In Europe the public demanded identifying labels or restrictions on such crops. The crops have not been tested using animal studies and studies with human volunteers as is required for pesticides and pharmaceutical drugs. GM crops are present in most of the processed foods marketed in North America. A mild-mannered Hungarian, Arpad Pusztai, immigrated to Scotland and rose to become a world authority in the important field of plant lectins at the Rowett Research Institute in Aberdeen, Scotland. Plant lectins are proteins that bind to sugar molecules that form part of the cell surface of mammalian cells and are involved in signaling for cell growth and metabolism.
Lectins are also toxic to pests that browse on the plants.
Dr. Pusztai shook the world of genetic engineering to its very foundation when he fed rats potatoes that had been modified with a lectin gene from the snow drop flower. Even though some lectins are highly toxic to humans, the developers of the GM potato believed that it would be toxic to insects, nematodes and fungi without harming mammals. To his surprise and alarm Dr. Pusztai found that rats fed the GM potato suffered damage to their immune system and digestive system. The experiments commenced in 1995. During 1996 and on many occasions later Pusztai warned the Ministry of Agriculture of his growing concerns and in 1998 he warned government inspectors.