|The next generation of GMOs could be especially dangerous
Did a recent scientific study just change the way we should think
about the safety of genetically modified foods? According to Ari Levaux at the Atlantic, the answer is a resounding yes.
The study in
question, performed by researchers at Chinaís Nanjing University and published
in the journal Cell Research,
found that a form of genetic material -- called microRNA -- from conventional
rice survived the human digestive process and proceeded to affect cholesterol
function in humans.
Levaux argues that
this new study "reveals a pathway by which genetically modified (GM) foods
might influence human health" which should cause us to completely revisit the
question of GM cropsí safety. And heís right to be alarmed, just a little off
on the reasoning.
Letís take a closer look at how this study
applies to current GM technology, shall we?
I would argue that several studies have
already suggested that existing GM foods might present a health risk. For
example, this study in The International Journal of Biological Sciences found evidence that
Monsantoís Bt corn causes organ damage in lab animals. Then thereís this one which showed that GM soybeans can alter
mice on the cellular level -- an indication that genetically modified material
survives digestion and is active in animals that consume it.
advocates of genetically modified foods will observe that the phenomenon of
genetic transfer through consumption applies to all plants and
that GM foods are therefore "substantially equivalent" to non-GM foods. As Levaux
explains at length, this concept of substantial equivalence has been
used by the biotech industry as well as our government to push GM foods through
safety testing with minimal scrutiny. Whatís Monsantoís defense of all this? On its website, the company claims:
There is no need to
test the safety of DNA introduced into GM crops. DNA (and resulting RNA) is
present in almost all foods ... DNA is non-toxic and the presence of DNA, in and
of itself, presents no hazard ... So long as the introduced protein is
determined to be safe, food from GM crops determined to be substantially
equivalent is not expected to pose any health risks.
So the fact that the Chinese team found active
genetic material going from plants to humans isnít really new and doesnít
really change what we know about how existing genetically engineered crops
might affect us.
But what is new -- and what Levaux missed --
is that the Chinese study happens to involve exactly the kind of genetic
matrieral -- microRNA -- that biotech companies hope to use in their next
generation of genetically modified foods.
Todayís GMOs are almost entirely based on adding
new genes to crops like corn, soy, and cotton in order to alter the way the
plants function. And even then new functions are mostly limited to making
plants either able to tolerate herbicides or to produce their own. But if
biotechnology companies are successful in their efforts, there may soon be
genetically modified foods that use microRNA -- simply put, snippets of RNA
whose potency were only discovered around a decade ago -- to target, and block
the function of specific genes in pests.
Thus the news that plant microRNA can survive
digestion and affect human systems brings into question the wisdom of pursuing
this kind of technology in food.
As explained to me by Doug Gurian-Sherman, senior scientist for the Union of Concerned Scientists and expert in
genetically modified foods, microRNA technology is an area that biotech
companies are actively pursuing. Monsanto itself has a whole web page devoted to the
technology, which they call RNA
Gurian-Sherman notes that the Chinese study --
though requiring confirmation and follow-up research -- raises "an initial red
flag." It calls into question "any general statement that [microRNA] technology
would be inherently safe," he adds.
He observes that humans and insects share a
surprising amount of DNA material -- evolution favors reusing and recycling
genes even among creatures as different as insects and humans. If this research
bears out, then itís entirely possible that microRNA meant to target a specific
insect gene will also have an effect -- possibly unpredictable -- in humans.
This is especially true because, for technology like this to work as a
pesticide, the microRNA must be present in high levels in the plant, which
makes it even more likely the genetic material will make it all the way into
the human gut.
Gurian-Sherman also pointed out that microRNA
techology poses an even greater environmental risk. There are many beneficial
insects, such as various beetle species, that are closely related to crop pests
and can coexist in the same field. Itís thus hard to imagine being able to
find a gene to target in a pest that wonít also hurt their beneficial cousins
(though this is unlikely to matter to biotech companies).
So where does this new research leave us? It
suggests that, given the possibility of affecting humans and other bystander
species, microRNA-based technology would require unimaginably high safety
standards. And neither the biotech industry nor federal regulators have really
shown an appetite for that kind of rigorous testing. Am I the only one who
doesnít see that changing anytime soon?
UPDATE: Dr. Michael Hansen, Senior Scientist at
Consumers Union wrote to me after this post was published with an
important point about the significance of the Chinese study. While he
agreed that the main implications relate to the possible risk from
microRNA-based GM foods, he also felt that this study did make a new and
somewhat startling finding regarding how plant genetic material affects
humans. As he put it, the study "showed that the miRNA not only
survived digestion [in humans] but also was taken up and moved to other
parts of the body where a specific impact was noted. The studies you
cited -- from Seraliniís lab and Malatestaís lab -- only show that GE
crops can have an adverse effect on animals."
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