Useful facts on hypersensitivity to additives (tilsetningstoffer i mat)
Additives and hypersensitivity
Useful information concerning additives – NAAF’s fact sheet
What are additives?
“Additives” is a collective term for substances which are added to food in order to increase its shelf-life, as sugar substitutes, to give a specific taste, consistency or colour. Additives are always declared in the product contents. Sometimes they are declared by name and sometimes using a European code (E-number).
Additives are divided into four main groups according to their function, e.g. preservatives, antioxidants, thickeners and colourings. All have specific functions.
Preservatives (E-numbers 200-299) and antioxidants (E 300-399) are added to prolong the shelf-life of a foodstuff by inhibiting growth of bacteria, mould and yeast, and prevent them becoming rancid.
Colourings are added to give food a desired colour (E 100-199).
Thickening agents (E 400-499) are used to give the products the desired consistency.
Sweetening agents are another common form of additive (E-numbers from 950).
What reactions occur in hypersensitivity to additives?
Additives are generally safe for most persons with allergies, as they never contain milk, lactose, gluten, fish, shellfish or nuts. It is not usual to react to additives; however, some substances have been known to cause hypersensitivity reactions in some individuals. The reactions will largely be due to non-allergic hypersensitivity, rather than an allergy, and the amount consumed will be of significance. The most common symptoms from additives are skin reactions, such as flare-up of eczema, reddening of the skin, itching and urticaria.
Which food additives are likely to cause a reaction?
Sulphur dioxide and sulphides (E220-227) are preservatives, which are normally added to dried fruit, sun-dried tomatoes and wine. Up to 5% of asthmatics appear to react to these substances, which is likely due to the release of sulphur dioxide gas when the food reaches the stomach, and this gas irritates the airways.
In some rare cases, colouring agents can bring on an allergic reaction. This applies to both synthetic and natural substances. Examples include the red colouring agent carmine (E120) and the azo dyes E102, E112, E110, E122-124 and E151.
Among preservatives, benzoic acid and related compounds (E210, E211-213, E214-219) are most commonly used. These have been reported to possibly induce skin reactions or intestinal/stomach discomfort. Benzoic acid is also found naturally in berries and fruit, particularly in lingonberries and cranberries.
BHA (E320) and BHT (E320) that can be added as antioxidants in chewing gum, have been reported to cause swelling of the lips and face.
Glutamic acid (E620), a natural amino acid, in large amounts, can cause headaches, sweating and flushing of the skin (Chinese food syndrome).
Sugar alcohols (i.e. sorbitol, mannitol, isomalt) and the thickening agent polydextrose can have a laxative effect in large amounts, as they are not completely absorbed in the gut. This can be compared to the effect of a large amount of high-fibre foods, and is not an allergic reaction per se.
Who develops hypersensitivity to food additives?
Hypersensitivity to food additives occurs more frequently in atopic individuals. The reaction is normally dose-dependent, i.e. it depends on ingesting a certain quantity of the substance.
How are individuals with hypersensitivity to food additives treated?
The treatment is exclusion of foodstuffs with non-tolerated additives from the diet.
Which foodstuffs contain these additives?
Cordial and jam contain preservatives. Sauces, soups and dressings contain both preserving agents and thickeners. Not least, confectionery and soft drinks contain colouring agents, preservatives and artificial sweeteners.
Many of the most common food additives are also found in nature (e.g. benzoic acid in blueberries, lingonberries and cloudberries), and naturally in food, e.g. beta-carotene, beetroot colouring, chlorophyll, beeswax, citric acid and pectin. The majority of additives, however, are artificially manufactured, including those which occur naturally. Requirements are laid down that food additives shall not contain plant residue or chemicals from the production process.
It is not the case that synthetic substances are more “hazardous” than naturally occurring substances.
How are food additives labelled?
All food additives must be labelled, in both pre-packed goods and loose weighed products. Additive substances and other ingredients are labelled in decreasing order by weight. Additionally, additives must be labelled with their class designation, which states the additive’s function in the product, and specific name or E-number.
Food marketed for infants, i.e. children below the age of three years, is designated children’s food. Children’s food may only contain those additives which are necessary for manufacture of the food. Colouring agents, sweeteners, preservatives and antioxidants are not approved for use in these products.
Can food additives contribute to hyperactivity?
Food additives have, on occasion, been blamed for hyperactivity in children. Currently, we do not know enough about the causes of hypersensitivity reactions and hyperactivity and in studies, no clear correlation has been found between the consumption of additives and hyperactivity.
One practical tip if there is a suspicion of hypersensitivity is to exclude such products from the diet for a period, in order to assess whether this leads to fewer symptoms.