What is Food Chemical Intolerance?
Food chemical intolerance is intolerance to salicylates, amines, glutamates or certain food additives that are known to cause issues in sensitive babies (including breast-fed babies), children and adults.
The Royal Prince Alfred Hospital (RPAH) designed the low chemical elimination diet as a way of diagnosing and managing food chemical intolerance. This diet is often referred as the RPAH elimination diet. The Failsafe diet (FED UP Intolerance Network) is based on the RPAH diet but based on the strictest level of elimination with some modifications based on experience of diet responders. All these names are used to describe a diet that limits salicylates, amines , glutamates and food additives such as MSG and preservatives.
While the diet has been shown to be useful for people with food chemical sensitivity, robust scientific evidence such as randomised controlled trials (RCTs) are lacking. There has been some data (not RCTs), suggesting that food chemical restriction may be effective in chronic idiopathic urticaria, eczema, rhinitis, attention deficit hyperactivity disorder and asthma (3-7).
Food is made from a countless number of chemicals. Only a very small number of these are thought to cause food symptoms.
Food chemicals occur naturally in a range of foods and fall into two main groups: naturally occurring food chemicals and food additives.
Naturally occurring food chemicals in food: salicylates, amines (also known as biogenic/vasoactive amines or histamine) and glutamates
Food additives such as preservatives, colours and MSG. Although glutamates can probably fit in this category as MSG (monosodium glutamate) and other flavour enhancers are forms of or closely associated with glutamate.
These food chemicals are thought to produce reactions via
Stimulating nerve endings eg in the gut for people with Irritable bowel (IBS)(8)
Mast cell activation which may for people with IBS increase intestinal permeability and pain perception. This proposal is based on evidence identifying increased intestinal permeability in people with IBS compared with controls (4), a higher density of mast cells in the intestinal mucosa of people with IBS and their co-location with nerve endings, and a role of mast cells in modulating intestinal permeability in IBS (9,11). It is thought that salicylates may activate mast cells by means independent of IgE (12).
While IBS is discussed as an example, food chemicals are thought to affect different parts of the body depending on the susceptibility of the different body systems. That may explain why food chemical symptoms can be so varied.
Intolerance to food chemicals can occur at any age. The prevalence of chemical intolerance is not known- it is thought that 10% of the population may have food chemical intolerance. A recent Japanese study indicated a prevalence of 7.5% in adults.
No two peoples' sensitivities are the same. You may react only to salicylates and some food additives and not amines or glutamates, while the next person may only react to amines. So what you may be reacting to cannot be easily predicted. Even people in the same family can have different symptoms to the same food chemical!
In addition it is common for food sensitive people to react adversely to various medications and/or drugs as well. An overall sensitive constitution is often evident.
Only a carefully constructed Diagnostic Elimination Diet complete with food chemical challenges can help pin point your particular sensitivities. Find out more about the Diagnostic Elimination Diet for Food Chemicals.
There is no one size fits all- only one personal approach for each sensitive individual. Another reason why there is no simple test for Food Intolerances.
1. Skypala IJ, Williams M, Reeves L, Meyer R, Venter C. Sensitivity to food additives, vaso-active amines and salicylates: a review of the evidence. Clinical and Translational Allergy. 2015;5:34. doi:10.1186/s13601-015-0078-3.
2. Swain, A., Soutter, V, & Loblay, R. (2011). RPAH Elimination Diet Handbook with food and shopping guide. Australia: Allergy Unit, Royal Prince Alfred Hospital.
3.Gibson, A. and R. Clancy, Management of chronic idiopathic urticaria by the identification and exclusion of dietary factors. Clin Allergy, 1980. 10(6): p. 699-704.
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8. Raithel, M., et al., Significance of salicylate intolerance in diseases of the lower gastrointestinal tract. J Physiol Pharmacol, 2005. 56 Suppl 5: p. 89-102.
9. Dunlop, S.P., et al., Abnormal intestinal permeability in subgroups of diarrhea-predominant irritable bowel syndromes. Am J Gastroenterol, 2006. 101(6): p. 1288-94.
10. Park, J.H., et al., Mucosal mast cell counts correlate with visceral hypersensitivity in patients with diarrhea predominant irritable bowel syndrome. J Gastroenterol Hepatol, 2006. 21(1 Pt 1): p. 71-8.
11. Lee, H., et al., Mucosal mast cell count is associated with intestinal permeability in patients with diarrhea predominant irritable bowel syndrome. J Neurogastroenterol Motil, 2013. 19(2): p. 244-50.
12. Suzuki, Y. and C. Ra, Analysis of the mechanism for the development of allergic skin inflammation and the application for its treatment: aspirin modulation of IgE-dependent mast cell activation: role of aspirin-induced exacerbation of immediate allergy. J Pharmacol Sci, 2009. 110(3): p. 237-44.