Scientific Projects

Benefits and Risks of Genetically Modified Foods for Human Health and Nutrition

Human health is not achievable unless adequate amounts of nutritious and safe foods are available and accessible during all life stages. An estimated one-third of the world’s population, largely in the developing world, is currently food and nutrition insecure. The biologic imperatives for achieving nutrient and food security, as well as humanitarian concern, are the driving forces behind efforts to achieve equitable food distribution among today’s global population. Food systems, therefore, are challenged to meet current global needs and those of the future in the light of mounting population pressures and rising quality-of-life expectations, while recognizing increasingly limited arable farm resources. A principle assumption is that the resolution of food and nutrition problems and challenges of today and tomorrow have technological dimensions. Transgenic modification (GM), traditional and modern, applied to plant and animal food sources (GMFs) hold potential for improving human nutrition and health provided that the capabilities for using GM crops are available in the developing as well as the developed world. Coexisting with potential benefits of genetic modifications of plants and animals are known and unknown risks, as is common to all technologies, old or new. Implicit in the latter assumption is that absolute safety is not an achievable standard.

Public discussions surrounding the development and use of applications of modern biotechnology for agriculture are widespread, particularly discussions about the development of GMFs and GMOs and the safety and efficacy of the new products. Public concerns about gene technology lie in four major areas, namely ethical concerns, socio-economic issues, effects on the environment and food safety and human health. Although acknowledging the importance and the interconnectivity of all these areas, the principal focus of this statement is the scientific basis for assessing the risks and benefits to human health of GMFs and GM crops.

ICSU, recognizing that the context in which choices are made varies significantly with differences in societies, environments and economies across the world, takes no position on appropriate policies that societies should adopt relative to GM food crops based on a review of the scientific knowledge of benefits and risks currently available. The only assertion made is that the technological dimensions of GM crops merit consideration along with others, for example economic policies such as those that govern global trade and agricultural subsidies.

Traditional breeding techniques, which genetically modify plants and animals, have led to documented contributions to human nutrition and occasionally to unintended health risks. Transgenically modified plants and animals are projected to give rise to benefits and risks in two broad areas: health and the environment. Four categories of health benefits are recognised: enhancement of food security; enhancement of nutrient security; more targeted health benefits, such as immunisation; and reduction of diet related, adult-onset chronic diseases (through the manipulation of specific food components, e.g. manipulation of fat composition). Health risks associated with the approaches that are reviewed generally also fall into four categories – allergies, toxicities, nutrient imbalances, and decreasing diet diversity.

Food Quality and Human Nutrition

Most consumers in rich countries have access to a relatively inexpensive supply of safe and healthy food. In contrast, micronutrient malnutrition is widespread in poor countries, affecting more than one-half of the population in the developing world. The potential benefits of improving the nutritional quality of foods are higher for low-income countries, where food budgets account for two-thirds or more of total expenditures. The sustainable solution to malnutrition in developing countries is provision of a sufficient quantity of high quality diet. Nutritional and quality traits of foods can be altered through transgenic methods; such biofortification is a low-cost strategy for improving food quality that complements other technological and social interventions. The nutritional efficacy and risks of unintended harmful effects of these products have yet to be tested and demonstrated.

Agricultural Practice

Developments in agricultural biotechnology are being used to increase the productivity of crops, primarily by reducing the costs of production. These new crop varieties include insect resistance (cotton, maize), herbicide resistance (maize, soybean), delayed fruit ripening (tomato). The estimated global area of transgenic crops (predominantly with agricultural benefits) for 2001 is 52.6 million hectares grown by 5.5 million farmers in 13 countries. More than one quarter of the transgenic crop area in 2001 was grown in six developing countries. The number of farmers that planted GM crops increased from 3.5 million in 2000 to 5.5 million in 2001.

GMF crops could decrease the cost of production and have positive effects on the environment in both developed and developing countries. The development of crops resistant to biotic and abiotic stresses is critical for sustainable food production in the developing world. The use of GMF crops should go hand-in-hand with other technologies such as plant tissue culture, marker-assisted breeding and conventional plant breeding. It is, however, prudent that the outcomes and impacts of the use of GMF crops are scientifically monitored with respect to farming efficiency, food production and environmental impacts.

Industrial Products and Processes

Crops can be genetically modified to produce oils, starch, fibre, protein or other chemicals useful for industrial processes. For example, soybean oil, with high oleate content, and canola oil, rich in laurate, are both being produced commercially using these methods. A principal concern is how to use genetic modification technology in a way that gains the advantage of using renewable resources to replace products from petroleum and other non-renewable resources while maintaining a safe and adequate human food supply. It is also crucial to ensure that GM crops designed to produce industrial products do not inadvertently enter the human food chain or contaminate food crops with their transgenes, if these traits may pose a risk to the environment or to human health.

Fish

Many species of fin fish have been subjected to genetic modification. The present and projected increasing demand for fish suggests that GM fish may become important in future in both the developed and developing worlds. However this will only be possible if consumer acceptance is achieved. No GM fish is known to be produced commercially for food at present, although some are being considered for the food market, and for some regulatory approval is pending.

Livestock and Poultry

Food products derived from GM livestock and poultry are far from commercial use. The methods involved are presently inefficient and expensive. Potential hazards to humans involved in production or when products become part of the food chain, will require careful assessment. There are serious public concerns about the ethics of manipulating domesticated animals and the possible welfare effects Microorganisms. No genetically modified microorganism is currently used in foods although some are used to produce food ingredients. The safety evaluation of GMM-derived food additives and processing aids should place special emphasis on the detection of possible unintended effects.

Regulation and Risk Assessment

The process of the development of transgenic organisms presents no new categories of risk compared with conventional methods for improving plants, animals or microorganisms. However, specific traits introduced by either approach might pose unique risks, which need to be identified.

The Organisation for Economic Co-operation and Development (OECD) and the World Health Organization (WHO) in collaboration with the UN Food and Agriculture Organization (FAO) have published regulatory guidelines for GM foods.

Safety assessment of GM foods is carried out on a case-by-case basis, taking the specific modification features into account, and comparing the properties of the new food with those of the traditional counterpart. This comparative approach (substantial equivalence) is based on the assumption that conventional foods are generally considered as safe for consumption and is a starting point for a safety evaluation. Identified differences between the GM food and its counterpart are assessed with respect to their safety and nutritional implications for the consumer.

Present approaches to detecting changes in the composition of GM food crops are primarily based on measuring a limited selection of single compounds. A non-targeted approach using new gene expression technologies can be used. Safety testing of whole GM foods needs improvement.

Socio-Economic Aspects Relevant to Sustainability

Currently available GMOs may have both positive and negative effects on three indicators of sustainable agriculture and rural development, namely stocks of natural resources and environmental capital, efficiency and equity. Three policy options are key to the sustainable development, use and control of GM foods, namely intellectual property protection, trade liberalisation and biosafety implementation. The effects of policy options that shape socio-economic conditions are intricate; a policy option that directs socio-economic conditions in one way may affect another policy option that leads in a different direction.

Societal Issues and Public Attitudes

Public perceptions and attitudes about emerging biosciences and other new technologies are critical determinants of how likely it is that the implementation and development of such technologies will succeed. While it is important to develop best practice in science communication pertinent to the risks and benefits of GMFs, this alone will not increase public confidence in gene technology. Rather, it is also important to consider new ways to involve members of the public explicitly in the debate about technology innovation and commercialisation and to improve the relationship and dialogue between science and society.