What is soya?
The soya bean is a pulse. Pulses are sources of protein, starch, oil and fibre, all of which may be ingredients in processed foods.
What is soya allergy?
Soya allergy is a type of food allergy. Allergic reactions to foodstuffs occur where the body reacts to individual proteins in the food. Some individuals suffer severe reactions from only minute quantities of the foodstuff to which they are intolerant. Food allergy is more common in children than in adults. Most adults grow out of the food allergy as small children. Many children, who have food allergy, react to several foodstuffs. Where a food, which is an important source of nutrition, has to be excluded from the diet it is important to find good alternatives to replace the item in order for the diet to remain healthy. Sensitisation with soya is relatively common whilst meaningful allergy to soya is rare.
What foods contain soya protein?
As soya protein has a high nutritional content and many functional properties, it is used as an ingredient in a variety of foodstuffs. Soya protein can for example be found in hamburgers, fishcakes, pizza, bread and other baked goods. Many replacement products for individuals with milk allergy and coeliacs are based on soya. This is because soya protein is a good alternative (due to its nutritional content and technical functions) to milk protein and gluten. By removing the water in the soya beans, products are made which are used as milk and cheese. By use of other processes, soya sauce, miso, tofu and tempe are also made from soya beans.
What reactions occur in soya allergy?
The kinds of reactions occurring in individuals with soya allergy (having eaten soya) vary. Reactions include diarrhoea, stomach pain, worsening of eczema, asthma and allergic shock.
How is soya allergy treated?
The only means of treating soya allergy is to exclude all foodstuffs containing Soya protein from the diet.
What can an individual with soya allergy eat?
Soya protein is not found in pure products derived from milk, egg, meat, fish, shellfish, fruit, nuts, oil or vegetables. As individuals with soya allergy however suffer reactions to other legumes such as peas, beans, lentils and peanuts, and have to avoid these foods. Soya protein is rarely found in confectionery and snacks. Vegetarian food, foreign meals and health-food products more commonly contain soya protein than typical Norwegian foodstuffs.
Many individuals with soya allergy also have other food allergies.
Since soya protein is used in increasingly more foodstuffs, it is important to read the food ingredients carefully.
What about soya oil and vegetable oil?
Soya oil (which is often called vegetable oil in the ingredients list) is considered to be safe for individuals with soya allergy. The manufacturing processes remove the proteins, which are the materials in the oil that cause the allergic reactions. In other countries, analyses have been performed on oils with the conclusion that soya protein is found in some of them. Some of the largest manufacturers in Norway routinely take samples in order to check that there is no residue of soya protein in oil/margarine.
What about soya lecithin?
Soya lecithin may contain traces of soya protein due to contamination during manufacture. Such instances are a matter of very small quantities, and since soya lecithin is used in small quantities in the finished food product, one would not normally advise individuals with soya allergy against eating food products containing soya lecithin.
What about hydrolysed vegetable protein (HVP)?
Hydrolysis means that the proteins are broken down such that they no longer possess the same properties. This can mean that they do not trigger allergic reactions.
Labelling of foodstuffs
Where a foodstuff contains soya, this should appear in the declaration of contents.
Ingredients one should use caution with are soya protein, soya flour, miso, soya beans, tofu, vegetable protein and soya sauce.