Japan granted approval in January 2021 for the first ‘CRISPR tomatoes’ to be used in food production. Compared to conventionally-bred tomatoes, the CRISPR tomatoes contain a much higher concentration of a plant compound (GABA). GABA (γ-Aminobutyric acid) can decrease the transmission of specific signals in the central nervous system which may, amongst others, result in lower blood pressure. The tomatoes will, therefore, be introduced as a modern ‘lifestyle’ product. At the same time, it is known that GABA has a multifunctional role in tomato plants: it influences, for instance, plant growth, resistance to plants pests and diseases as well as several other metabolic responses. According to the information available, the tomatoes were neither examined for intended effects nor for any potential unintended health effects.
The concentration of GABA is naturally enhanced in plants that are attacked by pest organisms. However, all attempts to achieve a permanently higher level of GABA in the plants through conventional breeding have failed. Due to the multifunctional role of GABA, it has to be assumed that the genetic intervention will affect plant metabolism on several levels. These changes may also cause unintended health effects when consumed. In addition, the plants can show unexpected responses to environmental stress conditions, which can then impact the safety of food products.
This example shows how major changes in the composition of food plants can be achieved without inserting additional genes. The NGT processes can cause extreme variants of biological characteristics as well as new traits which are unlikely to be achieved with conventional breeding. Unintended effects may occur due to interactions in the complex networks of genes, proteins and other biologically active molecules. Such unintended effects can still emerge even in cases where the genetic intervention is targeted and precise. Therefore, genetically engineered plants need to be thoroughly investigated before any conclusions can be drawn on health and environmental risks or safety.