On Food and Cooking

animals by surgically precise manipulation
of the DNA that makes up their genes. This
manipulation bypasses the natural barriers
between species, so theoretically a gene
from any living thing, plant or animal or
microbe, can be introduced into any other.
Genetic engineering is still in its
infancy, and to date has had a limited
impact on the foods we eat. In the United
States, an estimated 75% of all processed
foods now contain genetically modified
ingredients. But this remarkable figure is
due to just three agricultural commodities
— soybean, canola, and corn — all of them
modified for improved resistance to insect
pests or herbicides. As I write in 2004, the
only other significant engineered U.S. crop
is Hawaiian papaya, which is now resistant
to a formerly devastating virus disease. A
few other foods are processed with
enzymes made in engineered microbes —
for example, much cheese is coagulated