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solved; however, a number of new strategies have been developed. Of course
the ultimate approach to solving these problems may be to transplant the
gene s coding for the needed proteins directly into human cells. Similar strate-
gies have been used in cows to allow them to produce hormone drugs in their
milk. There are ethical, moral, and religious concerns with these approaches.
This is the topic of another book!
Based upon this brief introduction to a small part of the world of biotech-
BIOTECHNOLOGY AND GENETICALLY MODIFIED FOODS 129
nology, I hope that the reader can now appreciate the potential promise it
holds for reducing or even completely eliminating the need for synthetic
insecticides or herbicides in the future. If chemophobia continues to take
hold in the minds of society, then biotechnology should be the logical alter-
native to develop approaches to replace pesticide use in agriculture. The
potential also exists for reducing the concentrations of endogenous plant tox-
ins that is, all those nasty poisons, like caffeic acid, that we discussed in
Chapter 5 and boosting the level of beneficial vitamins and compounds,
such as antioxidants, in fortified produce grown for humans. Despite these
promises, biotechnology is consistently attacked in the same breath as chem-
ical pesticides. Because of the public s perception that all technology may be
tainted, biotechnology already has a stigma in the public s eye. Before I
address what I perceive to be the overall reason for this concern, what are the
potential problems associated with plant biotechnology? What are the risks,
and how much do we know about the potential hazards?
There are two levels of concern relative to transgenic plants. The first is in
the realm of toxicology and is similar to that of any pesticide product, which
is to insure that the plant itself is nontoxic to humans. The second relates to
the genetics and concerns whether the genes that have been transferred to
these new hosts could ever leave and transfect other plants or even different
life forms. The first concern is in the realm of food safety, and I believe can be
addressed with existing technology. The second is in the realm of ecology, and
data is lacking to address many of these issues. Again, I must stress that the
coverage in this book is focused on chemical food safety and not ecology.
There may be reasons that bioengineered plants should not be introduced
into the environment. However, arguments about their inherent food safety
should not be used out of context.
The toxicology of transgenic plants relates to whether the proteins
expressed by the inserted genes the compounds which kill the plant
pests are dangerous to humans eating them. Most of these are protein
products expressed in areas of the plants that are not normally eaten by
humans, but the genes are present in the edible components. Because they
are proteins, as discussed in the BST chapter, most would be digested along
with the rest of the plant. However, some work has indicated that some
forms of Bt proteins in corn are more heat stable and resistant to digestion
than other proteins. This would allow them to persist in human diges-
tive tracts. Since they are proteins, they still could not be absorbed. However,
as will be discussed below, they could prove to be allergens to sensitive
individuals.
It is conceivable that new, nonprotein compounds could be produced by
these hybrid plants that could also be toxic to humans consuming them.
Alternatively, it is possible that some manufacturers could get sloppy and
130 CHAPTER 9
inadvertently carry other genes along which would contaminate the genome.
To test for this, existing regulations require that these plants undergo safety
testing. These well-established toxicology protocols, which are used to weed
out toxic drugs and pesticides, would detect bioengineered plants that
expressed toxic proteins and chemicals. Curiously, plants produced using
classical breeding techniques, which have the potential to carry along some
true deleterious genes, are not required to be tested. Does this treatment pro-
mote the public health?
Biotechnology is more selective in the manner in which plant characteris-
tics are controlled. Because new products must undergo batteries of toxicity
tests before regulatory approval, the products approaching market are safer
than most other plant-derived produce developed using conventional agricul-
tural techniques.
There is a concern shown in recent evidence with Bt corn that insect pests
targeted by these gene products may develop resistance to the products, thus
making them ineffective. This is identical to the resistance seen against nor-
mal organic pesticides. However, this is part of the natural process of adapta-
tion and natural selection and is no different from the adaptation seen over
eons of evolution or with pesticide usage. One strategy for handling this is to
build different combinations of such toxins into the plants to discourage
development of resistance, a strategy that is conceptually similar to that used
in preventing antibiotic resistance in bacteria or drug resistance in AIDS.
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