CRISPR-Tomatoes: Combinatorial effects can jeopardise food safety

NGTs are currently being used to change the agronomic and health-related properties of tomato plants. These developments are anticipated within a few years. In contrast, conventional methods sometimes require decades of breeding or are simply not possible. The improved composition and physiological properties of the NGT tomato plants are expected to make them particularly healthy and sustainable.

There are currently a number of projects aiming to improve tomato plants: for example, several genes were knocked out in a wild tomato variety to change growth habit, composition as well as the number, size and shape of the fruits. However, because the composition of the ingredients in these tomatoes is so different compared to commercially available tomatoes, the European Food Safety Authority (EFSA) identifies the need for risk assessment of these NGT plants.

Other NGT tomatoes have been developed to have a higher concentration of vitamins or blood pressure-lowering properties. GABA tomatoes were one of the first NGT plants to be brought to market; they are sold in Japan as a lifestyle product. However, these tomatoes were not tested by the authorities for ‘risks and side effects’ before being authorised. GABA in plants is essential in a variety of metabolic pathways, and an altered GABA content can, therefore, influence environmental interactions as well as other ingredients in the tomatoes and their physiological compatibility.

Further objectives of new genetic engineering relate to the cultivation and harvesting of tomatoes. Some of the products that could be commercialised in the next few years include ‘easy to pick tomatoes’ (easier harvesting), ‘small bushy tomatoes’ (particularly suitable for ‘urban gardening’) or ‘vitamin D tomatoes’ (increased vitamin D content).

Apart from food safety, the risks associated with NGT tomatoes include interactions with the environment (such as interactions with pollinators or soil organisms) and sensitivity to environmental stress.

Many NGT tomatoes could soon be grown and sold for consumption. They could then, for example, be mixed into salads without first being tested for maximum dosage or combinatorial effects. At present, different tomato varieties can be arbitrarily combined in tomato salads or otherwise combined with different foods. In future, NGT tomatoes with an increased vitamin content could, for instance, cause problems if they are eaten in combination with other foods containing vitamins or with food supplements. In addition, mixing genetically engineered tomatoes, e. g. with a higher content of GABA, vitamin D or other physiologically-active ingredients, raises new questions about food safety, especially in regard to their long-term effects. Other undesirable changes in the composition of the fruits should also be taken into account, as some of these are so complex that the overall effects are difficult to assess.

Even if individual tomato varieties are considered safe, new uncertainties and risks may arise from the combination of their properties. Therefore, a mandatory approval process will continue to be necessary in the future, including risk assessment of the individual NGT tomatoes and investigation of possible combinatorial effects in relation to potential environmental interactions or other NGT organisms.

Further information:
TA report
NGT tomatoes
RAGES report

This site is registered on as a development site. Switch to a production site key to remove this banner.