The most common foods associated with allergies are nuts, eggs, milk, corn, groundnut and seafood. Consumption of even the smallest trace of any ingredient will lead to an allergic reaction. People can react to foods in a variety of ways. Those who are lactose intolerant have an enzyme deficiency and cannot break down the lactose in milk and other dairy products. Some cannot eat wheat or any gluten products because of the Celiac disease, an autoimmune disorder. IgE-mediated allergies are particularly serious, with the danger of the life-threatening reaction known as anaphylaxis.
An allergic reaction occurs when the body's immune system perceives a normally harmless substance as a threat. The substance is called an allergen. The immunising cells begin to produce antibodies known as IgE, a class of immunoglobulin. These antibodies attach themselves to skin cells and mucus membranes. When the allergens reach the cells with the IgE antibodies, the cells release histamine and other inflammatory chemical substances. The result of these chemical substances in the surrounding tissue is an allergic reaction. Reactions can vary from less severe swellings or redness to an asthma attack or the fatal anaphylaxis.
The causes of these allergies and what can be done against them are the primary topics of the EU-funded project EuroPrevall. The project is coordinated by Dr Clare Mills from the Institute of Food Research in Norwich, UK.
Researchers from the Vienna General Hospital in Austria are also involved in the EuroPrevall project. Their contribution revolves around the improvement of allergy diagnosis. One current method is the skin prick test, where, as the name suggests, the doctor pricks the skin of the patient and then analyses the reaction to an introduced food substance. However, it can be hard to identify the source of someone's allergy, since some allergens are found in several foods. It is only one protein, rather than the food as a whole, that the patient is allergic to. Researchers at the hospital break down the suspect foods to isolate, extract and purify the proteins. In this form the structure and properties of the protein can be better analysed and more reliable diagnostic methods can be designed. More knowledge about these particular proteins would also enable more effective management of the food allergies.
One of the sixty-three partners of EuroPrevall is VBC Genomics, a biotechnology firm in Vienna. They have developed a new diagnostic tool that allows researchers to test for hundreds of different allergens with the same drop of a patient's blood. The trick behind the device is to have a library of allergens all on the one chip so that they can all be screened for simultaneously. Compared with conventional testing this new system is very cost-effective and reduces the loss of blood from the patient.
EuroPrevall is also seeing that consumer demands are met by the food industry. The public have requested better labels with more detailed information for food products.
The percentage of European adults who suffer from food allergies is 2-4% and 6% for children younger than three years old. EuroPrevall has already shown that the levels of food allergies differ between different regions of Europe. In countries like the Netherlands and Switzerland food allergies are much more common than in Bulgaria or Greece. The EuroPrevall researchers are trying to find out why this is so. An idea of why one person has a particular food allergy and another person doesn't will bring researchers much further in the search for a true cure; so that in the future an allergy can be treated rather than tolerated.