Food allergies are not a phenomenon of our time. The public and published opinion characterize food allergies as an accompanying symptom of our modern industrial society. However, many years before our time, Hippocrates (400 B.C.) and Lucrezius (1. Century A.D.) had described symptoms of illness which seemed to be due to food-allergies and intolerances. Today, allergies (especially food allergies) are often depicted as having increased excessively and that this increase seems to result from harmful substances in the environment, residues, food additives or may even be due to food manufacturing processes. It is estimated that the frequency of all types of allergic illnesses at this time in West-Germany is between 10-20 percent. Taking into consideration all degrees of difficulty, the number of people with food allergies lies under 10 percent of the population, although exact numbers in this area are missing. It is undisputed that food allergies are induced as a result of some of the foreign substances mentioned. However, the predominant share of food allergies occur as a result of natural food substances. The trend towards less processed foods has especially increased the risk of food allergies, since for example unmodified protein may contain more possible allergens than the corresponding protein which has been denatured by heating. The wide distribution of "new" foods from exotic countries and the enormous expansion in the variety of seasonings is also thought of as a cause for many allergies. One cause for more allergens reaching our abundantly set tables is the increased distribution and range of products resulting from expansion of national and international trade. Allergy, which to some extent is due to a malfunctioning immune system, activates certain defense mechanisms in the body. Food or more precisely its contents, then becomes an alien substance or antigen for the body against which it builds certain antibodies to "stay in a good state of health". These antibodies cause typical allergic reaction such as nausea, vomiting, diarrhea, urticaria and difficulty in breathing, after a certain food has been eaten. We must differentiate between food allergies and incompatibility (food intolerances). The body does not produce antibodies for the latter. Unlike food allergies, intolerances can disappear with time.