Elimination diet

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An elimination diet, also known as exclusion diet, is a diagnostic procedure used to identify foods that an individual cannot consume without adverse effects. [1] Adverse effects may be due to food allergy, food intolerance, other physiological mechanisms (such as metabolic or toxins), [2] or a combination of these. Elimination diets typically involve entirely removing a suspected food from the diet for a period of time from two weeks to two months, and waiting to determine whether symptoms resolve during that time period. In rare cases, a health professional may wish to use an elimination diet, also referred to as an oligoantigenic diet, to relieve a patient of symptoms they are experiencing. [3]

Contents

Common reasons for undertaking an elimination diet include suspected food allergies and suspected food intolerances. An elimination diet might remove one or more common foods, such as eggs or milk, or it might remove one or more minor or non-nutritive substances, such as artificial food colorings.

An elimination diet relies on trial and error to identify specific allergies and intolerances. Typically, if symptoms resolve after the removal of a food from the diet, then the food is reintroduced to see whether the symptoms reappear. This challenge–dechallenge–rechallenge approach has been claimed to be particularly useful in cases[ clarification needed ] with intermittent or vague symptoms. [4]

The exclusion diet can be a diagnostic tool or method used temporarily to determine whether a patient's symptoms are food-related. The term elimination diet is also used to describe a "treatment diet", which eliminates certain foods for a patient. [2] [5] [6]

Adverse reactions to food can be due to several mechanisms. Correct identification of the type of reaction in an individual is important, as different approaches to management may be required. The area of food allergies and intolerances has been controversial and is currently a topic that is heavily researched. It has been characterised in the past by lack of universal acceptance of definitions, diagnosis and treatment. [2] [7]

History

The concept of the elimination diet was first proposed by Dr. Albert Rowe in 1926 and expounded upon in his book, Elimination Diets and the Patient's Allergies, published in 1941. [8]

In 1978 Australian researchers published details of an 'exclusion diet' to exclude specific food chemicals from the diet of patients. This provided a basis for challenge with these additives and natural chemicals. Using this approach, the role played by dietary chemical factors in the pathogenesis of chronic idiopathic urticaria (CIU) was first established and set the stage for future DBPCT trials of such substances in food intolerance studies. [9] [10]

Definitions

"Food hypersensitivity" is an umbrella term which includes food allergy and food intolerance. [11] [12] [13]

Food allergy is defined as an immunological hypersensitivity which occurs most commonly to food proteins such as egg, milk, seafood, shellfish, tree nuts, soya, wheat and peanuts. Its biological response mechanism is characterized by an increased production of IgE (immunoglobulin E) antibodies. [14]

A food intolerance on the other hand does not activate the individual's immune response system. A food intolerance differs from a food allergy or chemical sensitivity because it generally requires a normal serving size to produce symptoms similar to an IgE immunologic response. While food intolerances may be mistaken for a food allergy, they are thought to originate in the gastrointestinal system. Food intolerances are usually caused by the individual's inability to digest or absorb foods or food components in the intestinal tract. [14] One common example of food intolerance is lactose intolerance.

Elimination diets are useful to assist in the diagnosis of food allergy and pharmacological food intolerance. Metabolic, toxic and psychological reactions should be diagnosed by other means. [2] [20] [21]

Diagnosis

Food allergy is principally diagnosed by careful history and examination. When reactions occur immediately after certain food ingestion then diagnosis is straight forward and can be documented by using carefully performed tests such as the skin prick test (SPT) and the radioallergosorbent test RAST to detect specific IgE antibodies to specific food proteins and aero-allergens. However, false positive results occur when using the SPT when diagnosis of a particular food allergen is hard to determine. This can be confirmed by exclusion of the suspected food or allergen from the patient's diet. It is then followed by an appropriately timed challenge under careful medical supervision. If there is no change of symptoms after 2 to 4 weeks of avoidance of the protein then food allergy is unlikely to be the cause and other causes such as food intolerance should be investigated. [21] [22] [23] This method of exclusion-challenge testing is the premise by which the Elimination Diet is built upon, as explained in the sections below.

Vega machine testing, a bioelectric test, is a controversial method that attempt to measure allergies or food or environmental intolerances. Currently this test has not been shown to be an effective measure of an allergy or intolerance. [24]

Food intolerance due to pharmacological reaction is more common than food allergy and has been estimated to occur in 10% of the population. Unlike a food allergy, a food intolerance can occur in non-atopic individuals. Food intolerances are more difficult to diagnose since individual food chemicals are widespread and can occur across a range of foods. Elimination of these foods one at a time would be unhelpful in diagnosing the sensitivity. Natural chemicals such as benzoates and salicylates found in food are identical to artificial additives in food processing and can provoke the same response. Since a specific component is not readily known and the reactions are often delayed up to 48 hours after ingestion, it can be difficult to identify suspect foods. In addition, chemicals often exhibit dose-response relationships and so the food may not trigger the same response each time. There is currently no skin or blood test available to identify the offending chemical(s), and consequently, elimination diets aimed at identifying food intolerances need to be carefully designed. All patients with suspected food intolerance should consult a physician first to eliminate other possible causes. [2] [20]

The elimination diet must be comprehensive and should contain only those foods unlikely to provoke a reaction in a patient. They also need to be able to provide complete nutrition and energy for the weeks it will be conducted. Professional nutritional advice from a dietitian or nutritionist is strongly recommended. Thorough education about the elimination diet is essential to ensure patients and the parents of children with suspected food intolerance understand the importance of complete adherence to the diet, as inadvertent consumption of an offending chemical can prevent resolution of symptoms and render challenge results useless.

While on the elimination diet, records are kept of all foods eaten, medications taken, and symptoms that the patient may be experiencing. Patients are advised that withdrawal symptoms can occur in the first weeks on the elimination diet and some patients may experience symptoms that are worse initially before settling down.

While on the diet some patients become sensitive to fumes and odours, which may also cause symptoms. They are advised to avoid such exposures as this can complicate the elimination and challenge procedures. Petroleum products, paints, cleaning agents, perfumes, smoke and pressure pack sprays are particular chemicals to avoid when participating in an elimination diet. Once the procedure is complete this sensitivity becomes less of a problem.

Clinical improvement usually occurs over a 2 to 4 week period; if there is no change after a strict adherence to the elimination diet and precipitating factors, then food intolerance is unlikely to be the cause. A normal diet can then be resumed by gradually introducing suspected and eliminated foods or chemical group of foods one at a time. Gradually increasing the amount up to high doses over 3 to 7 days to see if exacerbated reactions are provoked before permanently reintroducing that food to the diet. A strict elimination diet is not usually recommended during pregnancy, although a reduction in suspected foods that reduce symptoms can be helpful. [2]

Challenge testing

Challenge testing is not carried out until all symptoms have cleared or improved significantly for five days after a minimum period of two weeks on the elimination diet. The restrictions of the elimination diet are maintained throughout the challenge period. Open food challenges on wheat and milk can be carried out first, then followed by challenge periods with natural food chemicals, then with food additives. Challenges can take the form of purified food chemicals or with foods grouped according to food chemical. Purified food chemicals are used in double blind placebo controlled testing, and food challenges involve foods containing only one suspect food chemical eaten several times a day over 3 to 7 days. If a reaction occurs patients must wait until all symptoms subside completely and then wait a further 3 days (to overcome a refractory period) before recommencing challenges. Patients with a history of asthma, laryngeal oedema or anaphylaxis may be hospitalised as inpatients or attended in specialist clinics where resuscitation facilities are available for the testing.

If any results are doubtful the testing is repeated, only when all tests are completed is a treatment diet determined for the patient. The diet restricts only those compounds to which the patient has reacted and over time liberalisation is attempted. In some patients food allergy and food intolerance can coexist, with symptoms such as asthma, eczema and rhinitis. In such cases the elimination diet for food intolerance is used for dietary investigation. Any foods identified by SPT or RAST as suspect should not be included in the elimination diet. [2] [7] [20] [21] [22] [23] [25] [26] [27] [28] [29]

See also

Related Research Articles

<span class="mw-page-title-main">Allergy</span> Immune system response to a substance that most people tolerate well

Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Note that food intolerances and food poisoning are separate conditions.

Multiple chemical sensitivity (MCS), also known as idiopathic environmental intolerances (IEI), is an unrecognized and controversial diagnosis characterized by chronic symptoms attributed to exposure to low levels of commonly used chemicals. Symptoms are typically vague and non-specific. They may include fatigue, headaches, nausea, and dizziness.

<span class="mw-page-title-main">Food allergy</span> Hypersensitivity reaction to a food

A food allergy is an abnormal immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressure. This typically occurs within minutes to several hours of exposure. When the symptoms are severe, it is known as anaphylaxis. A food intolerance and food poisoning are separate conditions, not due to an immune response.

<span class="mw-page-title-main">Gluten-free diet</span> Diet excluding proteins found in wheat, barley, and rye

A gluten-free diet (GFD) is a nutritional plan that strictly excludes gluten, which is a mixture of prolamin proteins found in wheat, as well as barley, rye, and oats. The inclusion of oats in a gluten-free diet remains controversial, and may depend on the oat cultivar and the frequent cross-contamination with other gluten-containing cereals.

Food intolerance is a detrimental reaction, often delayed, to a food, beverage, food additive, or compound found in foods that produces symptoms in one or more body organs and systems, but generally refers to reactions other than food allergy. Food hypersensitivity is used to refer broadly to both food intolerances and food allergies.

<span class="mw-page-title-main">Aspirin-exacerbated respiratory disease</span> Chronic inflammatory disease affecting the sinuses and lungs

Aspirin-exacerbated respiratory disease (AERD), also called NSAID-exacerbated respiratory disease (N-ERD) or historically aspirin-induced asthma and Samter's Triad, is a chronic respiratory disease defined by the simultaneous presence of three factors: asthma, chronic rhinosinusitis with nasal polyps, and intolerance of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). In general, the nasal polyps are more recalcitrant and the asthma more severe than that of aspirin-tolerant patients. Reduction or loss of the ability to smell is extremely common, occurring in greater than 90% of AERD patients. AERD most commonly begins in early- to mid-adulthood and has no known cure. While NSAID intolerance is a defining feature of AERD, avoidance of NSAIDs does not prevent the onset, development or perennial nature of the disease.

<span class="mw-page-title-main">Peanut allergy</span> Type of food allergy caused by peanuts

Peanut allergy is a type of food allergy to peanuts. It is different from tree nut allergies, because peanuts are legumes and not true nuts. Physical symptoms of allergic reaction can include itchiness, hives, swelling, eczema, sneezing, asthma attack, abdominal pain, drop in blood pressure, diarrhea, and cardiac arrest. Anaphylaxis may occur. Those with a history of asthma are more likely to be severely affected.

<span class="mw-page-title-main">Soy allergy</span> Type of food allergy caused by soy

Soy allergy is a type of food allergy. It is a hypersensitivity to ingesting compounds in soy, causing an overreaction of the immune system, typically with physical symptoms, such as gastrointestinal discomfort, respiratory distress, or a skin reaction. Soy is among the eight most common foods inducing allergic reactions in children and adults. It has a prevalence of about 0.3% in the general population.

Oral allergy syndrome (OAS) or pollen-food allergy is a type of food allergy classified by a cluster of allergic reactions in the mouth and throat in response to eating certain fruits, nuts, and vegetables. It typically develops in adults with hay fever.

<span class="mw-page-title-main">Milk allergy</span> Type of food allergy caused by milk

Milk allergy is an adverse immune reaction to one or more proteins in cow's milk. Symptoms may take hours to days to manifest, with symptoms including atopic dermatitis, inflammation of the esophagus, enteropathy involving the small intestine and proctocolitis involving the rectum and colon. However, rapid anaphylaxis is possible, a potentially life-threatening condition that requires treatment with epinephrine, among other measures.

<span class="mw-page-title-main">Egg allergy</span> Type of food allergy caused by eggs

Egg allergy is an immune hypersensitivity to proteins found in chicken eggs, and possibly goose, duck, or turkey eggs. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus.

<span class="mw-page-title-main">Wheat allergy</span> Medical condition

Wheat allergy is an allergy to wheat which typically presents itself as a food allergy, but can also be a contact allergy resulting from occupational exposure. Like all allergies, wheat allergy involves immunoglobulin E and mast cell response. Typically the allergy is limited to the seed storage proteins of wheat. Some reactions are restricted to wheat proteins, while others can react across many varieties of seeds and other plant tissues. Wheat allergy is rare. Prevalence in adults was found to be 0.21% in a 2012 study in Japan.

<span class="mw-page-title-main">Salicylate sensitivity</span> Medical condition

Salicylate sensitivity is any adverse effect that occurs when a usual amount of salicylate is ingested. People with salicylate intolerance are unable to consume a normal amount of salicylate without adverse effects.

A drug allergy is an allergy to a drug, most commonly a medication, and is a form of adverse drug reaction. Medical attention should be sought immediately if an allergic reaction is suspected.

Perfume intolerance or perfume allergy is a condition wherein people exhibit sensitivity or allergic reactions to ingredients in some perfumes and some other fragrances. It is a form of multiple chemical sensitivity, a more general phenomenon for this diagnosis.

Non-celiac gluten sensitivity (NCGS) or gluten sensitivity is a controversial disorder which can cause both gastrointestinal and other problems.

<span class="mw-page-title-main">Allergies in cats</span>

Cats exposed to allergens may develop allergies or allergic reactions. Allergies tend to become evident and intensify over extended periods of time and can take years to develop. Some allergic diseases and allergies in cats include feline atopic dermatitis, flea allergy dermatitis, feline-mosquito hypersensitivity, and food-induced allergy. In the case of feline atopy, hypersensitivity to allergens is due to genetic predisposition. However, various allergies may arise due to environmental factors. Allergens, ingested, inhaled, or airborne, can be seasonal or non-seasonal, similar to allergies in humans. Suspected seasonal allergens include but are not limited to pollen, fleas, and mosquito bites; suspected non-seasonal allergens include but are not limited to plastic materials, food, dust, trees, and grass. After exposure to suspected allergens, symptoms may be immediate or delayed, arising within a few minutes to two hours. Symptoms can include both dermatological and gastrointestinal signs such as itchy skin, hair loss and excessive scratching. In cases of feline atopic dermatitis or atopy in cats, pruritic skin diseases may result; however, signs can also include miliary dermatitis, symmetrical alopecia, and lesions of the eosinophilic granuloma complex.

Candida hypersensitivity is a pseudoscientific syndrome promoted by William G. Crook, M.D. It is spuriously claimed that chronic yeast infections are responsible for many common disorders and non-specific symptoms including fatigue, weight gain, constipation, dizziness, muscle and joint pain, asthma, and others.

<span class="mw-page-title-main">Fish allergy</span> Type of food allergy caused by fish

Fish allergy is an immune hypersensitivity to proteins found in fish. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus. Fish is one of the eight common food allergens which are responsible for 90% of allergic reactions to foods: cow's milk, eggs, wheat, shellfish, peanuts, tree nuts, fish, and soy beans.

References

  1. ↑ "Allergies: Elimination Diet and Food Challenge Test". WebMD. Retrieved 2009-04-01.
  2. 1 2 3 4 5 6 7 Clarke L, McQueen J, Samild A, Swain AR (1996). "Dietitians Association of Australia review paper. The dietary management of food allergy and food intolerance in children and adults" (PDF). Aust J Nutr Dietetics. 53 (3): 89–98. ISSN   1032-1322. OCLC   20142084.
  3. ↑ Egger J, Carter CM, Wilson J, Turner MW, Soothill JF (October 1983). "Is migraine food allergy? A double-blind controlled trial of oligoantigenic diet treatment". Lancet. 2 (8355): 865–9. doi:10.1016/S0140-6736(83)90866-8. PMID   6137694. S2CID   33813933.
  4. ↑ Minford, A M; MacDonald, A; Littlewood, J M (October 1982). "Food intolerance and food allergy in children: a review of 68 cases". Arch Dis Child. 57 (10): 742–7. doi:10.1136/adc.57.10.742. PMC   1627921 . PMID   7138062.
  5. ↑ Laitinen K, Isolauri E (2007). "Allergic infants: growth and implications while on exclusion diets". Nestle Nutr Workshop Ser Pediatr Program. Nestlé Nutrition Workshop Series: Pediatric Program. 60: 157–67, discussion 167–9. doi:10.1159/000106367. ISBN   978-3-8055-8283-4. PMID   17664903.
  6. ↑ Barbi E, Berti I, Longo G (2008). "Food allergy: from the loss of tolerance induced by exclusion diets to specific oral tolerance induction". Recent Pat Inflamm Allergy Drug Discov. 2 (3): 212–4. doi:10.2174/187221308786241875. PMID   19076011. Archived from the original on 2013-04-14.
  7. 1 2 Allen DH, Van Nunen S, Loblay R, Clarke L, Swain A (1984). "Adverse reactions to foods". Med J Aust. 141 (5 Suppl): S37–42. doi:10.5694/j.1326-5377.1984.tb133035.x. PMID   6482784. S2CID   222050621.
  8. ↑ Rowe, A. Elimination Diets and the Patient's Allergies. 2nd Edition. Lea & Febiger, Philadelphia, PA: 1944
  9. ↑ Gibson AR, Clancy RL (March 1978). "An Australian exclusion diet". Med. J. Aust. 1 (5): 290–2. doi:10.5694/j.1326-5377.1978.tb112553.x. PMID   661687. S2CID   8897411.
  10. ↑ Gibson A, Clancy R (November 1980). "Management of chronic idiopathic urticaria by the identification and exclusion of dietary factors". Clinical & Experimental Allergy. 10 (6): 699–704. doi:10.1111/j.1365-2222.1980.tb02154.x. PMID   7460264. S2CID   12346266.
  11. ↑ Gerth van Wijk R, van Cauwenberge PB, Johansson SG (August 2003). "[Revised terminology for allergies and related conditions]". Ned Tijdschr Tandheelkd (in Dutch). 110 (8): 328–31. PMID   12953386.
  12. ↑ Johansson SG, Bieber T, Dahl R, et al. (May 2004). "Revised nomenclature for allergy for global use: Report of the Nomenclature Review Committee of the World Allergy Organization, October 2003". J. Allergy Clin. Immunol. 113 (5): 832–6. doi: 10.1016/j.jaci.2003.12.591 . PMID   15131563.
  13. ↑ Johansson SG, Hourihane JO, Bousquet J, et al. (September 2001). "A revised nomenclature for allergy. An EAACI position statement from the EAACI nomenclature task force". Allergy. 56 (9): 813–24. doi:10.1034/j.1398-9995.2001.t01-1-00001.x. PMID   11551246. Archived from the original on 2013-01-05.
  14. 1 2 "Food Allergies and Intolerances". Health Canada. 2004-07-26. Retrieved 2010-12-01.
  15. ↑ "UNL Food: Food Allergies: General information on food allergies and sensitivities". University of Nebraska-Lincoln. Retrieved 2010-12-01.
  16. ↑ Asero R, Bottazzi G (2007). "Chronic rhinitis with nasal polyposis associated with sodium glutamate intolerance". Int. Arch. Allergy Immunol. 144 (2): 159–61. doi:10.1159/000103229. PMID   17536215. S2CID   40295214.
  17. ↑ "Marine Toxins". Centers for Disease Control and Prevention. Archived from the original on 2011-01-09. Retrieved 2010-12-01.
  18. ↑ "Protecting Against Foodborne Illnesses". NSF: The Public Health and Safety Company. Retrieved 2010-12-01.
  19. ↑ "Food allergy or food intolerance". University of Maryland: Medical Center. Archived from the original on 2010-08-08. Retrieved 2010-12-01.
  20. 1 2 3 Ortolani C, Pastorello EA (2006). "Food allergies and food intolerances". Best Practice & Research. Clinical Gastroenterology. 20 (3): 467–83. doi:10.1016/j.bpg.2005.11.010. PMID   16782524.
  21. 1 2 3 Pastar Z, Lipozencić J (2006). "Adverse reactions to food and clinical expressions of food allergy". Skinmed. 5 (3): 119–25, quiz 126–7. doi:10.1111/j.1540-9740.2006.04913.x. PMID   16687980.
  22. 1 2 Schnyder B, Pichler WJ (1999). "[Food intolerance and food allergy]". Schweizerische Medizinische Wochenschrift (in German). 129 (24): 928–33. PMID   10413828.
  23. 1 2 Kitts D, Yuan Y, Joneja J, et al. (1997). "Adverse reactions to food constituents: allergy, intolerance, and autoimmunity". Can. J. Physiol. Pharmacol. 75 (4): 241–54. doi:10.1139/cjpp-75-4-241. PMID   9196849.
  24. ↑ "Vegatest – High Tech Pseudoscience". Neurologica. 2010-08-03. Retrieved 2010-12-01.
  25. ↑ Sullivan PB (1999). "Food allergy and food intolerance in childhood". Indian Journal of Pediatrics. 66 (1 Suppl): S37–45. PMID   11132467.
  26. ↑ Vanderhoof JA (1998). "Food hypersensitivity in children". Current Opinion in Clinical Nutrition and Metabolic Care. 1 (5): 419–22. doi:10.1097/00075197-199809000-00009. PMID   10565387.
  27. ↑ Liu Z, Li N, Neu J (2005). "Tight junctions, leaky intestines, and pediatric diseases". Acta Paediatr. 94 (4): 386–93. doi:10.1111/j.1651-2227.2005.tb01904.x. PMID   16092447. S2CID   45849118.
  28. ↑ MacDermott RP (2007). "Treatment of irritable bowel syndrome in outpatients with inflammatory bowel disease using a food and beverage intolerance, food and beverage avoidance diet". Inflamm Bowel Dis. 13 (1): 91–6. doi:10.1002/ibd.20048. PMID   17206644. S2CID   24307163.
  29. ↑ Carroccio A, Di Prima L, Iacono G, et al. (2006). "Multiple food hypersensitivity as a cause of refractory chronic constipation in adults". Scand J Gastroenterol. 41 (4): 498–504. doi:10.1080/00365520500367400. hdl: 10447/10104 . PMID   16635922. S2CID   24551094.
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