# Differences between Food allergies, hypersensitivities and intolerances



## bonniei (Jan 25, 2001)

Food Allergies, Hypersensitivities and IntolerancesThey are adverse food reaction and indicate any untoward reaction following food ingestion and may be toxic or non-toxic. Reactions may be immunological (*food allergy/hypersensitivity*) or non-immunological (*food intolerance*).An antigen is a foreign substance that can stimulate an immune response when introduced into the body.A true food *allergy* is when IgE antibodies are released in reaction to an antigen. The onset of the reaction is immediate, often within minutes of eating the food causing the allergy, causing symptoms of abdominal pain, vomiting, and diarrhea often associated with extra- gastrointestinal problems such as urticaria, wheeze, or even anaphylaxis. IgE antibodies are believed to trigger allergic reactions when they crosslink on the surface of gastrointestinal mast cells, stimulating the release and production of chemical mediators such as histamine, proteoglycans, and leukotrienes. These potent reactors instigate a barrage of effects on surrounding intestinal tissue and, by inducing intestinal permeability, may also allow passage of food antigens into the bloodstream. When this happens, other organs in the body then become targets for the allergic reaction; further involvement with other cell types in the body may result in the creation of a chronic, perpetual immune response. Testing for Allergies: These IgE-mediated allergies are supposed to correlate well with skin prick tests and Radioallergosorbent test( RAST). 90% of true food allergies in adults are caused by nuts, fish, or shellfish and to a lesser extent cow's milkNon-IgEï¿½mediated food allergies are thought to result from excessive cytokine production by antigen presenting cells or T lymphocytes, which are activated by particular antigens, and these particular reactions tend to be subacute or chronic. Delayed reactions or * hypersensitivities *are primarily mediated by IgG antibodies and it may take hours or even days for the reaction to occur These hypersensitivities also induce increased gut permeability and allow larger food particles to enter the bloodstreanm as in allergies. IgG can induce basophil degranulation, triggering the release of histamine and other potent chemical mediators upon exposure to specific antigensï¿½a common mechanism of allergic reactions.Testing for hypersensitivities: LEAP*Intolerances* on the other hand are non-immunological and involve high levels of active constituents like coffee, or enzyme deficiencies as in lactose intolerance or the absence of the GLUT_5 transporter as in fructose intolerance. Rarely are people with IBS sucrose (table sugar) intolerant. Sorbitol intolerance or malabsorption may be present."Fernandez-Banares et al. [30] gave IBS patients and healthy volunteers lactose, sorbitol, fructose,or sucrose challenges. Malabsorption of at least one sugar was common in IBS patients and volunteers and was identified in 90% of the subjects overall". The offending sugar reaches the colon undigested or/and unabsorbed and the bacteria feed off of it and create gas mainly. With a higher dose diarrhea is likely."Nevertheless, median symptom scores were significantly higher in the IBS group after administration of lactose and sorbitol-fructose than with sucrose. There were no differences in the healthy control group, suggesting that although the prevalence of malabsorption is high in both groups, patients with IBS tend to develop symptoms after ingestion of the malabsorbed sugars. The reasons for this are unclear, but may relate to differences in colonic flora, which cause more gas release in the IBS patients[]. Alternatively, the gut of an IBS patient may react differently to any specific gas load []. Consequently, elimination of these disaccharides may be expected toimprove symptoms in IBS patients regardless of the equally high prevalence of malabsorption in healthy volunteers. Forty percent of patients in this study responded to an elimination diet removing the offending sugar, with other studies reporting similar results."


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## fleure (Dec 26, 2003)

My experience of IBS corresponds closely to Fernandez-Benares' theory. I always get right side spasms in the area of cecum and appendix. I recently read that undigested/maldigested carbohydrate fermentation takes place in that area, so perhaps I'm giving my bacteria a feast and they are repaying me by multiplying and producing lots of hydrogen gas. My colon's solution is to go into spasms. Levsin relieves the spasms but not the gas, which remains trapped. Thanks for the info Bonniei, I will go to the library and read the whole article. fleure


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