CONSIDER the cautionary tale of the celery. In the mid-1980s, celery growers in the US introduced what they thought was a wonderful new strain. Highly resistant to insects, it promised to boost yields dramatically. There was just one small problem. People who handled the celery sticks began complaining of severe skin rashes. Dermatologists discovered that the celery was shedding psoralens, natural chemicals which become irritants and mutagens when exposed to sunlight.
Or take the once notorious American Lenapeor rather, don't. All seemed well with this hardy new variety of potato launched in the US and Canada in the 1960s. Then came the bitter truth. Biochemists discovered the source of the tuber's unusual burning flavour: dangerous levels of toxins called glycoalkaloids.
"Many nightmares predicted for genetically engineered crops have already happened," reflects Tony Conner of the New Zealand Institute for Crop and Food Research near Christchurch. It's just that "not many ...
To continue reading this article, subscribe to receive access to all of newscientist.com, including 20 years of archive content.