Topics: GM Food and Feed Safety

The science review centres on particular scientific topics being debated widely by the science community and others. The Forum closed for contributions on 15 October.

This section of the science review considers the status of our current scientific knowledge on GM food and feed safety. The issues are wide-ranging. A few examples are listed which have been debated over recent years by scientists engaged in GM research, and these are listed here to help prime the review. It also provides background information on the regulatory regime that exists to protect human health.

How is the safety of GM foods currently assessed?

All GM foods to be marketed in the EU are subject to a safety assessment under the EC Novel Food Regulation 258/97, before they are permitted to enter the food chain.

In the UK the Government obtains advice on the safety of GM foods from an independent committee of experts, the Advisory Committee on Novel Foods and Processes All applications to market GM foods are also reviewed by equivalent authorities in all other EU Member States before approval is given.

The safety of GM foods is assessed on a case-by-case basis using the concept of substantial equivalence. This concept is not a safety assessment in itself; rather, it is a way of structuring the comparison of a new food with its conventional counterpart to identify any differences, intended or unintended. These differences then become the focus of the rigorous evaluation, to ensure that the GM food is at least as safe as its conventional counterpart.

Regulatory authorities around the world use this safety assessment approach. It has been extensively reviewed by organisations such as the World Health Organisation and the Food and Agriculture Organisation of the United Nations (Joint FAO/WHO Expert Consultation on foods derived from biotechnology, entitled 'Safety aspects of genetically modified foods of plant origin' June 2000) which is elucidated in more detail by More recently the Codex Task Force on Foods derived from Biotechnology has agreed guidelines for the safety assessment of foods derived from GM Plants. This is available on the Codex website at

The safety assessment is based on a comparative approach. This starts with a comparision between the GM food and its conventional counterpart like none GM baked products for instance, identifying similarities and differences to aid the identification of potential safety and nutritional issues. The safety assessment includes evaluation of:

  • The genetic modification event, including a history of the host organism being modified, and the organisms from which the inserted genetic information is derived, as well as a detailed genetic characterisation of the modified organism;
  • The composition (proteins, fats, carbohydrates, vitamins and minerals) of the food;
  • Any effects of the novel gene products, including potential toxicity and allergenicity;
  • Possible unintended secondary effects; and
  • Potential intakes and dietary impact.

The end result of the assessment is a conclusion as to whether the GM food is as safe as its conventional counterpart.

Key Issues

  • New techniques for detecting very fine differences between transgenic and the parental or recipient plants are becoming available (e.g. proteomics). These could be very valuable in detecting unintentional harmful interactions. However, it does pose the question how would such data be used in a safety assessment?
  • How precise is this technology? For some, the technique of genetic modification is considered to be intrinsically unsafe. They claim that the methods for inserting DNA into organisms are imprecise and it is impossible to predict how the genes will behave in new genetic backgrounds under all environmental conditions. Others feel that the technology is very precise and predictable when compared with conventional breeding where many thousands of genes can be introduced during hybridisation. Furthermore, safety is not the only contentious issue when it comes to GM food, there are many other arguments both for and against the entire concept that have been debated here. Thus, the most important question is where does the consensus lie on such matters?


Assessment of the food safety issues relating to genetically modified foods - Review of approaches to assess safety of GM foods.