nuts, fish, and eggs, and the most common food allergies in children are milk eggs, peanuts, and tree nuts.
Signs and symptoms
Classic immunoglobulin-E (IgE)-mediated food allergies are classified as type-I immediate hypersensitivity reactions. These allergic reactions have an acute onset (from seconds to one hour) and may include:
- Angioedema: soft tissue swelling, usually involving the eyelids, face, lips, and tongue. Angioedema may result in severe swelling of the tongue as well as the larynx (voice box) and trachea, resulting in upper airway obstruction and difficulty breathing.
- Itching of the mouth, throat, eyes, skin
- Nausea, vomiting, diarrhea, stomach cramps, and/or abdominal pain. This group of symptoms is termed gastrointestinal hypersensitivity.
- Rhinorrhea, nasal congestion
- Wheezing, scratchy throat, shortness of breath, or difficulty swallowing
- Anaphylaxis: a severe, whole-body allergic reaction that can result in death (see below)
The reaction may progress to anaphylactic shock: A systemic reaction involving several different bodily systems including hypotension (low blood pressure),loss of consciousness, and possibly death. Allergens most frequently associated with this type of reaction are peanuts, nuts, milk, egg, and seafood, though many food allergens have been reported as triggers for anaphylaxis.
Food allergy is thought to develop more easily in patients with the atopic syndrome, a very common combination of diseases: allergic rhinitis and conjunctivitis, eczema and asthma. The syndrome has a strong inherited component; a family history of allergic diseases can be indicative of the atopic syndrome.
Conditions caused by food allergies are classified into 3 groups according to the mechanism of the allergic response:
1. IgE-mediated (classic):
- Type-I immediate hypersensitivity reaction (symptoms described above)
- Oral allergy syndrome
2. IgE and/or non-IgE-mediated:
- Allergic eosinophilic esophagitis
- Allergic eosinophilic gastritis
- Allergic eosinophilic gastroenteritis
3. Non-IgE mediated:
- Food protein-induced Enterocolitis syndrome (FPIES)
- Food protein proctocolitis/proctitis
- Food protein-induced enteropathy. An important example is Celiac disease, which is an adverse immune response to the protein gluten.
- Milk-soy protein intolerance (MSPI) is a non-medical term used to describe a non-IgE mediated allergic response to milk and/or soy protein during infancy and early childhood. Symptoms of MSPI are usually attributable to food protein proctocolitis or FPIES.
- Heiner syndrome – lung disease due to formation of milk protein/IgG antibody immune complexes (milk precipitins) in the blood stream after it is absorbed from the GI tract. The lung disease commonly causes bleeding into the lungs and results in pulmonary hemosiderosis.
Food Allergy, Basic Concepts
The concept of food allergy and foods causing medical illness is the basis of much controversy and heated emotional responses on both sides of the argument. Most articles in the conventional medical literature state that true food allergy is rare and not usually a factor in the general medical evaluation of a patient’s symptoms. Because numerous offending foods may produce a multitude of symptoms in many different organ systems, most traditional physicians have difficulty understanding and accepting this concept. Medicine likes the nice neat “cause and effect’ paradigm like streptococcus germ as the cause of Strep throat which is cured with antibiotics. The myriad of resultant symptoms from food intolerance, both immediate and delayed, that can affect almost any body area or organ system and that can change in severity based on the total allergic load of the individual is just too “messy” to make most physicians comfortable. This situation is, however, slowly changing. At the Annual Congress of the American College of Allergy in 1986, William D. Kniker, M.D. told his fellow physicians that it is no longer reasonable to limit management of allergy in patients to classic atopy (immediate reactions) that principally involve inhalant triggers (dust, molds, pollens) and respiratory symptoms. “The full spectrum of adverse reactions to foodstuffs must also be considered,” recommended Dr. Kniker, Professor of Pediatrics and Microbiology and the Director of Pediatric Clinical Immunology and Allergy at the University of Texas Science Center.
The concept of food triggered hypersensitivity reactions was pioneered in the 1930’s by Dr. Arthur Coca. At the same time period Dr. Albert Rowe developed elimination diets to diagnose and treat food allergy. These concepts were expanding in the 1950’s by Drs. Rinkel, Randolph and Zeller. Dr. Randolph may rightly be called the father of Environmental Medicine as he maintained that 2/3’s of symptoms diagnosed as psychosomatic are undiagnosed maladaptive reactions to foods, chemicals and inhalants. For a complete scientific review of Food Allergy, the reader is referred to the thousand page medical text, Food Allergy and Intolerance by Brostoff J and Challacombe, S Bailliere Tindall, London. 1987. For more information on Allergy and Environmental Illness, see our separate monograph with the same title.
Beyond the Basics: Allergy vs. Sensitivity & Immediate vs. Delayed
Much confusion and misunderstanding centers around the word “allergy”. The word allergy is derived from two Greek words meaning “altered reaction”. The substance which provokes a reaction in an individual is called and “allergen” or “antigen”. This can be food, dust, mold, pollen or other substances. When medicine began to scientifically understand allergy in the 1930’s, they discovered a biochemical pathway in the body that caused the typical Hayfever symptoms we all know so well. This involved an immune compound in our blood and tissues called Ig E which was responsible for an immediate allergy reaction: exposure to ragweed caused sneezing, itching and watery nose. It is this definition of allergy that became accepted by the medical community. As time and medicine progressed, it was discovered that other pathways in the body also lead to specific symptoms and could produce delayed reactions.
Whereas immediate reactions occur within minutes to several hours after exposure to an allergen, delayed reactions can occur anywhere from 12 to 72 hours after exposure to an allergenic food or substance. These delayed pathways are still not well understood and are probably the mechanism by which foods, chemicals and other substances produce most physical symptoms. Unfortunately, this does not fit into the classic example of “immediate type Ig E allergy” and thus the concept of delayed food and chemical allergy has been very difficult for the medical community to accept. Consequently, we prefer the word “sensitivity” or “intolerance” to describe any reaction to a food, chemical or other substance that does not fit the classic “immediate type Ig E allergy” mechanism.
We thus have several mechanisms and corresponding words that describe food triggered symptoms. Food allergy generally refers to the specific situation where an immediate and readily identifiable food reaction occurs in the respiratory, digestive or skin systems. These symptoms include sneezing, itching and hives. Food sensitivity includes these limited immediate food allergy symptoms and also includes any other immediate or delayed symptom or reaction to a food substance. The resultant symptoms are immediate if identifiable within several hours after the ingestion or are delayed if reaction occur 12 hours later or for some times up to 4 or more days after the food contact. Delayed reactions are almost always “hidden” and are subsequently difficult to identify.
Hidden food sensitivity causes some of the most common, chronic and incapacitating illnesses in today’s society. The symptoms may not emerge noticeably until long after eating the causative foods, and many foods may be causing symptoms simultaneously. Therefore, many such patients suffer puzzling illnesses and are chronically sick. Unfortunately, they are not usually aware that foods have anything to do with their problems.
Symptoms and Conditions Related to Food Sensitivity
As stated, food sensitivity symptoms can include any body area and organ systems. If you have any of these symptoms or conditions, they may be caused or aggravated by food sensitivity. The symptoms and conditions related to food sensitivities1 may include, but are not limited to the following:
Head: chronic headaches2, sinus headaches, migraines3, 4, 5, difficulty sleeping, dizziness, red face
Eyes, Ears, Nose and Throat: runny or stuffy nose, post nasal drip, ringing in the ears, red ears, earaches, vertigo, blurred vision, eye pain, conjunctivitis, dark circles under eyes, bad breath, geographic tongue, mouth ulcers, recurrent upper respiratory infections and colds, recurrent ear infections6
Heart and Lungs: irregular or rapid heart beats, palpitations, high blood pressure, asthma, wheezing, chronic cough
Gastrointestinal7: Infantile colic8, nausea and vomiting, diarrhea, loose stools, constipation, irritable bowel syndrome, colitis (Crohn’s Disease and Ulcerative Colitis), stomach/duodenal ulcers, reflux, heartburn, indigestion, gall bladder conditions, malabsorption syndromes
Kidney, Bladder and Reproductive: bed wetting, cystitis, interstitial cystitis, recurrent urinary tract infections, blood in urine, nephritis, glomerulonephrosis, recurrent vaginitis, PMS
Skin: hives, eczema, psoriasis, acne
Muscles and Joints: muscle and joint pain, arthritis, lupus, muscle weakness
Overall and Others: fatigue9, hypoglycemia, starch and sugar cravings, hyperactivity and attention deficit10, 11, 12, behavior problems, learning problems, convulsions, bulimia, obesity, anxiety, panic reactions, depression, mental dullness, memory lapses, mood swings and irritability, anger outbursts, difficulty thinking13.
Which symptom or symptoms occur depends entirely upon the person and most likely their genetic inheritances. While any body system can be affected, most allergy sufferers have a “target” organ or organs that are affected by the sensitivity reaction. For some this may be the nose (chronic nose congestion and post nasal drip), for others it may be the brain (headaches, confusion, depression). Some will experience the same symptom each time they have a food reaction, regardless of which food is ingested. Others will report different symptoms for each different allergic food.
Reasons Why Your Hidden Food Sensitivities May Not Have Been Detected
Most of us can recognize an immediate food reaction (like sneezing five minutes after eating a tomato) and a few of us can recognize some foods which cause delayed symptoms, particularly if they are eaten infrequently. However, for the ten reasons listed below, most delayed type food reactions are not known to the patient and his or her physician.
1. Summation of Feedings
Food molecules are absorbed into the bloodstream when it enters the mouth, and absorption continues for about three or four days. However, it may last up to seven or more days in some instances, particularly in the presence of constipation.
When a food is eaten daily or several times daily, a high blood level of that food is maintained. Then a reaction to a given food occurs while the patient is still reacting to one or more previous meals of the same food, and may also be reacting to one or more previous meals of other allergenic foods as well. Symptoms thus tend to be almost chronic. They seem unrelated to a given meal or a given food.
Anything that causes an increased rate of absorption of a food from the digestive tract is more apt to cause the emergence of symptoms. Increased rates of absorption can occur from intestinal diseases, diarrhea, or taking alcoholic beverages with the food. It can also occur when eating the food on an empty stomach such as when first arising in the morning. Exercising vigorously soon after taking an allergenic food also seems to increase the rate of emergence of symptoms.
2. Delayed and Prolonged Reactions
One problem that has made delayed food allergy difficult to diagnose in the past is that most physicians did not realize that a reaction, even a sudden, severe one, may occur so late and continue for so long a time after a given allergenic food is eaten even once. We did not recognize that such a reaction might not begin or noticeably emerge for many hours and might then last or recur repeatedly for days.
Furthermore, the individual may have eaten several meals in the past few days so that all these portions of the food are absorbing almost simultaneously from different segments of the gastrointestinal tract, causing daily or chronic symptoms.
3. Great Number of Food Ingredients in the System
Most people eat three or more meals daily. Each meal usually contains at least five to ten food ingredients. These foods continue absorbing for about three days. Simple arithmetic tells us that we can consume 15-30 different foods per day or 45-90 over a three day period. All these could potentially influence our immunologic mechanisms. This is a conservative figure since many processed foods such as bakery products, packaged cereals, dried or canned mixtures, mayonnaise, salad dressing, etc., may contain dozens or scores of ingredients. So a person on an average diet may have several hundred food ingredients in his gastrointestinal tract and bloodstream any time. These are not all allergenic, but the potential is there, increasing the difficulty of detecting individual allergens.
4. Patients May be Sensitive to Many Foods
It is not uncommon to see patients with hidden allergies to thirty or more foods who, on initial history can incriminate only a few foods, such as tomatoes, oatmeal and apples. Many patients suffering from recurrent headaches know only that if they eat chocolate today, they will probably awaken tomorrow in the early morning hours with a severe headache.
What they do not realize is that the headaches they have on many days when known allergenic foods are not eaten are due to milk, wheat, corn, soy, egg, beef, and possibly other staple foods they eat daily or frequently. This range of allergens represents a near-impossible tangle which few patients can recognize, much less sort out, without help.
5. Related Bursts of Absorption
An allergenic food eaten for dinner one evening may not cause any symptoms that evening or during sleep. However, when a non allergenic meal is eaten the next morning, the reawakening of the gastrointestinal tract apparently results in renewed absorption of the allergenic food eaten the day before.
This finally brings forth symptoms. The allergenic food was eaten only once, but the increased burst of absorption occurred twice, boosting the blood level and producing symptoms in the same manner as though it had been eaten twice.
The patient may have his headache or stomachache repeatedly after several consecutive non allergenic meals, from an allergenic food eaten only once but absorbed again in bursts after subsequent meals. He may never pinpoint the causative food because he did not eat it at each meal. This is also one reason some patients who are put on entirely allergen-free diets or total fasts will continue to have symptoms periodically for two, three, or more days before obtaining relief.
6. Varying Thresholds and Mediator Levels
One may also have an “asymptomatic sensitivity” to some foods. In this instance, the patient may have no symptoms when any one of these foods is eaten once or alone. However, he may have symptoms when eating one allergenic food twice at close intervals, or repeatedly or when eating several “asymptomatic” allergenic foods together or at close intervals.
This phenomenon suggests that the blood mediator levels may be elevated by a single feeding, but not always to the level of the symptom threshold for that food. Eating one allergenic food repeatedly or eating two or more allergenic foods together or at close intervals, or eating an allergenic food while being exposed to an allergenic inhalant may further elevate the mediator level. Thus the mediator level finally exceeds the symptom threshold resulting in illness.
7. Additive Effect of Nonfood Stressors
Puzzling symptom fluctuation in the same patient may also be produced at times by nonfood allergens. A food-sensitive patient may also be sensitive to inhalant particles, chemicals, or drugs. The same symptoms initiated by allergic stresses may also by precipitated by a nonallergic stress or triggering factors such as irritating chemicals, infections, intestinal bacterial, parasitic or yeast (Candida) overgrowth conditions (Intestinal Dysbiosis), chilling, exercise, fatigue, season, weather, environmental changes, the change of daylight, varying rates of gastrointestinal absorption, menses, and emotional stressors.
In our experience, pesticides and chemicals in foods appear to be a significant contributor to the development and perpetuation of food sensitivities. We hear and observe over and over those who cannot tolerate a certain food item obtained from regular commercial sources, but are perfectly able to tolerate the same food in its organic and chemical free state. Although the mechanism of how chemicals and pesticides contribute to the development of food sensitivities is not totally understood, one explanation is that they weaken the intestinal and digestive tract contributing to the Leaky Gut Syndrome (see separate monograph). This condition allows for the increased absorption of larger food molecules which results in an abnormal immune system response.
The role of stress cannot be easily overlooked. A dramatic example is illustrated in one patient with positive food allergy testing to only two foods: peanut butter and bananas. Since many food sensitivities result from constant ingestion and exposure to our favorite foods, she was questioned about her intake of these foods. She stated that she hated these two foods and never ate them. Further investigation revealed that during her childhood she was forced to eat peanut butter and banana sandwiches during a particularly stressful time period of her youth. It appeared that her immune system responded to this stressor with an overreaction to these two foods consumed during this time period and that it maintained this “memory” despite not being exposed to those foods for years. Such examples highlight the fact that we still have much to learn about allergy, the immune system and how stress and psychological factors play a role in the development of abnormal immune and allergic responses. This “conditioned response” to a substance (food, chemical or other) by the immune system from a psychologic or emotional stressor probably plays a far greater role than most of us realize, especially in the patient with multiple food and other environmental sensitivities.
8. Unsuspected Organs Involved
Some symptoms are simply not often thought of as possibly having an allergic origin. Patients with delayed food sensitivity symptoms such as headache, vertigo, gastrointestinal malfunction, mental dullness, depression, hyperactivity, or muscle/joint pain rarely suspect the true origin of their illness. Neither do their physicians who usually consider their illnesses “functional.”
People usually do not consider themselves allergic at all unless they also happen to have a disease commonly accepted as allergic, such as hay fever or asthma. Yet they may be experiencing symptoms almost every day due to food sensitivity in one or more organs not unusually considered involved in allergic reactions.
9. Food Addiction and Withdrawal Symptoms
A most difficult problem facing the patient who is trying to fit together the jigsaw of their puzzling illness is the phenomenon of masking. This is the situation in which the patient feels better immediately after eating an allergenic food, and worse later.
They often learn, consciously or unconsciously, to eat that particular food repeatedly at whatever interval of time is required in their case to keep them feeling relatively well. It is primarily when they postpone or miss a meal or snack of this food that they develop symptoms.
The first sensation produced by eating the masking food is often a pleasant, mild stimulation or relaxation accompanied by a feeling of well-being, extra energy, increased mental sharpness, self-confidence, exhilaration, or creativity. If the food is not eaten repeatedly, this may give way to the delayed symptoms, often including central nervous system depression.
During the stimulatory phase, he may tend to be energetic, positive, extroverted, gregarious, witty and friendly; whereas during the depressive phase, he may feel tired negative, introverted, inadequate, frightened, isolated, lonely, irritable, hostile, or even aggressive. Like Dr. Jekyll and Mr. Hyde, his mood and behavior can change rapidly from super-social to antisocial.
By eating the masking food often, regularly, and in fairly uniform quantities, the patient maintains the immediate positive effect. This holds off the delayed negative effect. In other words, he masks or overrides his depressive symptoms. He does not consider the food harmful, but rather beneficial. It is a favorite food because he feels so much better when he eats it. Interestingly, he also usually comes to consider it particularly tasty or delicious.
The masking patient does not usually note the immediate stimulation or at least does not consider it abnormal. In his estimation, this “high” is his normal state. If he stops the addicting food suddenly and entirely, he may have great central nervous system depression and a physical withdrawal reaction for one or more days, possibly with symptoms such as weakness, trembling, flushing, lethargy, fatigue, headache, imbalance, unsteady gait, join pains, slurred speech, tingling, or cold sweats. This may possibly cast suspicion on foods eaten on those days, but not likely on the one omitted.
Since at any time several masked foods may be causing either stimulatory or depressive symptoms of various types and degrees simultaneously, the patient is often caught in a maze of conflicting sensations. He may thus exhibit puzzling or volatile mood and behavioral swings which are beyond the understanding of himself and those around him.
10. Increased Tendency to Live on “Factory Foods” and Mixes
An additional difficulty in sorting out food problems has come from the complex, mixed, and chemicalized forms in which these foods are now usually eaten. Factory-processed foods make up an ever larger proportion of the modern diet. They are designed and prepared by chemists in factories rather that by cooks in kitchens. They are often erroneously called “health foods” and are highly promoted on television.
Some people live almost entirely on factory-processed foods. These often are mixtures containing a multitude of foods or food-derived ingredients, many of which may not be listed on the labels. Such foods often contain many synthetic and non-synthetic additives such as artificial colors, flavors, and preservatives, many of which are not discoverable even by an aware consumer.
Common Allergic Foods
It is important to note that ANY food or food substance can be the villain in a food sensitivity reaction. The foods we find to be the culprits in an individual food sensitive patient are most often those foods that are frequently and repetitively eaten by that person. Thus the 7 most common foods we see causing delayed reactions are the 7 most common foods eaten by today’s Americans. Keep in mind that we have observed significant sensitivity reactions to foods listed in the “rare” category and we have observed people with significant foods allergies actually tolerate some foods in the “most common” category. This point can be illustrated by an ulcerative colitis patient that was placed on a diet based on the “rare” food allergy category. Instead of improving, he actually became worse. Further evaluation revealed that he was sensitive to the very foods that were supposed to be “rare” and his “low antigenic food diet” was for him a “high allergic food diet”. It is for this reason, we recommend individualized testing whenever possible.
Based on our 20+ years of experience in food testing, we find the following:
Most Common (The Big 7): corn, eggs, milk (dairy), soy, sugar, wheat, yeast.
With the exception of milk (dairy) we find sugars and starches (grains) to be the most common allergic foods. This makes some sense when we realize that as mankind evolved these foods were the last to be introduced in our prehistoric diets and we therefore have had less time to learn to digest and assimilate them properly. Furthermore, today’s American diet incorporates far more starch and sugars than 100 or even 50 years ago.
Frequent: alcohol, apple, bacon, bean (dried), beef, berries, buckwheat, carrot, cheese, chocolate, cinnamon, coconut, coffee, fish, grape, mustard, nuts, onion, orange (citrus), peanut, peas, pork, potato, raisin, rye, shrimp, tomato
Occasional: alfalfa, amaranth, banana, barley (malt), celery, cherry, chicken, chiles, cloves, cottonseed, garlic, lettuce, lobster, melon, mushroom, oat, oysters, pear, peppers, pineapple, plums/prunes, quinoa, rice, sesame seed, spices, spinach, strawberry, sunflower, turkey, vinegar
Rare: apricot, beet, cranberry, honey, lamb, peach, rabbit, salmon, salt, squash, sweet potato, tapioca, taro root, tea, vanilla
Note: ANY vitamin, herb, or any other nutritional supplement, no matter how “good”, may be a reactive substance to some individuals. They all should be treated like a potential triggering agent in the food sensitive individual. We have countless examples where a person was sensitive to several different forms of a supplement (vitamin c, magnesium, etc) but diligent testing and rechallenge eventually uncovered a tolerable form of a recommended nutritional or herbal supplement.
Diagnosis of Food Sensitivity
The first step to determine your food sensitivities is usually the Elimination/Rechallenge Diagnosis Diet. This diagnostic diet is explained in detail in a separate monograph (click on the link) and in the appendix of the book It’s Only Natural by Drs. Poesnecker, Buttram and Kracht. The diet is based upon the elimination of the most common foods that cause sensitivity reactions and thus can be very helpful to the patient whose food sensitivities largely include these foods and food substances. For those with multiple other food sensitivities, this diagnostic diet may not be specific enough to provide useful information. Whenever we suspect food sensitivity playing a role in a person’s medical condition, we almost always recommend starting with the elimination/rechallenge diet. If this does not provide the answers we are looking for or if the diet cannot be performed for whatever reason, we can investigate the food sensitivity connection with skin testing or specialized blood tests.
Most hospital and regional laboratories can check an “IgE Food RAST” panel to several or many foods. It is most helpful in determining only “immediate” food reactions; this test does not help in evaluating delayed or hidden food sensitivity reactions. Because immediate food reactions are more identifiable, we utilize an IgE RAST for foods in the rare circumstance where there is a question of an immediate food allergy that cannot be answered by a careful history, a food challenge or skin testing.
There are other very specialized laboratories that can test for delayed type food reactions to a few or over 100 food and other items. These blood tests can be very helpful in evaluating a multitude of suspected or unsuspected foods all with a single blood draw. The two tests most frequently used by the our Center is the ALCAT and the ELISA/ACT. The limitations of these blood test are that they are expensive, they are roughly 70-80% accurate and the only treatment available after obtaining the results are eliminating the worst offending foods and rotating the mild and non-reactive foods on an every 3 or 4 day basis. This is quite easy if only a couple foods are found to be major reactors, but if many foods test positive, such elimination diets can be very difficult to follow and if one is not careful, they can be potentially nutrient deficient.
Another way we can test for food sensitivities is by skin testing. At Woodlands we prefer the Intradermal Progressive Food Titration (IDPFT) skin method to test and treat food allergies. This protocol was developed and is endorse by the American Academy of Otolarygolic Allergy. The advantage to using this type of food allergy testing and treatment is that it allows for a much more expanded diet. Furthermore, skin testing provides the necessary information to create very exact food sensitivity immunotherapy (allergy vaccine) treatment which offers the patient the luxury of tolerating their sensitive foods to a much greater extent. This allows for a much more “friendly” diet ensuring adequate nutritional intake. Our office is also able to screen for environmental chemicals and inhalant allergies that may cause similar symptoms. Please refer to our separate monograph on Allergy and Environmental Illness for a more detailed description of our allergy skin testing methods.
Other available, but far less studied, testing methods for food sensitivities include the electroaccupuncture (EAV) and kinesiologic (muscle testing) techniques. The Clymer Healing Research Center offers NAET kinesiology allergy testing and treatment. NAET can be used alone or in conjunction with Woodlands’ treatment.
Lastly, an indirect way of assessing the likelihood or possibility of food sensitivity is the Intestinal Permeability test. In this test, two sugar like substances (mannitol and lactulose) that are not normally absorbed by the intestines are given by mouth and afterwards a urine sample is taken. If these sugar type substances are found in the urine in larger amounts, it is evidence that the intestinal lining is allowing more substances to pass through suggestive that the field is ripe for food allergy or other problems. Although the intestinal permeability test in not specific for food allergy, we felt the discussion of food sensitivity testing would not be complete without it’s mention. If a “leaky gut” is found, targeted nutritional therapy can help it “heal and seal” thus greatly improving one’s food sensitivity symptoms by preventing them from being absorbed in the first place. A complete discussion of the leaky gut syndrome is beyond the scope of this article, please refer to our separate monograph for further information.
There is no one right way to test for food sensitivity. Each individual and each individual’s situation must be carefully evaluated to determine which type of test or tests are most helpful in uncovering this often hidden and masquerading medical condition of food allergy and sensitivity.
Treatment of Food Sensitivity
The cornerstone treatment for food allergy lies in avoidance, if and when possible. If a food causes a definite, immediate severe reaction (like peanuts causing severe asthma reaction) they should be permanently removed from the diet. On the other hand, most delayed type food reaction are not as “serious” or life threatening and if not removed from the diet just continue to contribute to the chronic symptoms and complaints previously mentioned (daily headaches, constant stuffy nose, etc). The more one can eliminate the strong offenders the better he or she will feel. Most authorities recommend complete avoidance of the major foods for 6 months with a trial of reintroduction after that time. While the serious offenders are eliminated, the rest of the foods in the diet (both mild to moderate food reactors and the nonreactors) are rotated. Rotation means that these foods are eaten only on an every 3 or 4 day basis. Some foods may need to be rotated on an every 7 day basis.
This treatment diet is called the Elimination/Rotation Diet. The results from the elimination/challenge diagnostic diet, blood tests, and/or skin testing can be utilized to make an individualized elimination/rotation treatment diet. It cannot be overemphasized that the single worst way that the food sensitive patient can live is by following a pattern of repetition. A varied diet is imperative in establishing and maintaining wellness. For more information on the details of this diet, refer to our separate monograph on this subject. If there are not too many major foods that need eliminated and one takes the time and effort to follow the rotation diet with the discipline required, this treatment method can be very successful in allowing the immune system to “recover and rebalance” itself and clear out some or all of those nagging, chronic symptoms that have been resistant to other forms of therapy.
Other aspects of the diet are also very important, especially the contamination of our foods with pesticides and other foods. As previously mentioned, we are of the strong opinion that these chemical contaminants play a large role in the development and continuation of food sensitivity. It is therefore, imperative to eat as much organic, pesticide and chemical free foods as is humanly possible given each individual’s circumstances.
Food Desensitization Immunotherapy (allergy vaccines as our patients like to call them) based on skin testing can be of tremendous benefit in treating both simple and complex food sensitivity conditions. By “neutralizing” the food sensitivity reactions, the person with multiple food sensitivities may need to eliminate only a few “major foods” and rotate others as best as circumstances permit. This food allergy immunotherapy is taken daily under the tongue or they can also be given as shots and allows a much more expanded diet. This is especially important for growing children and adults with marginal nutritional status. Sometimes treatment of other sensitivities, like pollens, grasses and chemicals, are required to obtain the most benefits from food desensitization immunotherapy.
If low stomach acid (hypochlorhydria) is identified or suspected, supplemental betaine HCL or herbal bitters may be helpful in aiding food digestion and breakdown in the stomach. If poor or weak pancreatic function is suspected or discovered digestive enzymes may be helpful in properly digesting and breaking down the food ingested in an attempt to prevent absorption of large food molecules that would more likely trigger an immune system response. If a “leaky gut” is discovered, its cause eliminated, and targeted nutritional therapy given to heal the intestinal lining, one can go a long way in obtaining additional benefits and results. If an intestinal dysbiosis condition exists (overgrowth of bacteria, yeast or parasites in the intestinal tract), targeted treatment will facilitate the intestinal lining and is often a critical step in treating food allergy.
Occasionally nutritional support of the immune system with antioxidants, vitamin c, selenium, zinc, B-complex and thymus extract is helpful. Quercitin (a bioflavonoid) has been shown to stabilize and prevent a certain type of immune system cell (mast cell) from releasing histamine and may offer some food sensitivity patients benefit by decreasing the immune system response to an exposed food antigen in the intestinal tract. Essential fatty acids like flax oil, fish oils, primrose oil, etc., have also been shown to decrease the inflammatory response and normalize an up regulated immune system that is over reacting to exposed substances. Metabolic and nutritional testing may be helpful in pinpointed deficiencies in these essential nutrients and aid in tailoring an individualized nutritional program for the food sensitive patient. Keep in mind, however, that any of these potentially helpful nutritional supplements may themselves be a trigger substance to a food sensitivity reaction in the susceptible individual.
Lastly, the role of stress and a “conditioned” immune and nervous system to react and over-react to environmental stimuli like foods, chemicals and other substances cannot be overstated. We feel it is vitally important to address this side of the neuro-immune system as well as the gastrointestinal side of the food allergy equation. Relaxation techniques, regular exercise, visualization, biofeedback, meditation, devotion, prayer and other similar “autogenic training” techniques all work to uncouple and “tone down” an up regulated, “hyper” immune and nervous system. Although the importance and relevance of these techniques and therapies are questioned by many, we see them work wonders on a daily basis. No matter what type of allergy or sensitivity is present, we urge you to incorporate one or more of these techniques into your everyday life; you will not be disappointed in the results.
Acute Food Sensitivity Reactions
For acute food sensitivity reactions, buffered vitamin C, alkali salts (baking soda, BiCarb Formula, Tri Salts, etc), histamine and heparin neutralizing drops, and other remedies can be used to decreased the severity of the resultant symptoms. Recommended doses are as follows:
- Buffered Vitamin C, 1000-2000 mg, taken as a powder or capsule form, every 15 to 30 minutes until the reaction clears. You may get loose stools or diarrhea if too much is taken, but otherwise, there is no harm in taking these dosage recommendations.
- Bicarb Formula or Tri Salts, 2-4 capsules or ½ tsp of the powder mixed in 4-8 oz of water every 15-30 minutes until the reaction clears. Children’s dose for age 3 or less is 1 capsule or 1/8 tsp, for ages 3-6 1 or 2 capsules or ¼ tsp. Alternatively, one can mix 1/4 tsp salt and 1/4 tsp baking soda in a 8 oz glass of water and take 2 to 4 ounces every 15-30 minutes as needed. Those with hypertension and heart failure should not take trisalts, BiCarb formula or baking soda unless directed by their physician.
- Food Allergy Neutralization Drops, if tested and on this type of treatment, these can also be used to treat acute food sensitivity reactions. They may be taken every 15 minutes until the reaction clears.
List of Food allergens
The big eight
The most common food allergies are:
- Dairy allergy
- Egg allergy
- Peanut allergy
- Tree nut allergy
- Seafood allergy
- Shellfish allergy
- Soy allergy
- Wheat allergy
These are often referred to as “the big eight.” They account for over 90% of the food allergies in the United States.
The top allergens vary somewhat from country to country but milk, eggs, peanuts, tree nuts, fish, shellfish, soy, wheat and sesame tend to be in the top 10 in many countries. Allergies to seeds – especially sesame – seem to be increasing in many countries.
More rare food allergies
Likelihood of allergy can increase with exposure. For example, rice allergy is more common in East Asia where rice forms a large part of the diet.
In Central Europe, celery allergy is more common. In Japan, allergy to buckwheat flour, used for Soba noodles, is more common.
Red meat allergy is extremely rare in the general population, but a geographic cluster of people allergic to red meat has been observed in Sydney, Australia. There appears to be a possible association between localised reaction to tick bite and the development of red meat allergy.
Fruit allergies exist, such as to apples, peaches, pears, jackfruit, strawberries, etc.
Corn allergy may also be prevalent in many populations, although it may be difficult to recognize in areas such as the United States and Canada where corn derivatives are common in the food supply.
Protein allergies are a common intolerance, especially among children, that are caused by seeds, nuts, meat, and milk.
The best method for diagnosing food allergy is to be assessed by an allergist. The allergist will review the patient’s history and the symptoms or reactions that have been noted after food ingestion. If the allergist feels the symptoms or reactions are consistent with food allergy, he/she will perform allergy tests.
Examples of allergy testing include:
- Skin prick testing is easy to do and results are available in minutes. Different allergists may use different devices for skin prick testing. Some use a “bifurcated needle”, which looks like a fork with 2 prongs. Others use a “multi-test”, which may look like a small board with several pins sticking out of it. In these tests, a tiny amount of the suspected allergen is put onto the skin or into a testing device, and the device is placed on the skin to prick, or break through, the top layer of skin. This puts a small amount of the allergen under the skin. A hive will form at any spot where the person is allergic. This test generally yields a positive or negative result. It is good for quickly learning if a person is allergic to a particular food or not, because it detects allergic antibodies known as IgE. Skin tests cannot predict if a reaction would occur or what kind of reaction might occur if a person ingests that particular allergen. They can however confirm an allergy in light of a patient’s history of reactions to a particular food. Non-IgE mediated allergies cannot be detected by this method.
- Blood tests are another useful diagnostic tool for evaluating IgE-mediated food allergies. For example, the RAST (RadioAllergoSorbent Test) detects the presence of IgE antibodies to a particular allergen. A CAP-RAST test is a specific type of RAST test with greater specificity: it can show the amount of IgE present to each allergen. Researchers have been able to determine “predictive values” for certain foods. These predictive values can be compared to the RAST blood test results. If a persons RAST score is higher than the predictive value for that food, then there is over a 95% chance the person will have an allergic reaction (limited to rash and anaphylaxis reactions) if they ingest that food. Currently, predictive values are available for the following foods: milk, egg, peanut, fish, soy, and wheat. Blood tests allow for hundreds of allergens to be screened from a single sample, and cover food allergies as well as inhalants. However, non-IgE mediated allergies cannot be detected by this method. Other widely promoted tests such as the antigen leukocyte cellular antibody test (ALCAT) and the Food Allergy Profile are considered unproven methods, the use of which is not advised.
- Food challenges, especially double-blind placebo-controlled food challenges (DBPCFC), are the gold standard for diagnosis of food allergies, including most non-IgE mediated reactions. Blind food challenges involve packaging the suspected allergen into a capsule, giving it to the patient, and observing the patient for signs or symptoms of an allergic reaction. Due to the risk of anaphylaxis, food challenges are usually conducted in a hospital environment in the presence of a doctor.
- Additional diagnostic tools for evaluation of eosinophilic or non-IgE mediated reactions include endoscopy, colonoscopy, and biopsy.
Important differential diagnosis are:
- Lactose intolerance; this generally develops later in life but can present in young patients in severe cases. This is due to an enzyme deficiency (lactase) and not allergy. It occurs in many non-Western people.
- Celiac disease; this is an autoimmune disorder triggered by gluten proteins such as gliadin (present in wheat, rye and barley). It is a non-IgE mediated food allergy by definition.
- Irritable bowel syndrome (IBS)
- C1 esterase inhibitor deficiency (hereditary angioedema); this rare disease generally causes attacks of angioedema, but can present solely with abdominal pain and occasional diarrhea.
Generally, introduction of allergens through the digestive tract is thought to induce immune tolerance. In individuals who are predisposed to developing allergies (atopic syndrome), the immune system produces IgE antibodies against protein epitopes on non-pathogenic substances, including dietary components. The IgE molecules are coated onto mast cells, which inhabit the mucosal lining of the digestive tract.
Upon ingesting an allergen, the IgE reacts with mast cells and tissue bound basophils to release a number of chemicals (including histamine) in a process called degranulation. This leads to oedema of the intestinal wall, loss of fluid and altered motility. The product is diarrhea.
Any food allergy has the potential to cause anaphylaxis, which in rare cases may be fatal.
The immune system’s eosinophils, once activated in a histamine reaction, will register any foreign proteins they see. One theory regarding the causes of food allergies focuses on proteins presented in the blood along with vaccines, which are designed to provoke an immune response. Influenza vaccines and the Yellow Fever vaccine are still egg-based, but the Measles-Mumps-Rubella vaccine stopped using eggs in 1994. However large scientific studies do not support this theory, especially as it applies to autoimmune disease.
Another theory focuses on whether an infant’s immune system is ready for complex proteins in a new food when it is first introduced.
One hypothesis at this time is the Hygiene hypothesis. While there is no proof for the hygiene hypothesis, people speculate that in modern, industrialized nations, such as the United States, food allergies are more common due to the lack of early exposure to dirt and germs, in part due to the over-use of antibiotics and antibiotic cleansers. This hypothesis is based partly on studies showing less allergy in third world countries. Some research suggests that the body, with less dirt and germs to fight off, turns on itself and attacks food proteins as if they were foreign invaders.
Antibiotics have also been implicated in Leaky Gut Syndrome which is another possible cause of food allergies
A lower incidence of food allergies in the developing world could also be due to differences in diet from the West and less exposure to food allergens.
Others have found that food allergies are due to widespread usage of baby skin-care products that contain allergens, such as lotions based upon peanut oil. These skin-care products are cheaper to manufacture than non-allergenic ones and using them sensitizes the baby, which later develops into a food allergy. This theory has yet to come with sufficient explanation as to why the occurrence of allergies has been on a steady rise in the last two decades.
According to a report issued by the American Academy of Pediatrics, “There is evidence that breastfeeding for at least 4 months, compared with feeding infants formula made with intact cow milk protein, prevents or delays the occurrence of atopic dermatitis, cow milk allergy, and wheezing in early childhood.” There is also a study going on in which they are introducing Peanuts to low-allergenic patients, and they gradually give amounts to the patient to try to make their body immune to reactions from the Peanuts. Only patients with low RAST on Peanuts should be enrolled. Anything above 0.35 on a RAST test is positive.
The mainstay of treatment for food allergy is avoidance of the foods that have been identified as allergens. For people who are extremely sensitive, this may involve the total avoidance of any exposure with the allergen, including touching or inhaling the problematic food as well as touching any surfaces that may have come into contact with it.
If the food is accidentally ingested and a systemic reaction (anaphylaxis) occurs, then epinephrine (best delivered with an autoinjector of epinephrine such as an Epipen or Twinject) should be used. It is possible that a second dose of epinephrine may be required for severe reactions. The patient should also seek medical care immediately.
Desensitisation is a cure for food allergies. If the major precipitating allergen is a pollen then this is targeted by current protocols for desensitisation, not the food analogue allergen. Injections are used as sublingual drops are not suitable for sufferers of oral allergy.
Prof. Dr. Ronald van Ree of The University of Amsterdam and The Academic Medical Center expects that vaccines can in theory be created using genetic engineering to cure allergies. If this can be done, food allergies could be eradicated in about ten years.
For reasons that are not entirely understood, the diagnosis of food allergies has apparently become more common in Western nations in recent times. In the United States food allergy affects as many as 5% of infants less than three years of age and 3% to 4% of adults. There is a similar prevalence in Canada.
The most common food allergens include peanuts, milk, eggs, tree nuts, fish, shellfish, soy, and wheat – these foods account for about 90% of all allergic reactions.
Various medical practitioners have a differing views on food allergies. Irritable Bowel Syndrome (IBS) patients have been studied with regards to food allergies. Some studies have reported on the role of food allergy in IBS; only one epidemiological study on functional dyspepsia and food allergy has been published. However, since 2005 several studies have demonstrated strong correlation between IgG and/or IgE food allergy and IBS symptoms The mechanisms by which food activates mucosal immune system are incompletely understood, but food specific IgE and IgG4 appeared to mediate the hypersensitivity reaction in a subgroup of IBS patients. Specific chemicals and receptors have been demonstrated to be critical in food allergy development in murine models. Exclusion diets based on skin prick test, RAST for IgE or IgG4, hypoallergic diet and clinical trials with oral disodium cromoglycate have been conducted, and some success has been reported in a subset of IBS patients.
Studies comparing skin prick testing and ELISA blood testing have found that the results of skin prick testing correlate poorly with symptoms of irritable bowel syndrome that correlate with food allergies demonstrated through ELISA testing and dietary challenge.
Extensive clinical experience has demonstrated significant improvement of patients with IBS whose ELISA-based food allergy testing is positive and where treatment includes a careful exclusion diet.
In addition, many practitioners of alternative medicine ascribe symptoms to food allergy where other doctors do not. The causal relationships between some of these conditions and food allergies have not been studied extensively enough to provide sufficient evidence to become authoritative. The interaction of histamine with the nervous system receptors has been demonstrated, but more study is needed. Other immune response effects are commonly known (swelling, irritation, etc.), but their relationships to some conditions has not been extensively studied. Examples are arthritis, fatigue, headaches, and hyperactivity. Nevertheless, hypoallergenic diets reportedly can be of benefit in these conditions, indicating that the current medical views on food allergy may be too narrow.
Milk and soy allergies in children can often go undiagnosed for many months, causing much worry for parents and health risks for infants and children. Many infants with milk and soy allergies can show signs of colic, blood in the stool, mucous in the stool, reflux, rashes and other harmful medical conditions. These conditions are often misdiagnosed as viruses or colic.
Some children who are allergic to cow’s milk protein also show a cross sensitivity to soy-based products. There are infant formulas in which the milk and soy proteins are degraded so when taken by an infant, their immune system does not recognize the allergen and they can safely consume the product. Hypoallergenic infant formulas can be based on hydrolyzed proteins, which are proteins partially predigested in a less antigenic form. Other formulas, based on free amino acids, are the least antigenic and provide complete nutrition support in severe forms of milk allergy.
Seventy-five percent of children who have allergies to milk protein are able to tolerate baked-in milk products, i.e., muffins, cookies, cake.
About 50% of children with allergies to milk, egg, soy, and wheat will outgrow their allergy by the age of 6. Those that don’t, and those that are still allergic by the age of 12 or so, have less than an 8% chance of outgrowing the allergy.
Peanut and tree nut allergies are less likely to be outgrown, although evidence now shows that about 20% of those with peanut allergies and 9% of those with tree nut allergies will outgrow their allergies. In such a case, they need to consume nuts in some regular fashion to maintain the non-allergic status.
Those with other food allergies may or may not outgrow their allergies.
In response to the risk that certain foods pose to those with food allergies, countries have responded by instituting labeling laws that require food products to clearly inform consumers if their products contain major allergens or by-products of major allergens.
United States law
Under the Food Allergen Labeling and Consumer Protection Act of 2004 (Public Law 108-282), companies are required to disclose on the label whether the product contains a major food allergen in clear, plain language. The allergens have to clearly be called out in the ingredient statement. Most companies list allergens in a statement separate from the ingredient statement.
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