A
blog of Bridge
Environment, updated most Thursdays
This
entry is the first in a three-part series about genetically modified organisms
(GMOs)
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| GMOs: Monsters or unsung superheroes? |
Genetically modified (GM) food items prompt one of two
reactions. Some people panic, not wanting anything to do with them. The panic reaction
has dominated European politics and led to a near-ban on growing (but not
importing) GMOs. Other people ignore the issue, preferring to remain untroubled
by yet another risk of modern life. The denial reaction has dominated US
politics so far, where even efforts to label GMOs have fallen flat. These two
reactions should not be surprising: they
are our natural human responses to uncertainty. To foster a more
rational debate regarding GM foods, we present a three-part series. Today we
define the term GM, put GM practices into historical context, and consider
human health effects. Next week, we will discuss potential ecological
consequences. In two weeks, we will wrap up the series with a discussion of
intellectual property, market power, and politics. In general, we will conclude
that GMOs pose greater risks than proponents would have you believe, but
smaller ones than critics suggest. Rather than ban them outright, we encourage
smart regulation along with accurate education. With proper oversight and regulation,
GMOs are neither terrible monsters nor superheroes capable of saving us from ourselves.
To
start, let’s define GMOs by putting them into historical context. Humans have shaped
our food supply throughout history and have, through farming practices, caused purposeful
genetic modifications in nearly everything we eat. In large part, these modifications
are a result of selective breeding1, whereby people produce the next
generation of domesticated plants or animals using prize specimens. Over
millennia, selective breeding practices shaped the genes of domesticated
grains, vegetables, fruits, meats, and even microbial products like cheese and
wine, making them more productive and more desirable to consume. In this way,
nearly everything we eat could be considered genetically-modified. However, the
GMO term is reserved for a specific method of creating new varieties.
The
next big technology for shaping our food supply came in the first half of the 20th
century when agricultural scientists began causing mutations in plants by
exposing them to radiation or harsh chemicals. The resulting individuals are
screened for desirable traits and, in some cases, interbred with existing strains
to further improve them. The varieties resulting from these processes are even
more genetically-modified than those developed via selective breeding alone,
but still do not qualify for the term GMOs.
Instead
of relying on mutagenic conditions, true GMOs are developed in a calculated and
precise way. Specific properties are sought, appropriate genes are identified
in other organisms, and then a GMO is engineered by combining the genes of
multiple plants or animals, a process referred to as transgenesis. This process
is inspired by transduction. Discovered in the early 1950s, transduction is a natural
phenomenon by which certain viruses are capable of incorporating a piece of DNA
from one host into their own genome, carrying it to another host, and inserting
it into the new host’s DNA. As creepy as this phenomenon sounds, it can be beneficial.
Transduction is involved in the rapid evolution of antibiotic resistance in
bacteria, for example (good for the bacteria even if it is not for us), and has
promise for inserting functional gene copies into cells of people who suffer
from genetic disorders. When creating a GMO, scientists transfer DNA using
plasmids, which have many similarities with the transduction-capable genetic
material of viruses. The scientists’ goal is to create a transgenic
superorganism.
In
some ways, the creation of GMOs is merely a more controlled version of techniques
we have used for millennia. From a policy perspective, what separates this
technique is the rapidity and scope of changes that can be made. The rate of
change offers both promise and peril. For example, consider AquaAdvantage salmon,
also known as the Frankenfish. This GM salmon has been engineered by adding
genes from Chinook salmon (Oncorhynchus
tshawytscha) and ocean pout (Zoarces
americanus) to Atlantic salmon (Salmo
salar). The introduced genes allow the engineered salmon to grow twice as
fast as existing varieties of farmed Atlantic salmon.
The
transgenic nature of GMOs tends to fuel our imagination and make us believe we
are eating something contaminated. In reality, GMOs are made with precise and
controlled technologies compared to the older radiation- and chemical-based
methods. Regardless, the genetic changes are the one major lasting effect of
the environment that created new varieties using either of these techniques. If
there are health risks, they are most likely going to be from the resulting
properties of the food, not the details of its creation.
When
it comes to health consequences, GM foods are not particularly different from other
varieties humans have developed throughout our history. It is possible that any
new variant may have unintentional health effects. The obvious solution to this
challenge is testing, which does take place on GMOs prior to human consumption.
Testing is capable of identifying major toxic issues quickly, but not as
capable of identifying rarer problems like an unusual allergy, or long-term risk
for diseases like cancer, which may only manifest in some individuals and only after
years of exposure.
GMOs
have been in our food supply since the mid-1990s and no human health issues
have yet been identified. This result does not mean that GMOs are all safe for
human consumption. The fact that they can differ so quickly and dramatically
from previous varieties means that GMOs should be subject to additional
scrutiny and longer-term testing than, for example, a variety derived from
selective breeding. However, we should not see GMOs as somehow wholly distinct.
In all cases where a new variety is notably novel, we should consider more
extensive and longer-term testing.
The
same logic applies to labeling. While labeling seems reasonable from a
perspective of informed consumers, producers are legitimately worried that a
GMO label would be seen by the public as a hazard warning. Such a warning may
be warranted if the public does not have faith in the ability of food
regulators to accurately gauge the health risks associated with novel food
items. However, such a concern could be applied equally well to food items
derived via radiation- or chemical-exposure. If we do label, we should do so
based on the novelty of a food and accompany that effort with a public
education campaign.
This
does not necessarily mean that GMOs are safe, but it does mean that health concerns
are less of a factor in regulating GMOs than environmental risks and the
influences of monopoly power. They will be the subject of our blog entries in
the following two weeks.
Best,
Josh
For
more information, read our other blog posts and visit us at Bridge Environment.
1
Selective breeding is so pervasive and effective that it helped inspire Darwin’s
development of evolutionary theory.
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