Some genetically-modified foods that are on sale for public consumption include tomatoes and cantalopes that have modified ripening characteristics, soybeans and sugarbeets that are resistant to herbicides, and corn and cotton plants with increased resistance to insect pests. Not all these products are available in supermarkets yet; however, the prevalence of GM foods in U.S. grocery stores is more widespread than is commonly thought. While there are very, very few genetically-modified whole fruits and vegetables available on produce stands, highly processed foods, such as vegetable oils or breakfast cereals, most likely contain some tiny percentage of genetically-modified ingredients because the raw ingredients have been pooled into one processing stream from many different sources. Also, the ubiquity of soybean derivatives as food additives in the modern American diet virtually ensures that all U.S. consumers have been exposed to GM food products.
For more information on Genetically-Modified Foods please visit:
Sources
Genetically-Modified Foods: Harmful or Helpful? at http://www.csa.com/discoveryguides/gmfood/overview.php
U.S. Department of Agriculture at http://www.ers.usda.gov/briefing/biotechnology/