The simple answer is that 20+ years of composition assessments of GMO crops have demonstrated that crop composition is not appreciably affected by the GM process (1). In addition, data collected through that time have indicated that general factors such as the growth environment can contribute to notable variation in component levels (2).
Plant agglutinins (or lectins) and amylase inhibitors are examples of anti-nutritional compounds that may be present in crops. The relevance of such a compound is a characteristic of a crop; some crops contain appreciable levels, while others do not. Where needed, specific processing approaches, such as heating, are used to deactivate or remove anti-nutrient compounds and enable safe use of the crop products.
For a number of crops, the Organisation for Economic Cooperation and Development (OECD) has developed documents that review common uses of the crop and suggest the key components to be assessed for GM varieties. Those components encompass the key nutrients, toxicants, and anti-nutrients for that crop. Thus, for a crop where lectin or amylase inhibitor is considered a key anti-nutrient, for example, lectin in soybean, that compound is typically assessed in a GM variety.
- Herman and Price, 2013, Journal of Agricultural and Food Chemistry, 61:11695. Unintended Compositional Changes in Genetically Modified Crops: 20 Years of Research.
- Harrigan et. al., 2010, Nature Biotechnology, 28: 402. Natural Variation in Crop Composition and the Impact of Transgenesis.