One critical problem with GMOs is the health effects that may arise. Critics fear there may be a development in toxic proteins, in company with a development of new allergens, within GM foods. These are termed as "Frankenstein foods" because of the unforeseen adverse health effects on their consumers. This transferring of antibiotic-resistant genes to human gut bacteria can be a very damaging effect.

Another problem currently arising in many areas is that genetically modified crops are becoming insidious super weeds. These genetically modified crops are accidentally breeding with wild plants, or other crops, and genetically polluting the environment. According to Greenpeace, in a 2002 study, trans-genes had spread from US to traditional maize varieties in Mexico. Also found in a 2004 study was that conventional varieties of major US food crops have also been widely contaminated by this effect.

GMOs treated for insect-repelling qualities may speed the evolution of insecticide-resistant pests, which in turn will call for the development of more hazardous and deadly insecticides.

Farmland biodiversity may also be affected by the growing GM crops according to environmentalists. Farmland biodiversity is critical to the continuing development of plants resistant to new pests, diseases, and changing environmental conditions. Without this genetic diversity, several problems can arise and actually can be linked to many of the major crop epidemics in human history.

Lobbying and deep pockets are keeping the public blind about GMOs. We have been denied the right to know about GMO ingredients in the food chain, and are seldom even told if the food is genetically modified; therefore, we don't have the right to avoid them.

According to Greenpeace, Farmers in North America and Latin America, where most of the world's genetically engineered agriculture is, must sign a contract that specifies that if they save the seeds to plant again the following year or use any herbicide other than the corporation's own, they are likely to be prosecuted