Re: what is genetically modified foods

Genetically modified food is derived from genetically modified organisms 
(GMO). The genetic blueprint of these organisms, mostly crop plants, has 
been changed by the introduction of foreign genes through genetic 
engineering, to improve particular traits such as resistance to 
environmental stress (drought, heat, cold), pests or herbicides. Other 
efforts are geared towards improving the performance of crop plants after 
harvest, increasing their nutritional value or producing specialty 
products.

Here are some examples:

There is a genetically modified tomato variety that was marketed under the 
name Flavr Savr. Particularly during the winter months, tomatoes you see 
in grocery stores come from Florida, California or Mexico. They were 
picked while still green and firm and transported in refrigerated trucks 
to their destination, where they are gassed with the fruit-ripening gas 
ethylene and develop the red color. However, since the flavor of these 
beautiful red tomatoes never fully developed, they have little taste. In 
the Flavr Savr tomato, the gene for the protein that brings about 
softening of ripe tomatoes was inactivated, by introducing a copy of the 
gene in the opposite orientation. As a result, the Flavr Savr tomato 
produces very little of this protein, and its tomato fruits soften very 
slowly. Therefore, tomatoes can be left on the vine longer to develop 
their flavor and taste better. The Flavr Savr tomato has since been taken 
off the market since it proved to be too expensive to produce.

Rice is a staple food in many developing countries, where people often 
subsist on one meal of rice per day. Unfortunately, rice does not contain 
provitamin A (= beta-carotene), a yellow pigment found in carrots and 
other plants. Humans can convert the beta-carotene that they eat to 
vitamin A, but cannot make their own. Vitamin A deficiency is the leading 
cause of blindness in developing countries, and is accompanied by 
increased susceptibility to a variety of diseases. Recently, scientists 
have genetically engineered rice to produce provitamin A in amounts that 
are almost sufficient to meet the recommended daily requirements for this 
vitamin with one meal of rice. This genetically engineered yellow rice 
will be made available to farmers in developing countries at no cost.

Another exciting area of research is the development of edible vaccines in 
plants (no more shots!). Potatoes have been genetically engineered to 
carry a gene from the diarrhea-causing bacterium Escherichia coli and to 
produce the bacterial protein in their tubers (i.e. the parts of the 
potato that we eat). People who ate raw potato tubers from these plants 
developed antibodies against the bacterium, suggesting that one can be 
immunized by simply eating fruits and veggies that produce the appropriate 
vaccines. Since cooking would destroy the bacterial protein and raw 
potatoes are not considered delicious food by most people, scientists are 
now working on genetically modifying bananas, instead. If successful, 
these vaccine-carrying bananas would provide a convenient way of 
immunizing children, particularly in developing countries.

For news releases/information about the provitamin A-producing rice, the 
Flavr Savr tomato and other examples and issues related to genetically 
modified food, look up these sites:
 http://news.bbc.co.uk/hi/english/sci/tech/newsid_602000/602112.stm http://www.nbiap.vt.edu/news/1997/news97.aug.html#aug9703 http://www.fda.gov/bbs/topics/NEWS/NEW00482.html http://birch.cit.cornell.edu/ar96/ar96.biotech.html