The following are the concerns over GM foods from green groups and consumer groups –

Health concerns over human consumption of GM foods/crops

Allergic reaction

The random integration of the target gene into the host plant DNA as a result of the genetic engineering processes leads to the concern that new allergens may be synthesized in GM foods and cause allergic reactions in susceptible individuals. Although there is a theoretical possibility that new allergens may be expressed in the food, allergenicity is included in the safety assessment of GM foods before the products are launched on the market. Such assessments could help to exclude GM foods that are likely to be allergenic from entering the market.

Gene Transfer

In the process of genetic modification, antibiotic resistance genes are used as markers for identification of successful gene transfer. There are concerns about the possibility of transferring these genes from GM foods to the bacteria in the human gut that leads to the development of antibiotic resistance in these bacteria. Such gene transfer is considered a rare possibility because many complex and unlikely events would need to occur consecutively for this to happen. Nevertheless, the World Health Organization (WHO) and the Food and Agriculture Organization (FAO) have advised the industry not to use marker genes carrying information of resistance to antibiotics that are frequently prescribed for therapeutic purposes.


Outcrossing, which refers as the movement of genes from GM plants into conventional crops or related species in the wild, as well as the mixing of crops derived from conventional seeds with those grown using GM crops, may have an indirect effect on food safety and food security. The World Health Organization (WHO) described outcrossing as a real risk, as was shown when traces of a maize type which was only approved for feed use appeared in maize products for human consumption in the U.S. Several countries have now adopted strategies to reduce mixing, for example, by making a clear separation of the fields within which GM crops and conventional crops are grown.

Environmental concerns over the release of GM crops to the environment

Social and ethical concerns