Food allergy

Food allergies' following food incompatibilities, which are not caused immunologically. Mostly allergic symptoms are caused by cow's milk or chicken eggs. Allergic reactions are preceded by sensitizing events; certain characteristics of foodstuffs and conditions in the human body facilitate their development. Gastrointestinal symptoms very often are just accompanying signs. In differential diagnosis the so-called "pseudo-allergies' following food ingestion have to be separated. Most important diagnostic measures are clinical history, prick-/scratch test, RAST, gastrointestinal provocation and abstinence test. The therapeutic program consists of allergen abstinence, avoiding all allergy-arousing factors, oral desensitizing and pharmaceutical treatment.     

Food allergy: an overview

Food allergy affects between 5% and 7.5% of children and between 1% and 2% of adults. The greater prevalence of food allergy in children reflects both the increased predisposition of children to develop food allergies and the development of immunologic tolerance to certain foods over time. Immunoglobulin (Ig) E-mediated food allergies can be classified as those that persist indefinitely and those that are predominantly transient. Although there is overlap between the two groups, certain foods are more likely than others to be tolerated in late childhood and adulthood. The diagnosis of food allergy rests with the detection of food-specific IgE in the context of a convincing history of type I hypersensitivity-mediated symptoms after ingestion of the suspected food or by eliciting IgE-mediated symptoms after controlled administration of the suspected food. Presently, the only available treatment of food allergies is dietary vigilance and administration of self-injectable epinephrine.     

Food allergy challenges: guidelines and implications

Double-blind placebo-controlled food challenges were used to determine the presence or absence of food hypersensitivity in 120 children with atopic dermatitis. Foods to be challenged were selected on the basis of history, allergy skin tests, nutritional significance, and patient desires. Dehydrated foods were hidden in capsules or juice and administered twice a day. Antigens were obtained commercially or prepared through a process of freeze-drying and subsequent pulverization. Cutaneous, gastrointestinal, nasal, and/or respiratory symptoms occurred following 133 challenges. Although patients exhibited multiple positive skin tests to foods, 86% experienced a positive response on blinded challenge to only one or two foods. Double-blind placebo-controlled food challenges accurately diagnose food hypersensitivity and minimize the number of foods eliminated from allergy avoidance diets. A new method of elimination diet management and education is based on the identification of "key words" on food labels. Instructional diet sheets were developed to teach this concept, which was found to promote greater confidence, compliance, and creativity in diet planning.     

Food allergy in the XXI century

Food allergy is a clinical state of high frequency and possible risk to life. This article reviews the foodstuffs most often responsible for serious reactions, including data from the Autonomous Community of Navarre. Given that dietetic elimination is the primordial long term treatment for food allergy, its difficulties, limitations and risks are analyzed. Finally, we set out the new perspectives offered by technology in the field of food allergy, both in the production of hypoallergens and in the development of new forms of immunotherapy.     

Food intolerance and allergy in gastrointestinal disorders.

Approximately 60 tonnes of food passes through the gastrointestinal tract in an average lifetime. With a surface area second only to the respiratory tract, it is surprising that adverse reactions to food do not occur more frequently.     

Food allergy: gambling your life on a take-away meal

This study investigates whether or not it is possible to buy meals suitable for peanut allergy sufferers and assesses the training and guidance needs of catering staff and Environmental Health Officers (EHOs) in Northern Ireland with respect to serious food allergies. Meal samples purchased in food premises in the local authority regions of Northern Ireland (NI) were subjected to chemical analysis to check the assertions of the premises staff that they were suitable for peanut allergy sufferers. Officers also assessed if the customer was provided with any information on the allergenic status of foods produced by the establishment; if the EHOs taking the samples had received any training or guidance in allergy-related issues and to gauge the need for such training and guidance. Approximately one in five (13/62) of the premises provided meals which could possibly have triggered a fatal reaction in the purchaser. Most front of house staff did not check the allergen status of the meal with those doing the cooking and most EHOs felt that they needed more training in the subject of food allergen control in commercial food premises. It is important for food allergy sufferers and their medical advisers to be made aware of the limitations of avoidance advice and that false assurances persist of the absence of peanut protein in takeaway foods.     

Impact of peanuts and tree nuts on body weight and healthy weight loss in adults

Nuts (ground and tree) are rich sources of multiple nutrients and their consumption is associated with health benefits, including reduced cardiovascular disease risk. This has prompted recommendations to increase their consumption. However, they are also high in fat (albeit largely unsaturated) and are energy dense. The associations between these properties, positive energy balance, and body weight raise questions about such recommendations. This issue is addressed through a review of the literature pertaining to the association between nut consumption and energy balance. Epidemiological studies document an inverse association between the frequency of nut consumption and BMI. Clinical trials reveal little or no weight change with inclusion of various types of nuts in the diet over 1-6 mo. Mechanistic studies indicate this is largely attributable to the high satiety property of nuts, leading to compensatory responses that account for 65-75% of the energy they provide. Limited data suggest chronic consumption is associated with elevated resting energy expenditure resulting in dissipation of another portion of the energy they provide. Additionally, due to poor bioaccessibility, there is limited efficiency of energy absorption from nuts. Collectively, these mechanisms offset much of the energy provided by nuts. The few trials contrasting weight loss through regimens that include or exclude nuts indicate improved compliance and greater weight loss when nuts are permitted. This consistent literature suggests nuts may be included in the diet, in moderation, to enhance palatability and nutrient quality without posing a threat for weight gain.     

Food allergy and nutrition in early life: implications for later health

Allergic diseases are a common cause of illness in most industrialized countries. Diet during early childhood is an important determinant of the development of allergy, particularly in high-risk infants who have a parental history of atopy. Maternal avoidance of highly-allergenic foods during pregnancy and lactation, prolonged exclusive breast-feeding, the use of a hydrolysed milk formula, and delayed introduction of dairy products, eggs, fish, nuts and soybean are associated with a lower incidence of allergic symptoms and signs. These beneficial effects are observed for as long as 18 years of age. Similarly, nutrition and physical growth are important factors that influence immunocompetence and morbidity due to infections. Small-for-gestational age low-birth-weight infants show prolonged impairment of cell-mediated immunity, antibody responses and phagocyte function. Recent studies indicate the beneficial effect of moderate amounts of Zn given in the first 6 months of life. Thus, diet and nutrition in early life are crucial for the development of allergic and infectious disease throughout childhood and into adulthood.