There are many medical conditions that can mimic the symptoms of food allergies, and cause people to cut out food groups unnecessary. In her previous topic Conditions that mimic food allergies DietDoc outlined conditions such as psychological food aversions, anatomical and digestive problems, and enzyme deficiencies.
This week, DietDoc highlights alcohol intolerance and pharmacological reactions, as discussed by leading SA allergologists Drs Michael Levin and Harris Steinman in an article of the Current Allergy & Clinical Immunology Journal.
The authors Drs Michael Levin and Harris Steinman (2009) point out in their article that alcoholic beverages can cause a whole range of reactions that may lead users to believe that they suffer from a food allergy. Because most alcoholic drinks are a mixture of many different compounds, it is often difficult to pinpoints which ingredient is causing the negative reaction. For example, patients who are truly allergic to wheat may react to beer that contains traces of wheat from the brewing process (Levin & Steinman, 2009).
In very rare cases, patients develop a so-called anaphylactic reaction to components such as acetic acid and acetaldehyde which occur in alcoholic beverages. Alcohol may trigger asthma in some patients or cause the release of histamine which can result in hypersensitivity.
Actual alcohol intolerance is more common that generally believed and certain population groups tend to be more intolerant than others. Drs Levin and Steinman (2009) state that about 45% of the Japanese population suffer from a deficiency of the enzyme acetaldehyde dehydrogenase 2, which can result in alcohol-induced asthma. Using antibiotics like antifungals, sulphonamides or cephalosporins together with alcohol can block this enzyme and cause negative reactions. This is one of the reasons why patients taking antibiotics or antifungals are advised not to drink alcohol during treatment.
Patients who do have a true food allergy, may also find that drinking alcohol can aggravate their allergic symptoms (e.g. flushing syndrome, urticaria, angio-oedema, or shock).
It should also be kept in mind that many alcoholic beverages contain some form of sulphur (e.g. sulphur dioxide, sulphite preservatives), which can cause asthma or other symptoms. Beer and wine are generally preserved with some form of sulphur compound and can trigger reactions in sensitive individuals.
I suspect that many members of the public who are quick to remove innocent foods from their diets due to suspected (but unconfirmed) allergy or sensitivity, won’t easily identify alcohol as the culprit and stop drinking, unless a doctor diagnoses that it is the alcohol and not a food or foods, that is causing their problems.
Drs Levin and Steinman (2009) also mention pharmacological reactions to compounds such as histamine, caffeine, tyramine, theobromine and serotonin. These compounds occur naturally in foods and can trigger severe reactions when a patient eats a normal portion of such a food. These compounds are found in the following foods:
- Histamine - wine, certain cheeses (usually cheeses with a strong flavour), spinach, strawberries, tomatoes, sauerkraut and fermented foods, spoilt fish (so-called scombroid poisoning)
- Caffeine - coffee, tea, cola beverages, cacao, chocolate
- Tyramine - cheeses, beer, chocolate, cured meat like biltong, pickled herrings, and Marmite
- Theobromine - tea, chocolate
- Serotonin - tomatoes, bananas, pineapple and walnuts
(Levin & Steinman, 2009)
In addition to these compounds, many pharmaceuticals and chemicals can trigger adverse reactions.
Aspirin which is probably one of the most commonly used analgesics and blood thinners in the modern world, can cause hypersensitivity reactions including asthma and urticaria.
Eating monosodium glutamate (MSG) can result in headache and flushing in sensitive individuals (so-called “Chinese Restaurant Syndrome”), although the incidence of this sensitivity is relatively low and most people can dine on foods containing MSG without developing reactions.
Unabsorbable wax esters in certain types of fatty fish like butterfish can cause diarrhoea.
Most food additives including colourants like carmine, tartrazine, red FD&C No.2 and brilliant blue, and preservatives such as sodium benzoate are implicated in pharmacological reactions, which may mimic true food allergy (Levin & Steinman, 2009).
If you develop reactions such as asthma, urticaria and other skin conditions, diarrhoea, headaches, flushing or nausea after eating certain foods or drinking beverages like alcohol or cola drinks, it may be advisable to have yourself tested for alcohol and/or pharmacological sensitivity. If you are sensitive to a compound like acetaldehyde found in most alcoholic drinks or tyramine in biltong, then it is important that you are aware of which foods and drinks you need to avoid, because some of these reactions can be severe and even life-threatening.
Also keep in mind that many other products like pharmaceuticals and over-the-counter medications can contain the offending compounds. It is no use cutting out all the foods or drinks that contain a specific compound and then taking an over-the-counter medication which contains a high dose of the compound you need to avoid!
It is, therefore, important to be aware of where such compounds are used and to read all labels and package inserts. For example, you need to mention to your pharmacist that you have an aspirin sensitivity when you purchase any prescribed medicine. If you buy an over-the-counter medication and can’t figure out if it contains a compound you will react to, take it to the pharmacist and ask him or her to check if the product is free of the trigger chemical. Rather safe, than sorry.
The article by Drs Levin and Steinman (2009) on Mimics of Food Allergy, underlines the importance of finding out exactly what is causing your negative reactions instead of randomly removing innocent foods from your diet, and also emphasises that there are many other compounds, chemicals and ingredients, besides foods, that could be responsible for your reactions. In the case of adverse reactions, accurate knowledge is vital and can even save your life in extreme circumstances.
- (Dr IV van Heerden, DietDoc, July 2011)
(Levin ME, Steinman H (2009). Mimics of food allergy. Current Allergy & Clinical Immunology, Vol 22(3):110-116)
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