The fact that there is a link between allergies and food was already highlighted by the existence of the so-called oral allergy syndrome, a disease that occurs in the case of cross allergies, when allergens such as pollens, mites or other apparently very different foods share proteins and trigger the abnormal response of the immune system: a dangerous cross which, according to allergists, is increasingly common, as well as are increasing allergies in general. The reason would also lie in the diet, if it is based on too-fat foods. We talked about it with Professor Giorgio Walter Canonica, head of the Center for Personalized Medicine Asthma and Allergology of the Clinical Institute Humanitas.
Fat-rich diet, possible cause of allergy
Allergies are constantly on the rise. Experts from the American Academy of Allergy, Asthma and Immunology also pointed this out during the last congress in San Francisco, also discussing the interactions between allergy and diet. According to the American researchers, one of the main causes of this process is the diet. A high-fat diet would encourage the increase of substances towards which the individual can develop allergic reactions. It only takes six months a diet in which 40 percent of the calories come from fat to radically modify the intestinal bacterial flora, increasing the species that favor inflammation and “derailment” of the immune system towards allergies.
Food allergies, the most common in the US
“The diet may affect the possibility of developing allergies, especially food allergies: not by chance these are much more frequent in the US, while in Italy they are less common due to the protective effect of the Mediterranean diet – said Prof. Canonica, former president of the Italian Society of Allergology, Asthma and Clinical Immunology (Siaaic) -. The cross reactions are not so frequent or inevitable in allergy sufferers, but it is important to identify them to give advice to the patients who may have discomfort by eating some foods but never have connected the problem to their allergy. To identify cross allergies we need a molecular allergological diagnosis, i.e. tests that sift through panels of dozens and dozens of molecular-allergens identifying those by which the patient reacts and thus identifying all possible cross-reactivity. If, for example, the person is allergic to the tropomyosin of mites, he will also have problems eating crustaceans and snails”.
Climate change is also responsible for allergy
“The cases of cross allergies are growing mainly because all the others are on the rise, due to lifestyles but also to climate change – continued the allergist – the higher the temperatures, the more pollen in the environment increases. Added to this is the pollution, which damages the respiratory mucous membranes making them more permeable to antigens and therefore more exposed to allergic sensitization: particles exhausted from diesel, for example, increase the production of immunoglobulins E, among the main mediators of the allergic response.
In short, there are many factors. But there are some tricks to be put in place. The World Association for Infectious Diseases and Immunological Disorders has published a decalogue to defend itself from pollen. “Those who suffer from allergic rhinitis and or asthma should undergo specific immunotherapy – concluded the professor -: it is effective in controlling symptoms and can be done even just before and during the allergic season, with subcutaneous injections once a month, drops or sublingual tablets, which exist recently for mites and grasses. Specific immunotherapy is very useful, but only 5 percent of those who would be a suitable candidate do so, with regional differences in access.