Zuidmeer, L., K. Goldhahn, R.J. Rona, D. Gislason, C. Madsen, C. Summers, E. Sodergren, J. Dahlstrom, T. Lindner, S. Sigurdardottir, D. McBride, T. Keil, 2008. The prevalence of plant food allergies: a systematic review. J Allergy Clin Immunol. 121:1210-1218.
Background: There is uncertainty regarding the prevalence of allergies to plant food. Objective: To assess the prevalence of allergies to plant food according to the different subjective and objective assessment methods. Methods: Our systematic search of population-based studies (since 1990) in the literature database MEDLINE focused on fruits, vegetables/legumes, tree nuts, wheat, soy, cereals, and seeds. Prevalence estimates were categorized by food item and method used (food challenges, skin prick test, serum IgE, parent/self-reported symptoms), complemented by appropriate meta-analyses. Results: We included 36 studies with data from a total of over 250,000 children and adults. Only 6 studies included food challenge tests with prevalences ranging from 0.1% to 4.3% each for fruits and tree nuts, 0.1% to 1.4% for vegetables, and <1% each for wheat, soy, and sesame. The prevalence of sensitization against any specific plant food item assessed by skin prick test was usually <1%, whereas sensitization assessed by IgE against wheat ranged as high as 3.6% and against soy as high as 2.9%. For fruit and vegetables, prevalences based on perception were generally higher than those based on sensitization, but for wheat and soy in adults, sensitization was higher. Meta-analyses showed significant heterogeneity between studies regardless of food item or age group. Conclusion:Population-based prevalence estimates for allergies to plant products determined by the diagnostic gold standard are scarce. There was considerable heterogeneity in the prevalence estimates of sensitization or perceived allergic reactions to plant food.
US Food & Drug Administration, Threshold Working Group, 2008. Approaches to establish thresholds for major food allergens and for gluten in food. Journal of Food Protection. 71(5):1043-1088.
The Food Allergen Labeling and Consumer Protection Act of 2004 (Public Law 108-282) (FALCPA) amends the Federal Food, Drug, and Cosmetic Act (FFDCA) and requires that the label of a food product that is or contains an ingredient that bears or contains a “major food allergen” declare the presence of the allergen as specified by FALCPA. FALCPA defines a “major food allergen” as one of eight foods or a food ingredient that contains protein derived from one of those foods. A food ingredient may be exempt from FALCPA’s labeling requirements if it does not cause an allergic response that poses a risk to human health or if it does not contain allergenic protein. FALCPA also requires the U.S. Food and Drug Administration (FDA) to promulgate a regulation defining the term “gluten free.” This report summarizes the current state of scientific knowledge regarding food allergy and celiac disease, including information on dose-response relationships for major food allergens and for gluten, respectively. The report presents the biological concepts and data needed to evaluate various approaches to establish thresholds that would be scientifically sound and efficacious in relation to protection of public health. Each approach has strengths and weaknesses, and the application of each is limited by the availability of appropriate data. It is likely that there will be significant scientific advances in the near future that will address a number of the limitations identified in this report. The Threshold Working Group expects that any decisions on approaches for establishing thresholds for food allergens or for gluten would require consideration of additional factors not covered in this report. Furthermore, one option that is implicit in the report’s discussion of potential approaches is a decision not to establish thresholds at this time.
Davis, P.A., M. Jenab, J.P. Vanden Heuvel, T. Furlong, S. Taylor, 2008. Tree nut and peanut consumption in relation to chronic and metabolic diseases including allergy. J. Nutr. 138: 1757S-1762S.
The New and Emerging Research session highlighted the emerging understanding of both the positive and negative effects of nuts consumption on health. The limited nature of both experimental and epidemiological evidence for positive relationship(s) between nut intake and health were noted. Study inconsistency and limitations, particularly survey methodology, were explored. Recent results from epidemiologic studies indicating a potential negative association between nut and seed intake and cancer risk were reviewed. The ability of walnuts to reduce endothelin suggests an interesting biochemical mechanism of nut action that may affect other endothelin-associated diseases, which should be further explored. The effects of nuts and their constituents on a nuclear receptor screen (PPAR, β/, , LXR, β, RXR, β, , PXR, and FXR) have been explored. Nut allergenicity and approaches necessary to minimize this effect were also described. In contrast to the positive effects, nut allergies present tree nut-allergic consumers with health challenges. The Food Allergy and Anaphylaxis Network stressed the importance of ensuring that consumers with food allergies have legible, accurate food labels. The Food Allergen Labeling and Consumer Protection Act has engendered precautionary, worst-case allergen scenario labeling statements with unknown benefits to consumer health. Issues of cross-contamination due to shared equipment and shared facilities highlighted the need to rely on allergen control programs that use ELISA technology and have increased understanding of nut allergens. Ultimately, to maximize the positive benefits of nuts, the consumer must be provided with all the information required to make an informed choice.
Vierk, K.A., K.M. Koehler, S.B. Fein, D.A. Street, 2007. Prevalence of self-reported food allergy in American adults and use of food labels. J Allergy Clin Immunol. 119:1504-10.
Background: Few population-based studies in the United States have determined the prevalence of food allergy in adults and the problems these individuals might have with reading food labels. Objective: The objectives of this study are to report the prevalence of self-reported food allergy, to identify the characteristics of food allergy reactions, and to describe the use of labels among adults with food allergy. Methods: Questions from the US Food and Drug Administration’s 2001 Food Safety Survey were analyzed to determine the prevalence of food allergy and opinions about food labels in the management of food allergy. Results: The prevalence of self-reported food allergy is 9.1% among all survey respondents, with 5.3% of all respondents reporting a doctor-diagnosed food allergy. The prevalence of food allergy to the 8 most common allergens (peanut, tree nuts, egg, milk, wheat, soybeans, fish, and crustacean shellfish) is self-reported as 2.7% among respondents with doctors’ diagnoses. Several label issues, such as words on some ingredient lists being too technical or hard to understand and food labels not always alerting persons to new ingredients, were reported as serious or very serious obstacles for managing an allergy. Conclusion: The prevalence of self-reported doctor-diagnosed food allergy among US adults is 5.3%, and a large portion of adults with food allergy found certain label issues a serious problem for managing their food allergy. Clinical implications: The findings provide a needed source of population-based prevalence data of food allergy among US adults. Label issues identified are useful in understanding the difficulties of managing a food allergy.
