How should genetically modified food safety be assessed?

Introduction of new or modified foods, such as genetically modified foods, requires risk analysis since every activity involves risk and in some cases inaction also entails risk.



Work on wheat at the Agricultural Research Institute.

International standards for food safety analysis

At the 26th session of the Codex Alimentarius Commission, held from 30 June to 7 July 2003, landmark agreements were adopted on principles for the evaluation of food derived from modern biotechnology (FAO/WHO, 2003a), and on guidelines for the conduct of food safety assessment of foods derived from recombinant-DNA plants (FAO/WHO, 2003b) and from foods produced using recombinant-DNA micro-organisms (FAO/WHO, 2003c). A fourth document on labelling remains under discussion.

These Codex guidelines indicate that the safety assessment process for a transgenic food should be conducted through comparing it with its traditional counterpart, which is generally considered as safe because of a long history of use, focusing on the determination of similarities and differences. If any safety concern is identified, the risk associated with it should be characterized to determine its relevance to human health. This begins with the description of the host and donor organisms and the characterization of the genetic modification. The subsequent safety assessment should consider factors such as toxicity, tendencies to provoke allergic reaction (allergenicity), effects of changed composition of key nutrients (antinutrients) and metabolites, the stability of the inserted gene and nutritional modification associated with genetic modification. If the entire assessment of these factors concludes that the GM food in question is as safe as its conventional counterpart, the food is then considered safe to eat.

Critics of this comparative approach argue that non-targeted methods that analyse the content of whole foods are needed to assess both intended and unintended effects (ICSU). Scientists generally agree that transgenic foods should be assessed on a case-by-case basis, focusing on the particular product rather than on the process by which it was created. They also agree that the safety of GM foods should be assessed before they are put on the market, because postmarket monitoring is likely to be difficult, expensive and may not yield useful data because of the complex composition of diets and genetic variability in populations (ICSU).

Principles for the risk analysis of foods derived from modern biotechnology

The Principles define modern biotechnology as in the Cartagena Biosafety Protocol, and include principles on risk assessment, risk management and risk communication. The Principles acknowledge that the risk analysis approaches used to assess chemical hazards for substances such as pesticide residues, contaminants, food additives and processing aids are difficult to apply to whole foods. The risk assessment principles clarify that risk assessment includes a safety assessment designed to identify whether a hazard, nutritional or other safety concern is present and, if so, to gather information on its nature and severity. They reflect the concept of substantial equivalence whereby the safety assessment should include, but should not be substituted for, a comparison between the food derived from modern biotechnology and its conventional counterpart. The comparison should determine similarities and differences between the two. A safety assessment should:

 account for intended and unintended effects.

 identify new or altered hazards.

 identify changes relevant to human health in key nutrients. Safety
assessment should take place on a case-by-case basis.

Risk management measures are to be proportional to the risk. These should take into account, where relevant, “other legitimate measures” according to general decisions of the Codex Commission and the Codex working principles on risk analysis (FAO/WHO, 2003d). Different risk management measures can meet the same objective. Risk managers are to account for the uncertainties identified in the risk assessment and manage the uncertainties. Risk management measures could include food labelling, conditions on marketing approvals, postmarketing monitoring and development of methods to detect or identify foods derived from modern biotechnology. The tracing of the product may also be useful for the smooth operation of the risk management measure.

The risk communication principles are premised on the ideal that effective communication is essential in all phases of risk assessment and management. It is to be an interactive process stimulating advice and stakeholder participation. Processes should be transparent, fully documented and open to public scrutiny while respecting legitimate concerns for confidential commercial information. Safety assessment reports and other aspects of the decision-making process should be available to the public. Responsive consultation processes should be created.

Guideline for the conduct of food safety assessment of foods derived from recombinant-DNA plants

The Guideline for the conduct of food safety assessment of foods derived from recombinant-DNA plants was also adopted by the 26th session (July 2003). The Guideline is designed to support the Principles for the risk analysis of foods derived from modern biotechnology. It describes the recommended approach for making a safety assessment of foods derived from recombinant-DNA plants where a conventional counterpart exists. A conventional counterpart is defined as “a related plant variety, its components and/or products for which there is experience of establishing safety based on a common use as food”. The techniques described in the Guideline may be applied to foods derived from plants that have been altered by techniques other than modern biotechnology.

The Guideline provides an introduction and rationale for food safety assessment of recombinant-DNA plants, drawing distinctions between it and conventional toxicological risk assessment for individual compounds that rely on animal studies. The “goal of the assessment is a conclusion as to whether the new food is as safe as and no less nutritious than the conventional counterpart against which it is compared”. The Guideline indicates that substantial equivalence is not a safety assessment per se. Rather, it represents a starting point to structure food safety assessments relative to a conventional counterpart. Substantial equivalence is used to identify similarities and differences between the new food and the conventional counterpart. The safety assessment then assesses the safety of identified differences, taking into consideration unintended effects resulting from genetic modification. Risk managers subsequently judge this and design risk management measures as appropriate.

Guideline for the conduct of food safety assessment of foods produced using recombinant-DNA micro-organisms

This Guideline is also intended to provide guidance on the safety assessment procedure of foods that are produced by using recombinant-DNA micro-organisms, based on the risk assessment framework of the above-mentioned Principles. The interesting point in the case of recombinant-DNA micro-organisms is that the comparison is recommended not only between the recombinant-DNA micro-organisms and their conventional counterparts (micro-organisms) but also between the foods produced by using them and the original foods.