Autoimmune Thyroid Disease

An Unfortunate and Lengthy Adventure in Misdiagnosis

Prevalence of chronic food chemical induced asthma

with 8 comments

I like this study abstract so much I’m going to repeat it:

Allergic-like reactions to chemical components of foods and medicines may be common. The prevalence of idiosyncratic reactions to aspirin, salicylate, metabisulfite and tartrazine is not known. We used a tertiary referral clinic population to estimate safe exposure doses for epidemiological studies. A 15% decrease in the amount of air expired in one second was defined a positive response. The median effective molar doses of the agents were remarkably similar: metabisulfite 0.19 mM, 34.4 mg [95% confidence interval (CI) 0.14, 0.27 mM]; tartrazine 0.10 M, 55.0 mg (95% CI 0.05, 0.21 mM); aspirin 0.09 mM, 16.5 mg (95% CI 0.04, 0.19 mM); and salicylate 0.11 mM, 15.3 mg (95% CI 0.05, 0.27 mM). Doses to which the most sensitive (5%) and practically all (95%) susceptible persons might respectively respond are: metabisulfite 4.6 mg, 255.8 mg; tartrazine 3.4 mg, 885.6 mg; aspirin 0.8 mg, 332.3 mg; and salicylate 2.6 mg, 89.9 mg. Doses within these ranges can be used in epidemiological studies. Aspirin, salicylate, sulfite and tartrazine induced bronchoconstriction. Safe doses and case definition in epidemiological studies. Corder EH, Buckley CE 3rd, J Clin Epidemiol 1995 Oct;48(10):1269-75

This is absolutely fantastic because it gives us a good overview of the problem. People have very different levels of enzymes in their bodies.

Food Chemical Most Sensitive (5% of population) Median Sensitivity (50% of population) Least Sensitive (95% of population)
Metabisulphite 4.6 mg 34.4 mg 255.8 mg
Tartrazine 3.4 mg 55.0 mg 885.6 mg
Aspirin (acetylsalicylic acid) 0.8 mg 16.5 mg 332.3 mg
Salicylate 2.6 mg 15.3 mg 89.9 mg

According to a study run by the RPAH:

The role of a commonly ingested food additive, the preservative sodium metabisulfite (MBS), and aspirin (ASA), in chronic asthma has been studied in 29 children. After 1 week on a strict elimination diet, all 29 children were challenged, in a single-blind fashion, in the pulmonary function laboratory on three consecutive days with placebo, MBS (capsule form and solution), and ASA. Children with a positive response to MBS were prescribed a diet that excluded foods containing MBS. Patients with a positive response to ASA were prescribed a diet excluding medications containing aspirin and natural salicylates. After 3 months on these restricted diets, the children were reassessed to determine whether there had been any therapeutic response. There was a 66% (19/29) incidence of positive challenge (greater than 20% decrease in forced expiratory volume in one second) with MBS and a 21% (6/29) incidence of positive challenge with ASA. None of the children reacted to MBS in capsule form (maximum dose = 100 mg), but 19/29 reacted to MBS in solution with 30 mL of 0.5% citric acid. After 3 months on the restricted diet, four of 19 children on the MBS-free diet and one of six on the salicylate-free diet had objective signs of improvement, namely, reduction in asthma medications and/or improvement in lung function. Unfortunately, compliance with the restrictive diet during this 3-month period was poor, particularly with the ASA-sensitive children. Role of acetyl salicylic acid and sodium metabisulfite in chronic childhood asthma. Towns SJ, Mellis CM, Pediatrics 1984 May;73(5):631-7

So, according to this study, 66% of asthmatic children reacted to metabisulfite, and 21% of asthmatic children reacted to acetylsalicylic acid (ASA/aspirin).

Bearing in mind that the population distribution for reactions to acetylsalicylic acid exhibits much broader variance than the distribution for individuals reacting to salicylate (0.8-332.3 mg for ASA, 2.6-89.9 mg for salicylate), the RPAH may have underestimated the number of individuals who respond to salicylate in this challenge, by presuming ASA and salicylate to be equal in effects.

The reason for this variation might be because acetylsalicylic acid is acetylated and salicylate is not, requiring slightly different detoxification pathways. Most chemicals, including aromatic ring structures, are detoxified by multiple pathways in the liver, and by other non-liver methods like sweating too. Intolerance reactions occur when we have exceeded our total, overall capacity to detoxify these chemicals. Acetaldehyde dehydrogenase is one enzyme that varies vastly in capacity across populations, some people have very poor clearance – making them susceptible to “hangover” symptoms after alcohol consumption, whereas others, having better capacity, have never experienced a hangover in their life. A genetic mutation in the acetaldehyde dehydrogenase gene is responsible for the alcohol flush reaction seen in many East Asians. Many rosaceans experience alcohol-related flushing too.

Perhaps one of the most interesting things about the first set of statistics is that the doses at which 50% of the population react to salicylates (15.3 mg) are much lower than both metabisulphite (34.4 mg) and tartrazine (55.0 mg)!

As one aspirin tablet contains 300 mg of acetylsalicylic acid, it’s obvious that the vast majority of the susceptible population – in this case individuals with asthma – are going to experience food intolerance related bronchoconstriction to painkillers. But rarely do sensitive individuals associate wheeziness with the painkillers they took the day before. Occasionally one might be lucky and have instant reactions to medications, like my younger sister, who figured out for herself that ibuprofen tablets (similarly structured to aspirin) induce asthmatic wheezing.

Now, if we suspend disbelief for a moment and pretend that fruit and vegetables only contain salicylate and do not contain acetylsalicylic acid, all that those 5% of the susceptible population have to do in order to react to food chemicals, is to eat one apple, drink one cup of coffee, have some mixed salad for lunch, and some broccoli for dinner. Those are relatively low salicylate choices! Alternatively they might just drink a cup of tea. The result is chronic food-induced asthma that dogs an individual through childhood and is only slowly reduced during the teen and adult years in response to an increased dominance and capacity of the glucuronidation detoxification system over the sulphation system.

It would be nice to see the Gaussian distribution for these sensitivities, because we are not looking at an even, bell curve shape. The article quotes median sensitivity levels for ASA as 16.5 mg and salicylate as 15.3 mg. In terms of food this is one cup of tea, or two 100g servings of olive oil, honey, raspberries, plums, dates, grapes or dried grape derivatives, or mints, or three 100g servings of almost all fruits. Now we are starting to see why salicylate-induced chronic asthma is so common.

I doubt very much that the government was even aware of asthmatic sensitivity to salicylates in its “five a day” fruit and vegetables policy (if it was, the policy is immoral). Additives aside, implementing such a policy on asthmatic children would grossly increase the likelihood of an asthma attack. Most 100g servings of vegetables contain between 0.5-1.0 mg of salicylate. Most 100g servings of fruits contain between 2.0-7.0 mg of salicylate. It is entirely possible to get a dose of between 15-35 mg on such a bulky, plant-based diet, a dosage to which at least half of all asthmatics – somewhere around 5-10% of the general population – would react.

Asthmatics are only one subgroup who have been shown to be food chemical intolerant. Asthma is a result of interactions between genes and the environment. The few genes which have been discovered for asthma are not directly related to food intolerance or liver enzymes, rather to a particular propensity for irritation in the lungs. This implies that asthmatics may not be disproportionately affected by food chemical intolerance, rather they show their vulnerabilities more readily than other groups, who may experience food chemical intolerances in different ways according to their own genetic or congenital susceptibilities – for depression and bipolar disorder, migraines, ADHD, eczema, ear and eye problems, tourettes, digestive ailments, epilepsy, or other conditions. The implications for the population at large are staggering, and it is about time someone took on the task of performing an elimination/challenge diet on members of the general adult population to establish a few statistics.


Written by alienrobotgirl

14 September, 2006 at 9:39 am

Posted in The Science of FCI

8 Responses

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  1. I’m athsmatic, and I’ve awlays though there was ‘more to it’ than just using reliever drugs!Thanks for fighting the good fight!


    15 September, 2006 at 1:13 pm

  2. I’ve been reading your stuff for a while but haven’t posted so far.I’m very impressed by the depth of your research. Fascinating stuff.Have you read any of Art DeVany’s stuff – for example approach is to vary food intake to the extreme to reduce the toxic load that his body is facing. He also avoids dairy grains and legumes of course.


    15 September, 2006 at 9:59 pm

  3. Aww, thanks Chris, what a lovely comment, especially from a complete brain like you! I’ll be sure to keep an eye on Art DeVany.Thanks to Dave too! Dave – I almost qualify as a carnivore these days!

    Alien Robot Girl

    16 September, 2006 at 2:07 pm

  4. Ah yes, this is all about supertasting!

    Alien Robot Girl

    19 September, 2006 at 10:24 am

  5. Interesting piece on broccoli


    19 September, 2006 at 10:19 am

  6. Anonymous

    20 September, 2006 at 8:24 am

  7. I just found your blog though Lowvcrb Dave and I see that I have lots to read and learn befor eme. (I am a supertaster, and Aspirin makes me _really_ sick…with a bunch of food sensitivities and other stuff…)Thnaks for sharing your knowledge, I will check back often.


    23 September, 2006 at 4:01 pm

  8. Hi detox, I’ve had a quick look at your blog, and it does look like you could be helped by this diet! Your experiences must be similar to mine, having come from a low-carb perpective and found that to help. I hope you’ll consider doing failsafe to see if it will help you. Just take a look at the links down the left hand side of my blog, and try the trial elimination diet!

    Alien Robot Girl

    24 September, 2006 at 10:23 am

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