A brief on the potential allergenicity and safety assessment of genetically modified crops.
Public awareness and concern about food allergens are growing. Allergenic reactions to proteins expressed in GM crops have been one of the prominent concerns among biotechnology critics and concern of regulatory agencies.
Allergen
An allergen is a protein that triggers a hypersensitive immune response, a property known as allergenicity. These proteins are small, resistant to heat and acid, and can survive stomach enzyme degradation. They may cause atopic reactions such as hives, other skin responses, or gastric distress, and severe reactions can lead to death from anaphylaxis. Although staple crops contain tens of thousands of proteins, only a few are allergenic. Genetic engineering may alter the allergenic potential of crop plants. GM crops can acquire allergenic proteins if the transgene comes from a known allergenic source. For example, an experimental GM soybean engineered to contain a Brazil nut methionine-rich protein triggered allergic reactions in sensitive individuals and was subsequently withdrawn from development. Strict measures are required to prevent the introduction of allergens into new crops.
Inserting a gene can cause unintended effects by altering the expression of endogenous genes, leading to overexpression or underexpression of specific proteins. If the host plant contains known allergens, adding a new gene may increase allergen levels, making the plant more allergenic. The DNA insertion can also create new proteins that trigger allergic reactions in susceptible individuals. Predicting whether any protein will be a food allergen is difficult. The World Health Organization developed a decision tree to assess potential allergenicity by evaluating characteristics such as sequence similarity to known allergens and protein stability during gastric digestion. However, this decision tree serves only as a guide and cannot reliably predict allergenic potential or potency. An example decision tree for novel foods is shown below.
Safety Assessment of GM Food
Besides allergenicity, genetic modification might also alter the toxicity and chemical composition of a transgenic plant.
- Considering both intended and unintended effects of genetic modification, the Codex Alimentarius Commission has issued guidelines for the safety assessment of GM foods.
- While no such foods are currently on the U.S. market, the FDA reminded developers transferring genes for known food allergens—including major allergens like milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, sesame, and soy—of the relevant legal requirements.
- According to the FDA, developing GM plants with a transferred allergen requires enhanced stewardship and risk management.
- Standard mitigation practices, such as crop segregation, must be strengthened to prevent accidental mixing with other foods and ensure food safety.
To know more about allergens please click on the given link –
Developers must ensure that allergenicity information for any crop containing a transferred allergen remains linked to that specific allotment throughout the supply chain, including seed development, planting, harvesting, storage, transport, and processing. This ensures that the allotment is not confused with or used as a non-allergenic counterpart. Developers are responsible for marketing safe, properly labeled food and for complying with the requirements of the Federal Food, Drug, and Cosmetic Act (FD&C Act).