Allergy to Soy

Food allergy, an allergy to soy products can prove to be very difficult for the sufferer. Soy is a very frequently used ingredient in processed foods making an avoidance strategy very difficult. As with other allergens, reactions can be caused by even very small quantities of soy protein, and anaphylaxis to soybean protein has been reported. Soybean lectin has also been associated with allergic reactions.

Soybeans may be ingested as whole beans, as flour, or as oil. They may also be used in the manufacture of food in a vast variety of ways. Soy has been used as a texturizer, and emulsifier, and a protein filler. Soy may be listed on ingredient panels according to use and may be shown as hydrolyzed protein or lecithin rather than listed as soy.

Items on ingredient labels that would indicate the presence of soy protein include:

  • ¬†Gum arabic
  • Bulking agent
  • Carob
  • Emulsifier
  • Guar gum
  • Hydrolyzed vegetable protein (HVP)
  • Lecithin
  • Miso
  • MSG (Monosodium glutamate)
  • Protein
  • Protein extender
  • Soy flour
  • Soy nuts
  • Soy panthenol
  • Soy protein
  • Soy protein isolate or concentrate
  • Soy sauce
  • Soybean
  • Soybean oil
  • Stabilizer
  • Starch
  • Textured vegetable protein (TVP)
  • Thickener
  • Tofu
  • Vegetable broth
  • Vegetable gum
  • Vegetable starch

Soybean flour is also often added to cereal flour and it is used extensively in the baking industry. Most breads contain at least some soy flour among their ingredients. Also, pastries, cakes, biscuits, and baby foods may also contain soy flour. Soy flour is also used in the manufacture of processed meat products, including sausages and hamburgers. Fermented soy is widely used in the food of the Far East and may be used in the preparation of soy sauce or Worcestershire sauce.

Soy may also find its way into products as a compound ingredient, being an ingredient in one of a food’s ingredients. One example is margarine. Soy may be used in margarine but if a product includes margarine as an ingredient soy itself is unlikely to be listed on the ingredients panel.

Soy protein isolate or concentrate is used to emulsify fat in some food products. Thus, it may used in the manufacture of ice cream, mayonnaise, and other foods that contain liquid fat or oil. The concentrate or isolate has also been known to be used in soymilk and as protein concentrate added to health foods and high-protein biscuits.

Foods that may contain soy protein include:

  • Baby foods
  • Bakery goods
  • Black pudding
  • Bread (esp. high-protein bread)
  • Breakfast cereals (some)
  • Burger patties
  • Butter substitutes
  • Cakes
  • Candy
  • Canned meat or fish in sauces
  • Canned or packaged soups
  • Canned tuna
  • Cheese (artificial) made from soybeans
  • Chinese food
  • Chocolates (cream centers)
  • Cookies
  • Cooking oils
  • Crackers
  • Desserts
  • Gravy (sauce) powders
  • Hamburger patties
  • Hot dogs
  • Hydrolyzed vegetable protein (may be wheat)
  • Ice cream
  • Infant formula (including cow’s milk formula)
  • Liquid meal replacers
  • Margarine
  • Meat products (e.g., sausages, pastes, Vienna sausages [wieners])
  • Muesli
  • Pies (meat or other)
  • Powdered meal replacers
  • Salad dressings
  • Sauces (e.g., Worcestershire, sweet and sour, HP, Teriyaki)
  • Seasoned salt
  • Shortenings
  • Snack bars
  • Soups
  • Soy pasta products
  • Soy sauce
  • Soy sprouts (Chineserestaurants)
  • Soybeans
  • Stews (commercial)
  • Stock cubes (bouillon cubes)
  • Tofu
  • Tofutti
  • TV dinners

Although soybean oil was thought to be safe for those suffering from soybean allergies, evidence shows that the soy protein may still occur in soybean oil. The presence of soy protein in soybean oil is dependent on the purity of the oil, which depends on the extraction process used. Soybean oil is used in salad dressings, margarine, baby foods, industrial components, linoleum, paint, plastics, soap, and glue for plywood.

Other sources that may result in contact with soy protein include:

  • Adhesives
  • Blankets
  • Body lotions and creams
  • Dog food
  • Enamel paints
  • Fabric finishes
  • Fabrics
  • Fertilizers
  • Flooring materials
  • Lubricants
  • Nitroglycerine
  • Paper
  • Printing inks
  • Soaps

Research has suggested that there may be cross-reactions between soy and other members of the legume family. Evidence for broad cross-reactivity has been provided by RAST and skin tests. Still, it is rate to have a symptomatic reactivity to more than one member of the legume family and being hypersensitive to one member of the legume family, such as soybean or peanut, does not require that all legumes be eliminated from on