The allergenicity of genetically modified foods from genetically engineered crops
The following is an introduction and conclusion of a study published in the journal Annals of Allergy, Asthma & Immunology assessing the claim that GMOs can cause allergies.
During the past 2 decades, the diagnosis of food allergy has increased in industrialized countries. Immunoglobulin E (IgE) food allergies affect an estimated 4% to 8% of the American population.1,2 The reason for this increase remains unclear, but food allergy has become an increasingly difficult challenge for patients and their physicians to manage. Repeated exposures lead to significant morbidity, life-threatening anaphylaxis, and substantial health care costs. Because proteins are the primary precipitant of many allergic reactions, some members of the public have become concerned that the proteins produced in genetically modified (GM) crops will lead to an increase in allergic reactions in people who consume those crops. Others have made claims that these products have directly caused or contributed to the overall increase in food allergies. In addition, people worry that the introduction of a gene might increase the levels of allergenic proteins in these plants. This article describes how GM crops are produced, how GM crops are tested, and how allergies are tested and future directions for testing and GM products and presents a systematic review on GM products and their potential for allergenicity
Based on the data to date identified in this systematic review, we conclude that, in reference to the first query, GM products do not appear more allergenic than their conventional counterparts as determined by IgE binding studies in well-characterized sera from humans with allergy and animal models, case series of direct provocation and ingestion, and simulated digestion studies. These are methods approved by the World Health Organization for determining allergenicity of GM products.13 We did identify limited evidence that genetic modification, in some instances, resulted in the product having decreased IgE binding capacity in subjects with allergy compared with its conventional counterpart, which could indicate hypo-allergenicity, although this concept requires more robust study. It is important to emphasize that known allergens to an individual, be it in a GM form or conventional form, will still be allergenic in that individual and it should be avoided. This review also highlights that there is no evidence that eating GM products in individuals who are not allergic to conventional forms of those items would result in allergy or increase the risk of developing an allergy to that item.
For the second query, there were no animal or human studies identified that evaluated the effect of the consumption of GM products and the overall risk of developing a food allergy or other allergic disease. Thus, given no controlled studies and no proven medical evidence to support or refute an association between use of GM products and the development or risk of developing food allergies, no data outside the NAS report conclusion are available to evaluate this hypothesis.3 This would represent a knowledge gap where future study could be highly informative. In conclusion, although individuals with allergy should avoid conventional and GM forms of that particular food, GM foods do not appear to be more allergenic than their conventional counterparts, and no data exist that consumption of GM proteins causes allergy to develop to that particular food in individuals who are not allergic at baseline.
To read the entire study, please visit the Annals of Allergy, Asthma & Immunology journal website.