Food Additive Reactions are Intolerance to artificial and natural chemicals found in packaged, processed and “take-away” fast foods.

by Dr Adrian Morris

Preservatives (to give food a longer shelf-life)

The Sulphites
These chemicals in the form of gases cause lung irritation and may trigger asthma. They are commonly found in liquid form in processed cold drinks and fruit juice concentrates to extend their shelf-life. Also in most wines and sprayed onto cut foods to keep them fresh and prevent discoloration or browning. They are used to preserve smoked and processed meats, dried fruit (apricots) and salads. In the solid form, sulphites can cause urticaria when ingested. ( E220 – E227)

Sulphur dioxide, Sodium sulphite, Sodium bisulphite, Potassium bisulphite and Potassium metabisulphite.

Benzoic acid and Parabens
Benzoates and Parabens have antibacterial and anti fungal properties for prevention of food spoilage. These agents are added to pharmaceutical and food products such as drinks (sugar free Coke) and occur naturally in prunes, cinnamon, tea and berries. They may cause urticaria, asthma and angioedema. (E 210 – E 219 )

Sodium benzoate, Methylparaben, Propylparaben and Heptylparaben.

Fat and oils in food turn rancid when exposed to air. Synthetic phenolic antioxidants (BHA and BHT) prevent this spoilage happening but can trigger asthma, rhinitis and urticaria. (E320 – 321 )

Butylated hydroxyanisole (BHA) and Butylated hydroxytoluene (BHT)).

Flavour enhancers (to enhance food palatability)

Aspartame a low calorie sweetener can occasionally trigger urticaria (nettle rash), itchy hives and swelling of the body.

Monosodium Glutamate (MSG) which can trigger the “Chinese Restaurant Syndrome” of headache and burning plus tightness in the chest, neck and face.  Found in packet soups, pot noodles and instant drinks. (E 620 – E 635)

Colourings (make food visually more attractive)

All colourings must now be labeled. They can trigger hives, urticaria, asthma and generalized allergic reactions.  ( E 100 – E 180 )

Azo dyes (Tartrazine) and Non-azo dyes (erythrocine)

Nitrates and Nitrites give meat a pink colour to look more attractive and found in bacon, salami and frankfurters. ( E 249 – E 252 )

Emulsifiers and stabilisers

Stop oil and water components separating, as in ketchup and mayonnaise, but do not cause adverse reactions.

Naturally occurring substances in food causing adverse reactions

Vaso-active amines
Natural Histamine, Serotonin and Tyramine occur in some ripe cheeses, fish, cured sausage, red wine, chocolate and pickled vegetables and can induce cramping, flushing, headache and palpitations in a dose related manner.

Caffeine found in foods, medication, tea, coffee and Coca-Cola induces dose dependent agitation, palpitations, nausea and tremors.

Salicylates (aspirin-like naturally occurring chemicals)
Salicylates induce urticaria, asthma and nasal polyps to develop. They are found in Curry powder, paprika, dried thyme,  oranges, apricots, ginger, honey, berries and fruit skins, tea and almonds.  Salicylate sensitive individuals also tend to have adverse reactions to benzoates and tartrazine.

Always read all packaged food labels, legislation now ensures that additives must be clearly labelled. E Numbers – all additives used within the European Community must be allocated an E number.

Colourings: (E100-180)
Tartrazine E102, Sunset Yellow E110

Flavourings: (E620-635)
Monosodium Glutamate E620

Preservatives: (E200-297)
Benzoates (E210-219), Sulphites (E220-227), Nitrates (E249-252)

Antioxidants: (E320-321)
BHA (E320) & BHT (E321)

General rules for preservatives and additives:

Many E number additives are completely harmless.  Safe E numbers include: E101 Riboflavin (Vitamin B2), E200-203 Sorbate derivatives, E260 Acetic acid, E280 Propionic acid, E300-304 Ascorbic acid derivatives (Vitamin C), E330-333 Citric acids, E412 Guar gum and E578 Calcium gluconate are just a few examples,

Unfortunately the mechanism of food additive reactions is not well understood. The reactions are not IgE mediated and can be immediate or delayed for a few hours. No accurate diagnostic tests are yet available and even CAST testing (Cellular Allergen Stimulation Testing) produces variable results with false negative results. Allergen Patch testing can be undertaken with extracts of preservatives such as sulphites or benzoate allergens.   These can be applied to the skin for 48 hours in Finn chambers similar to contact allergen testing. Patch testing can also be used for testing Benzalkonium Chloride sensitivity (a preservative in eye preparation).

Relatively few adverse reactions are actually reported when compared to nuts, eggs and other foodstuffs.

However, adverse hyperactive behavioural changes in children have been documented with excess amounts of artificial food colourings and sodium benzoate preservatives in the diet.  This was shown in the Isle of Wight study of pre-school children by Warner et al (Arch Dis Child 2004;89:506-511)

Read food labels carefully, keep a food diary to identify offending additives and preservatives.

Melkersson-Rosenthal Syndrome is a rare disorder possibly triggered by sodium benzoate and characterised by lip granulomas, facial paralysis and a fissured tongue (Oropharyngeal Granulomatosis)  It may occur in atopic individuals.


Ortolani C, Bruinjzeel Koomen C, Bengtsonn U, Wuthrich B et al.  Controversial aspects of adverse reactions to food. Allergy 1999 54 27-45

Written by Dr Adrian Morris
First published July 2012 and last reviewed 2nd January 2019.