Food Allergy: A Look at Traditional and Complementary Diagnosis and Treatment
By Carol M. Meerschaert, RD
Vol. 9 No. 7 P. 40
When my daughter Sarah was 4 years old, we visited Ocean Spray Cranberry World in Massachusetts, where she enjoyed at least a dozen small glasses of cranberry beverages. We learned about cranberry bogs and cranberry rakes. We also learned what hives look
like, as my daughter asked me how so many mosquitoes could have bitten her because she itched all over. Thankfully, my mother, who raised eight children, was there and gave the grandmotherly diagnosis of hives.
What could have caused my daughter’s hives? We figured it was cranberries due to the excessive intake that day and because there was not another new food or potential allergen that she had been exposed to for the first time that day.
In the 15 years since that day, Sarah has avoided cranberries in all forms and all red punch, just in case it is made with cranberries. But is she truly allergic to cranberries?
I’ve related this story because when researching the literature and hearing reports of treatments for food allergies, the first question the wise nutrition professional must ask is: Did the person treated for or cured of the food allergy actually have the food allergy to begin with?
Approximately one fourth of American households modify their dietary habits because at least one member of the household is thought to have a food allergy or intolerance.1 Studies show that parents believe 28% to 43% of children under the age of 3 have food allergies.1 Contrast the self-proclaimed incidence of allergies with the scientific studies that report 1.5% to 2% of the general population and 5% to 7% of young children have a food allergy.
It may be easy to avoid cranberries, but it may not be easy to avoid food ubiquitous in the American diet such as dairy and wheat.2 Not only is food purchasing and preparation altered, but Bollinger et al found that 60% of families who had children with food allergies believed a child’s food allergies significantly affected family social activities.2 More than one third said food allergies had adversely affected school attendance, and 10% stated that they homeschool their children because of food allergies.
A study from the journal Pediatric Allergy and Immunology found that one quarter of previously allergic patients continued to avoid eating a food after they found that they did not react to that food in a food challenge.3 Neither the severity of the initial reaction nor a prolonged avoidance diet influenced the decision not to reintroduce the food. This is unfortunate because people who reintroduced the food reported that their social life generally improved.
A 2003 study of the quality-of-life status of children with a peanut allergy found that these children lived in fear of other adverse health effects, restricted their physical activity, and worried about being away from home even more than children with diabetes.4 These studies underline the importance of an accurate food allergy diagnosis and implore nutrition professionals to question self-diagnosis of food allergies and intolerances, especially in children.
Diagnosing Food Allergy
Every Today’s Dietitian reader knows that the “gold standard” for food allergy diagnosis is the double-blind placebo-controlled study. Most insurance companies will cover this testing. To find a specialist to perform this service for your clients, search on the American Board of Medical Specialties Web site (www.abms.org) for a physician who has earned board certification from the American Board of Allergy and Immunology (www.abai.org). Along with the double-blind challenge tests, the other most commonly used valid testing method for diagnosis of food allergies is a skin prick test using extracts of the food. Nutrition professionals should be aware that many “food allergies” are diagnosed by methods without scientific merit.
The diagnosis of food allergies by using a radioallergosorbent test (RAST) to identify food-specific immunoglobulin E (IgE) antibodies is a proven, science-based technique. However, the production of IgG and IgA in response to food is normal. Thus, the presence of these antibodies to food does not indicate a food allergy.5 This fact is often overlooked, and a practitioner may diagnose a food allergy simply because the person has a normal immune system.
Another testing technique is the provocation-neutralization technique, which can involve a sublingual or intradermal provocation, meaning that a bit of the suspected food is placed under the tongue or injected into the patient. The patient is observed for 10 minutes, and the response is measured. In the neutralization portion, the patient is given a smaller dose of the allergen, and this is repeated until the “allergy” is neutralized. This neutralization dose is repeated to desensitize the patient. This technique was not scientifically validated in two blinded control studies conducted by Jewett et al and Fox et al.6,7 The American Academy of Allergy Asthma & Immunology has concluded that the provocation-neutralization method is ineffective and lacks immunological rationale.8
There is a more conventional food allergy therapy called specific oral tolerance induction (SOTI) in which very low doses of the food that a person is allergic to are given, gradually increasing the daily dose up to an amount equivalent to a usually relevant dose for daily intake followed by a daily maintenance dose. A report in the journal Allergy stated that the body of scientific evidence concerning SOTI is poor.9 The scientific literature contains only a couple case reports on a limited number of patients. So far, no placebo-controlled, long-term study has been published. This may be a technique for the future, after further research is conducted.
Another “test” for food allergy is applied kinesiology. This involves the subjective manual measurement of muscle strength.10 The patient holds the suspected food, often inside a glass bottle, in one hand while the investigator estimates muscle strength in the other hand. There is no scientific proof for this technique, according to the 1999 position paper on adverse reactions to food published in Allergy.8
These unproven diagnostic techniques are commonly used. A survey of 380 families with children with multiple food allergies found that 22% of them used diagnostic modalities considered unproven or disproven (such as serum IgG4, electrodermal skin testing, and kinesiology).11
A further complication of the issue of food allergies is that often people “lose” their food allergies. The prevalence of food allergies in infants and young children is three to five times as high as in adults. The majority of children (85%) with food allergies lose their sensitivity to the offending food by the ages of 3 to 5. “We don’t know why children can outgrow an allergy or why an adult who was once allergic to a food no longer is allergic,” says Andrew Carey, MD, a board-certified allergist at Adult and Pediatric Allergy and Asthma Treatment Centers in Lewiston and Falmouth, Me.
When clients report that they were cured of a food allergy, was it from a spontaneous remission or because of a conventional or complementary therapy?
Acupuncture has been reported to treat allergies. However, Li and Srivastava noted in their review of traditional Chinese medicine for the therapy of allergic disorders that food allergy is not a disorder usually recognized in traditional Chinese medicine literature.12 There are many studies that examine the use of acupuncture in asthma. In a review of these studies, Kleijnen found 13 controlled studies where four of the studies were negative and six were positive in treating asthma.13 The conclusion was that benefits were more likely to be found in low-quality studies. Cochrane Reviews examined 11 studies; however, most were judged to be of poor quality.14 Of those that were high quality (randomized, controlled, and blinded), the effects of acupuncture were not different from placebo. Acupuncture has been reported to be effective in treating hives, though.15
Homeopathy is based on the belief that symptoms of a disease can be cured by the same substance that provoked the illness, if given in ultra-small doses. When randomized, placebo-controlled studies were performed to test homeopathy on environmental allergies, there was no clinical benefit to using homeopathy to treat allergies.16 There have been no studies conducted to examine the effect on food allergy.16
Many pharmaceuticals are based on plants, so it is not surprising to find herbal treatments for diseases and conditions—including allergies. “Aspirin is derived from willow bark,” says Carey. “Willow bark has been shown to be therapeutic in a select group of patients with sinusitis.” Carey notes that you would need to run tests to determine whether a given patient falls into the category of people for which this is a treatment. “Aspirin or willow bark will not help in most people with sinusitis,” he explains. “It only helps in those with increased CysLT1 [cysteinyl leukotriene receptor 1] receptors on their leukocytes.”
Other herbal preparations have been suggested for treating allergies, but Carey cautions that herbal preparations, especially those imported from other countries, may contain pharmaceuticals. “A study we did in San Diego found that herbs our patients brought in from Mexico did help their asthma and allergies. This was not because of the effect of the herbs but because the herbs had prednisone added,” he says.
Some supplements may be useful in the prevention or treatment of food allergy. Probiotics are supplements of beneficial bacteria such as Lactobacillus and Bifidobacteria. Furrie wrote a review reporting that the use of probiotic therapy to prevent allergic disease has been demonstrated in two studies using Lactobacillus rhamnosus GG in newborn children.17 Management of allergy through probiotics has also been demonstrated in infants, using lactobacilli to control atopic eczema and cow’s milk allergy. Unfortunately, these positive results have not been repeated in studies with older children and young adults.17
A review paper written by Laitinen and Isolauri states that probiotics have been shown to reverse the increased intestinal permeability characteristic of children with food allergy and enhance specific IgA responses frequently defective in children with food allergy.18 Probiotics appear to work by providing maturational signals for the gut-associated lymphoid tissue and by balancing the generation of proinflammatory and anti-inflammatory cytokines.
Dietary fat intake may play a role in atopic disease such as eczema. Typical American diets contain almost 10 times more linoleic acid (18:2 omega-6) than alpha-linolenic acid (18:3 omega-3). This leads to the production of arachidonic acid-derived eicosanoids that alter the balance of T-helper cells types 1 and 2, thus favoring the production of IgE. Dietary omega-3 fatty acids can have a marked influence on specific and nonspecific immune responses in modifying eicosanoid production and replacing omega-6 fatty acids in cell membranes.18 It is then thought that increasing the consumption of omega-3 fats from sources such as supplements, fish and fish oil, and walnuts may assist in the treatment of atopic diseases. It is appropriate to expand this to the treatment of food allergies.
The only proven way to treat a food allergy is to avoid eating the food. Dietitians should be sure that clients seeking a food elimination diet have been tested for the food allergy by proven scientific methods so that they do not carry an unnecessary burden by restricting their diets. Furthermore, because food allergies are not necessarily life-long conditions, patients who find avoiding a food troublesome should also be strongly encouraged to seek a board-certified allergist for testing. They may come to your counseling practice asking you to show them how to avoid a long list of foods. If you help them discover that they are not allergic to some foods, your clients could exit your practice not only eating a much larger variety of foods but also having a better, less stressful life. That is a job well done.
— Carol M. Meerschaert, RD, is a freelance writer, a corporate consultant, and a lecturer in Falmouth, Me. You can reach her at firstname.lastname@example.org.
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