A classic food allergy occurs when the bodyâ€™s immune system responds to otherwise benign proteins (allergens) as though they threatened the health and integrity of the system. In a classic reaction, the immune system attempts to counter the food allergens by stimulating IgE and IgG antibodies. When these antibodies react with the allergen, histamine and other chemicals (mediators) are released.
Type 1 Reactions
You know when you have one because your body suffers a notable and almost instant reaction such as itching, swelling, hives, and breathing difficulties. While most food allergies are mild, in some cases, they can cause anaphylactic shock. Because this type of reaction can be life threatening, this type of food allergy must be taken seriously. Approximately 5% of children younger than age 3 have Type 1 food allergies. According to the National Institute of Allergy and Infectious diseases, fewer than 2%â€”about 4 million Americansâ€”have Type 1 food allergies.
Type 2 Reactions
The majority of food allergy reactions are Type 2 reactions. These are not immediate, making them almost impossible to detect without sophisticated testing. Different foods break down at different rates, causing symptoms anywhere from 24-72 hours after ingestion, depending on the food and your unique body chemistry. Because of the delay in onset of symptoms it is often difficult to associate the use of food with reactive symptoms. Unfortunately, the foods that cause this toxic shock vary widely according to your individual susceptibility. Perfectly healthy foods can cause a variety of symptoms that can affect any organ system in your body. This type of reaction is far more common than many people believe. Many allergists believe that only a few people have food allergies. A 23 year ongoing study reveals that 95% of the population has this Type 2 toxic reaction to common everyday foods that you eat regularly.
Another source of adverse reactions to food are caused by nonimmulogic mediated mechanisms. Also called food intolerance or food hypersensitivity, adverse food reactions can occur because a person lacks the enzymes needed for proper digestion, such as for the lactose in milk, or has a sensitivity to such common preservatives, colorings and additives such as monosodium glutamate (MSG), sulfites, and gluten. Some adverse reactions are caused by food-borne microbial pathogens and toxins.
Signs and Symptoms
Clinically, the digestive system, the immune system, the cardiovascular system and the nervous system are the most frequently affected. Common clinical dysfunctions include cramps, constipation, diarrhea, hemorrhoids, Crohnâ€™s disease, colitis, congestion, inflammation, fatigue, hyperactivity, anxiety and depression. The weakest link in an individualâ€™s system is often the first to show a sign of dysfunction.
Physical assessment includes noting characteristic symptoms, signs, and pattern of reaction, as well as a history of past exposures and reactions to related foods.
There are several tests that help in the diagnosis of food reactivity. They all have there advantages and disadvantages. Unfortunately, there is no one simple, !00% reliable, inexpensive test available for food sensitivity testing. This is because no one test can measure all types of food reactions mentioned above. What we look for is a test that can give the most reliable information, which if followed, will lead to significant improvement in health.
The skin tests performed by allergists are for IgE Type 1 reactions are give no useful information for IgG Type 2 reactions.
In our office we test primarily for Type 2 food allergies because most people already know their Type 1 reactions. We use a Type 2 food allergy test that is highly scientific, accurate, and reproducible, having been meticulously developed over the past 20 years.
Other Diagnostic Procedures
This is considered the â€œgold standardâ€ for diagnosis. It involves an elimination or oligoantigenic (few foods which do not commonly cause sensitivity reactions) diet followed by re-introduction of foods one at a time until there is a return of a symptom. The food is then avoided again, re-introduced again and if the same symptom returns you can assume you have identified the sensitizing food.. This must not be done if there is any reason to suspect an anaphylactic reaction. The test can become confusing when combinations of foods are the problem.
Challenge or provocative testing
This involves placing food extracts under the tongue or injecting them under the skin. However, this test tends to be expensive and unreliable. Provoking symptoms is not advised for patients who have experienced anaphylactic reactions to foods, insect stings, or medications.
Enzyme Linked Serum Assay (ELISA)
This correlates well with RAST but is less expensive. ELISA IgG & ELISA IgG4 measures IgG & IgG4 respectively.
ELISA/ACT (Enzyme enhanced Lymphocyte Blastogenesis Assay/Advanced Cell Test)
This test is said to give virtually no false-positives and less than .2% false negatives. It will measure delayed hypersensitivity reactions, requires a 12 hour fast and then a blood draw. The test must be performed within 72 hours of drawing the blood, assuming sample is stored between 10-30 C in all-plastic container. If you are using steroids, they must be stopped 4 days before the test; aspirin and antihistamines must be stopped 2 days before the test. This test is also expensive.
With this test, the antigen (food) is put under the patientâ€™s tongue and the patientâ€™s reactions are observed: wheezing, pallor, fainting etc. The patientâ€™s subjective symptoms are recorded simultaneously. There are many false positive reactions. It is a cross between homeopathy and conventional allergy, using very small doses to try and induce a reaction. This test seems to produce the most inconsistent results. There are several negative studies including ones which showed fewer reactions to corn than distilled water and objective changes found in patients using distilled water.
This testing involves both diagnosis and therapeutic aspects. Different concentrations of each antigen (food) are injected beneath the skin. One then observes whether there is a wheal/flare reaction (similar to what many people get when bitten by an insect such as a mosquito). The neutralization dose is the strongest dilution of antigen which does not produce a wheal/flare reaction. A study that was done in an attempt to disprove this idea , but it was found that it does work.
Scratch, Skin testing
This is used by conventional allergists. There are many false positives and false negatives. It measures only IgE mediated reactions which cause the release of substances, especially histamine (hence the use of antihistamines for many allergic patients). The histamines cause vasodilation, an increased capillary permeability resulting in a wheal and flare reaction within 15 minutes or so. With inhalants, skin testing gives fair results but with food it gives very poor results. A clinically significant response cannot be diagnosed by the presence of a positive serological or skin prick test alone, neither can the diagnosis be invalidated by their absence. Even when the food allergy is of the immediate type, skin prick test and measurement of allergen specific IgE may be negative. The test is painful and time consuming and not useful in young children. In addition, the test is influenced by drugs such as antihistamines and steroids.
Used by many chiropractors, the food is placed on the patient and certain muscles are tested for strength and weakness. This test is inexpensive, fast, and gives immediate results. As yet, there are no â€œscientific studiesâ€, but it definitely does work for some people.
Dâ€™Adamo Blood Type
Dr. James Dâ€™Adamo has developed diets and exercise programs for each of the four different blood types (O, A, B, AB). It is based on research that certain diseases are more common among one blood group over another and his own clinical experience. People with type O blood seem to do better if they consume flesh protein and do a lot of physical activity. Type A blood type people are primarily creative and do better with low energy food and light exercise such as yoga. They are suited to be vegetarians. Type B people are a balance between typeâ€™s O and A. They are both practical and mental and can eat from a balance of both the animal and vegetable kingdom with a mix of light exercise and more vigorous activity. Type AB are somewhere between type A and B but are often towards one type or the other and therefore some are best suited for type A diet/exercise and others are better suited towards type B characteristics. For a complete discussion of this type of evaluation read Dr. Dâ€™Adamoâ€™s book, The Dâ€™Adamo Diet.
Electro-acupuncture according to Voll (EAV) testing
In a controlled, comparative study performed by Julia Tsuei M.D., F.A.C.O.G. between RAST, RASP, scratch, cytotoxic, food challenge and electro-acupuncture according to Voll (EAV) methods of allergy testing, EAV test results proved to be accurate and reproducible. There was a high degree of compatibility of the EAV with the other 5 tests, especially the food challenge test which is considered to be the most sensitive of the currently available tests. The study demonstrated great sensitivity.
Treatment Options Treatment Strategy
Managing food allergens or sensitivities usually means avoiding offending foods and treating symptoms when they occur. Naturopathic physicians are particularly skilled in guiding patients so that reactions are minimized, thus avoiding unnecessary food restrictions. Usually, once the food is eliminated from the diet, symptoms will abate. However, avoidance takes persistence and may not always be possible. For example, the substance may be present as an unspecified additive within another food or â€œhiddenâ€ in another form. Other factors such as the amount of the food, which parts of the food are used, or the way in which it is prepared can influence the systemic response. Therefore, treatment may be necessary to address occasional allergic symptoms.
- Antihistamines â€“Â for mild itching, swelling, rash, runny nose, or headache; available both by prescription and over the counter in many cold, sinus, and allergy remedies. These include diphenhydramine (Benadryl), clemastine (Tavist), chlorpheniramine (Chlor-Trimeton), loratadine (Claritin), and astemizole (Hismanal). Possible side effects include drowsiness, irritability, dry mouth, and heart palpitations. Hismanal when used with erythromycin, clarithromycin, and antifungal medications such as Nizoral and Sporanox can cause irregular heartbeat, fainting, dizziness, and, rarely, cardiac arrest and death.
- Antispasmodics â€“ such as hyoscyamine (Levsin, Anaspaz) for diarrhea, nausea, abdominal bloating, and cramping.
- Adrenaline (epinephrine injection) â€“Â for anaphylactic shock.
Complementary and Alternative Therapies
The key to treatment of food allergy is complete avoidance of allergens for four to six months. Reducing inflammation, minimizing hypersensitivity reactions, and restoring the integrity of the digestive tract are ways in which alternative therapies may help resolve food allergies. Hypersensitivity reactions may be associated with stress and anxiety. Mind-body techniques such as meditation, tai chi, yoga, and stress management may help normalize immune function.
Note: Lower doses are for children.
- Eliminate all food allergens from the diet. The most common allergenic foods are dairy, soy, citrus, peanuts, wheat, fish, eggs, corn, chocolate, and tomatoes.
- An elimination/challenge trial may be helpful in uncovering sensitivities. Remove suspected allergens from the diet for two weeks. Re-introduce foods at the rate of one food every three days. Watch for reactions which may include gastrointestinal upset, mood changes, headaches, and exacerbation of symptoms. Do not perform a challenge with peanuts if there is history of anaphylaxis.
- A rotation diet, in which the same food is not eaten more than once every four days, may be helpful in minimizing food allergies.
- Reduce pro-inflammatory foods in the diet including saturated fats (meats, especially poultry, and dairy), refined foods, and sugar. For those with sensitivities to antibiotics it is essential to eat only organic meats to avoid antibiotic residues.
- Increase intake of fresh vegetables, whole grains, and essential fatty acids (cold-water fish, nuts, and seeds).
- Flaxseed, borage, or evening primrose oil (1,000 to 1,500 mg one to two times/day) are anti-inflammatory. Children should be supplemented with cod liver oil (1/2 to 1 tsp./day).
- Zinc (10 to 30 mg/day) and beta-carotene (25,000 to 50,000 IU/day) support immune function and encourage healing of mucosal tissues.
- Vitamin C (250 to 1,000 mg bid to qid) inhibits histamine release. Vitamin C from rose hips or palmitate is citrus-free and hypoallergenic.
- B-complex vitamins (25 to 100 mg/day) help to reduce the effects of stress and normalize immune function.
- Selenium (50 to 200 mcg/day) helps to regulate fatty acid metabolism and is a co-factor in liver detoxification.
- Bromelain (100 to 250 mg between meals) is a proteolytic enzyme that decreases inflammation.
- Pancreatin (8X USP) one to two tablets with meals to enhance digestion.
- Pro-flora supplements (one to three capsules/day) can help to normalize bowel flora.
Herbs are generally a safe way to strengthen and tone the bodyâ€™s systems. As with any therapy, it is important to ascertain a diagnosis before pursuing treatment. Herbs may be used as dried extracts (capsules, powders, teas), glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless otherwise indicated, teas should be made with 1 tsp. herb per cup of hot water. Steep covered 5 to 10 minutes for leaf or flowers, and 10 to 20 minutes for roots. Drink 2 to 4 cups/day. Tinctures may be used singly or in combination as noted.
- Quercetin (100 to 250 mg tid before meals) minimizes reactions to food.
- Rose hips (Rosa canina) tea is anti-inflammatory, high in hypoallergenic vitamin C, and healing to the digestive tract. Drink three to four cups/day, four ounces tid to qid for children. This is particularly effective for children.
- Marshmallow root tea (Althea officinalis) may soothe and promote healing of gastrointestinal inflammation. Soak one heaping tbsp. of marshmallow root in one quart of cold water overnight. Strain and drink throughout the day.
- Dandelion (Taraxacum officinale), milk thistle (Silybum marianum), celandine (Chelidonium majus), and chicory (Cichorium intybus) stimulate liver function.
- Soothing carminative herbs will enhance digestion and reduce spasm. Choose three or more of the following to make a tea to sip before meals. Chamomile (Matricaria recutita), peppermint (Mentha piperita), passionflower (Passiflora incarnata), meadowsweet (Filependula ulmaria), fennel (Foeniculum vulgare), and catnip (Nepeta cataria).
An experienced homeopath should assess individual constitutional types and severity of disease to select the correct remedy and potency.
Acupuncture may help restore normal immune function and reduce the hypersensitivity response.
Therapeutic massage may help reduce the effects of stress.
A diet based on vegetables, fruits, and high-fiber foods and one that is also low in fat and refined sugar is considered best when addressing any type of allergy. Because there seems to be a connection between the inflammatory process and animal fat, it may help to reduce consumption of animal products.
Conservative introduction of solid foods as child is weaning may help prevent hypersensitivity conditions. If there is a strong family history of allergies or atopic conditions and/or if the childâ€™s immunity has been compromised in infancy, delay the introduction of highly allergenic foods until one year or older.
Some research suggests a link between food allergies and celiac disease, arthritis, chronic infection, depression, anxiety, and chronic fatigue.
Most infants outgrow their Type 1 sensitivities to food by 2 to 4 years. Adults with food allergies tend to retain them for years. While there is no cure for food allergies, prognosis for remaining symptom-free is excellent as long as offending foods are identified and avoided and the digestive system and immune system is treated.
Nutritional support may safely relieve symptoms during pregnancy.