Dietary Intolerance Reactions: Food Allergies and Intolerances

Dietary intolerances (intolerance reactions) are divided into toxic and nontoxic reactions. Food intolerance (synonym: food intolerance, NMU) is referred to as a “nontoxic reaction” or “hypersensitivity.” This is the generic term for food allergies (food allergies), enzymatic intolerances and pseudoallergies (“pharmacological intolerances and intolerances to food additives” ). All three intolerance reactions lead to different clinical pictures or symptom combinations in ill persons, which occur through exposure to a defined stimulus, which is tolerated by healthy persons without problems [1.2., 2, 5]. The prerequisite for a reaction is an individual disposition, i.e. the diseased person has a congenital or acquired malfunction of the defense mechanisms or the target cells or target organs. Food intolerances may also be the cause of toxic reactions, for example, due to food poisoning – consumption of spoiled food, mushrooms, etc. Symptoms may be triggered by a variety of foods through different pathomechanisms and by different routes (per ingestionem, per inhalationem, permucous, percutaneous and hematogenous). Accordingly, food allergies, food intolerances (enzymatic intolerances), and pseudoallergies differ in their respective pathogenic mechanisms. Typical clinical symptoms of an intolerance reaction include, for example, arthritis, asthma, abdominal pain, flatulence, diarrhea, fatigue, swelling, or headache. In all three cases, the therapy is the same – contact with the allergens or triggers in the corresponding foods must be avoided to prevent the body from reacting again. If the number of foods to be avoided as well as food groups is large, the coverage of the nutrient and vital substance requirements (macro- and micronutrients) can be endangered. Affected persons should thus pay attention to an increased intake of the corresponding vital substances (micronutrients) via alternative foods. The most common triggers for hypersensitivity reactions are found in:

Wheat, oats, corn
Eggs
Dairy products, cow’s milk
Fish, crustaceans, shellfish
Nuts – especially peanuts and hazelnuts
Soybeans and -beans
Yeast
Citrus fruits
Various vegetables and fruits, such as tomatoes, celery, carrots and apples.
Chocolate, tea, coffee
Alcohol
Food coloring, additives and preservatives – sodium glutamate,yellow azo dye tartrazine (E 102) or yellow orange S (E 110)/frequently used as a dye in medicines* , salts of benzoic acid, vanillin, sulfite-based preservatives in fresh products, salads, potatoes, wine * Other dyes in medicines with allergy risk are: Quinoline Yellow (E 104), True Yellow (E 105) and Ponceau 4R (E 124)!

Forms of food intolerances

Allergy	Pseudoallergy	Intolerance
Immune response	Non-immunological reaction	Congenital or acquired enzyme defects (on fructose, lactose).
Allergens – IgE, IgG/M, IgA, cellular.
Allergic reaction	Pseudo-allergic reaction (pharmacological intolerance or intolerance to food additives).	Disorder in the gastrointestinal tract, metabolic disorder. Disorder of absorption (absorption) of the sugar alcohol sorbitol (sorbitol) in the small intestine.
Hypersensitivity (atopy) “True” food allergy, for example, to. Chicken protein, cow’s milk, wheat, fish, crustaceans and mollusks, soy, nuts, seeds, celery, pollen-associated fruits and vegetables, such as stone and pome fruits or carrots, spices, herbs, and other foods.	Pharmacological intolerance due to Degradation products of food proteins – biogenic amines (especially histamine and tyramine), with affected individuals lacking the enzymes necessary for amine degradation. Hypersensitivity to food additives Naturally occurring in food salicylates (salicylic acid), benzoates – p-hydroxybenzoic acid – and flavorings. Preservatives: benzoic acid, sorbic acid, PHB esters, propionic acid, nitrite, sulfur dioxide, sulfites. Dyes (azo dyes). Antioxidants Flavorings Flavor enhancers – glutamate/glutamic acid? * Sweeteners – aspartame (asparagylphenyl-alanine methyl ester). Pesticide residues Components of medicines	Inherited (hereditary) intolerance to fructose and lactose. Intolerance to antioxidants, such as sulfur dioxide (E220), due to deficiency of the enzyme sulfite oxidase. Phenylketonuria (PKU) – congenital enzyme defect in which the amino acid phenylalanine can not be broken down.

* In scientific studies, glutamate is repeatedly mentioned as a trigger of pseudoallergic complaints. As complaint picture headache, pressure feeling in the neck etc. are described. The “clinical picture” is called China Restaurant Syndrome. However, double-blind studies have not been able to confirm that glutamate is the cause of the complaints (FAO/WHO expert commission). Food intolerances may also be the cause of toxic reactions or psychosomatic reactions:

Toxic reactions – for example, poisoning by bacterial toxins or biogenic amines in food that is not hygienically safe, accompanied by symptoms such as general discomfort, indigestion, and cardiovascular symptoms. Toxic reactions can occur by ingestion of a sufficiently high dose of the toxic substance in any person susceptible to food intolerance.
Psychosomatic reactions – for example, hyperkinetic syndrome, being a behavioral disorder in children characterized by hyperactivity, inattention, distractibility, impulsivity or aggressiveness and learning disorders. A food allergy is suspected as the trigger of the psychosomatic reaction, since individual foods can lead to corresponding symptoms. In children with hyperkinetic syndrome, the respective foods or ingredients should be avoided for therapy and therapeutic measures for behavior modification.