Genetically modified food has become a highly
politicised, emotional issue with heated
arguments and accusations between those for
and against their use.
South Africa produces GM crops like maize,
soybean and cotton. These crops have been
modified by adding a gene that gives the plant
resistance to a herbicide or pest. This gives the
crop a better chance of growing and hopefully
improving its yield.
The promise of genetically modified crops is that
any gene can be introduced to give a plant better
characteristics. Not only are disease or drug
resistant plants being grown, but others are being
developed to produce nutrients that might be
lacking in staple foods - like vitamin A in Golden
rice.
Because we eat these crops, there are concerns
about their safety. Accusations of foul play by big
corporations and of guerrilla tactics by anti-GM
groups have polarised this issue in the media.
Most of these concerns are blown out of
proportion - fed by the idea that our interference
with genes is unnatural.
Farmers have been interfering with genes for
centuries by cross-breeding plants to improve
crop yield or resistance against diseases and
pesticides. The difference with GM foods is that
this process is highly selective. Rather than
crossing two plants and hoping that a mixing of
all their genes will bring out a better result, a
single gene gets changed in a GM plant. Scientists
who make GM plants also check that the gene is
in the right place, that it works correctly and that
it does what it is designed to do. This means that
GM plants are often better understood than
traditionally farmed crops.
The concerns of those opposed to GM foods is
that this might decrease the diversity of the crop,
that GM plants are grown in a way that makes
them less healthy with less nutrients than their
unmodified versions. The two biggest concerns
are the safety for animals and humans who eat
the crops and the environmental safety of the
crop itself: can the new gene spread to other
plants?
There are strict regulations in place for growing
and testing GM plants. They have to be grown
alongside the unmodified version and both have
to be compared to see if their nutrient content
matches and whether there are any toxins in the
GM ones. Two reviews that were published this
year looked at the scientific evidence for the safety
of GM plants. Both show that there is little
evidence for GM crops being harmed by the new
gene and that in the majority of crops the nutrient
contents stays the same. It is less clear whether
GM plants - and the new gene or the protein it
produces - are safe for animals or humans to eat.
Tests done on rats to see if a diet of GMOs have
any harmful effects have shown that most are
safe. The limitation of these tests are that they are
only run for 90 days, which is not long enough
to see the long-term effects.
The environmental concerns about GM crops are
that plants can cross-breed with similar wild
plants and spread genes. There is evidence that
GM plants swap genes with unmodified crops
and wild plants. Like any other type of agriculture,
the effects of genes spreading are not very well
understood.
A criticism of GM studies is that more
independent assessments should be done rather
than studies by the companies who produce and
sell the GM seeds, which is often the case. These
companies are not obligated to make their results
public or to publish them in peer-reviewed
journals. A recent statement by the European
Network of Scientists questions the reliability of
this data based on who is funding it and how
strictly the studies adhere to the regulations for
testing. They urge more stringent testing of the
long-term and environmental effects of GM plants
on both humans and animals.
Companies that develop and sell GM seeds file
patents on these seeds. They justify this by
claiming they need to protect their intellectual
property so as to make it worth their while to
invest in new technologies. The use of patents for
GM plants is controversial because of the potential
for abuse, with companies able to develop
monopolies on seed supply and sue individuals
for violation of their patent agreement. Activists
tout examples of farmers being sued for holding
over patented seeds for a second season and the
use of terminator technology - producing sterile
seeds that can only be used for a single season,
forcing farmers to buy seed every year.
Commercially available seeds do not use
terminator technology, but the possibility is there
for it to be developed. These potential abuses of
GM foods mean that regulation, monitoring and
transparency regarding their use is vital.