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In this issue:
Letter from the EditorDuring the past few workshops, it has come to our attention that many of our stakeholders still have questions about genetically modified (GM) crops and their impact on the environment and society.
We have decided to dedicate this issue to a few general aspects of GM crops and their use in modern society. We have also included a study on the contentious issue of glyphosate.
Please feel free to contact us with any further questions.
Dr John BeckerEditor
The benefits of GMOsAlthough genetically modified organisms have been around for many years, it is still a topic that has seen much discussion, confusion and curiosity. The benefits of GMO crops have been studied extensively. A report on GM crops in developing countries, published by the Nuffield Council on Bioethics, explains the possible benefits of these crops.
Insect and pest resistance
Half the cotton grown in China in 2002 was Bt cotton. Bt cotton has been genetically modified by the insertion of one or more genes from a common soil bacterium, Bacillus thuringiensis. These genes encode for the production of insecticidal proteins. Genetically transformed plants therefore produce one or more toxins as they grow. Farmers had previously applied the toxin directly by spraying the crops. The benefits of Bt cotton are a reduction in pesticide use, an increase in yields and profits, and health benefits for farmworkers who often apply pesticides without protective clothing.
Disease resistance
Plants can be genetically modified to be resistant to bacterial, fungal or viral infestation. Examples of research that has been conducted on genetic modification includes research on sweet potatoes to improve viral resistance and research on bananas that have been modified to resist the black sigatoka fungus. Untreated, this fungus can reduce banana yields by as
• A recap of the benefits of GMOs
• Some more frequently asked questions answered
• What is the deal with glyphosate?
much as 70%. Fungicides are expensive, and using a GM crop can be more economical for farmers.
Crops and the environment
Plants can be genetically modified to withstand harsh conditions, such as drought, to increase the crop yield in areas where it is most needed.
Issue : 13Monthly Newsletter
A gene from a plant that can survive prolonged water stress in desert conditions has been introduced into rice. This allows rice to produce a sugar that protects the plant during dehydration, allowing it to survive periods of drought.
Herbicide tolerance
Plants can be genetically modified to tolerate a specific
weedkiller. This allows farmers to control a wide range of weeds with less weedkiller, while not affecting the modified crop. Herbicide-tolerant crops are grown mainly in developed countries. However, they have recently been used in some developing countries.
Improved nutritional value
Crops can be genetically modified to contain additional nutrients that are lacking from the diets of people in developing countries. One example is golden rice, which has been modified to have enhanced levels of ß-carotene, to help prevent vitamin A deficiency. Some 14 million children under five suffer clinically from this deficiency, which can cause childhood blindness.
Biopharmaceuticals
Plants could be genetically modified to produce vaccines or other medicines. Potatoes have been modified to produce edible vaccines against E. coli bacteria, which cause diarrhoea. This would allow cheap and easy distribution of the vaccine, but research is still at an early stage.
Download the chapter on the benefits of GMOs at: http://nuffieldbioethics.org/wp-content/uploads/2014/07/GM-Crops-2-Chapter-3-Current-and-potential-uses-of-GM-Crops-in-developing-countries.pdf.
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: Newsletter - Issue 13
Frequently asked GMO questions answeredWhy would farmers use GMOs other than the natural way?
How much land do GMOs save?
What are the most common genes that go into GMOs?
Do GMOs contribute to the death of bees and butterflies?
How do GMOs relate to biotechnology? How much nutritional value is lost with GMOs?
GMOs do not contribute
to the death of non-pest
species of butterflies, but
some types of Bt proteins
purposefully kill particular
moth and butterfly species.
These Bt proteins can
be produced by plants
when they are genetically
modified. However, this
targeting is intentionally
aimed at moth or butterfly
pest species that would
be killed with insecticide
sprays if Bt were not used.
Bt proteins are very specific
in this regard. Some non-
pest species of butterflies
can be killed using Bt.
However, the butterflies
need to eat the Bt in order
to die. Only pest species,
not non-pest species, eat
GMO plants. Therefore, the
non-target pest species are
not exposed to the Bt and
do not die.
Crops improved
through the means of
biotechnology save
land in two ways. One is
termed “land sparing”,
which means that if
farmers can produce
more output per planted
acre, there is reduced
pressure to add more
farmed land to keep
up with growing global
demand. The second
way that biotech
crops “save land” is
more literal. Particularly
when farmland is
tilled (plowed) for
weed control, it is very
susceptible to erosion by
water or wind. Topsoil is
an extremely valuable
feature of farmland, and
globally the loss of topsoil
to erosion (water and
wind) is a major problem
for the sustainability of
farming.
There are no common
genes per se that
go into GMOs.
Researchers address
the development of a
novel trait for plants, be
it an input or output trait,
by seeking gene(s) that
can impart the genetic
variation required to
influence the trait under
consideration. The
source or type of gene(s)
has no commonality,
except that it originates
from nature.
Biotechnology is an umbrella term for a set of tools that uses
living organisms (or parts of organisms) to make or modify
a product, improve plants, trees or animals, or develop
microorganisms for specific uses. Examples of biotechnology
include traditional applications, such as the making of bread,
cheese, wine and beer, and more modern applications
to grow or culture cells for research or to make genetically
modified crops for food, feed, fuel and fibre. Biotechnology
can also refer to pharmaceutical applications.
No nutritional value is lost in GM food in comparison to non-GM
food. Simply put, there is no nutritional difference between
GM and non-GM food unless it has specifically been fortified.
An example of a purposefully fortified GM crop is golden rice
to which beta carotene, the precursor of vitamin A, has been
added.
The Bt trait in GM sweetcorn
protects the ear from
earworms while using 75%
less insecticide in spray
applications versus what
would have been used for
non-GM varieties. Using GM
crops reduces farmers’ overall
pesticide application by over
50% and cuts fuel use by over
70%, all while harvesting 15%
to 20% more of the crop due
to the excellent protection
from earworms. Simply put,
they are better for consumers
and better for our land
resources.
GM crops are not any more
or less natural than any other
modern food production
method. Yes, GM crops may
have a gene inserted or
“turned off”, but humans have
been adjusting the genetics
of useful plant varieties for
thousands of years.
Questions and answers were sourced from the GMO Answers website
at https://gmoanswers.com/
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Frequently asked GMO questions answeredCan GM crops help address world hunger?
How can you be sure that GM foods will not affect human health in the long-term?
Is it true that all maize on the planet is already genetically modified?
Do GM foods pose a greater risk of allergic reactions?
Before a GMO can get to
market, it must undergo a
rigorous testing process to
ensure it does not introduce
new allergens. The Food and
Drug Administration (FDA) in
the USA explains: “Evaluating
the safety of food from a
genetically engineered plant
is a comprehensive process
that includes several steps.
Generally, the developer
identifies the distinguishing
attributes of new genetic traits
and assesses whether any
new material that a person
consumed in food made from
the genetically engineered
plants could be toxic or
allergenic.”
GM crops have been
contributing to improving
global food security
for 20 years now.
GM varieties of corn
and soybeans have
been adopted in 13
developing countries
and have increased
crop production. In the
11 developing countries
where GM cotton has
been commercialised,
farmer revenues have
increased, allowing
farmers to purchase
greater amounts of
food, thus reducing
their household’s food
insecurity.
GM foods have
a long, safe track
record (17 years in the
marketplace). Since
their introduction in
1996 until now, scientists
have found, through
repeated and extensive
testing, that GM foods
are no more risky than
comparable non-GM
foods, nor do they differ
in nutritional value.
Does glyphosate cause a flush of bacteria growth in soil that might benefit the next growth of weed seeds?
No, it does not. A flush
of bacterial growth in
soil would only result
from significant inputs
of nutrients to the soil.
The levels of carbon,
phosphorous and
nitrogen added to the soil
from glyphosate breaking
down is very low and will
not result in flushes of
bacterial growth in soil or
a situation where weed
seeds in the seed bank
would benefit.
Maize has been grown by humans for approximately 10 000 years, and its genetics has been heavily modified through breeding and mutation to improve its utility as a crop over this very long period. The modern technique of transgenesis has been used to further improve the agronomic characteristics of maize over the last two decades. Transgenesis has become synonymous with the term “genetically modified” over this period, but it is really a misnomer. So all maize on the planet has been genetically modified by human activities, but not all maize has transgenes inserted by the modern technique of transgenesis.
Have GMO foods led to an increase in the development of allergies among certain groups of people?
The Food and Drug Administration (FDA) in the USA has set forth guidelines
related to the use of GMOs. Those documents reference the science that
indicates that food developed through biotechnology is digested in the
same manner as other foods and therefore provides the same nutrition, or in
some cases more nutrition (if the goal of the biotechnology was to enhance
nutrient content). The science also indicates that these foods are safe for
consumption and do not contribute to increased allergies.
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: Newsletter - Issue 13
Analysing the carcinogenic potential of glyphosateGlyphosate is a commonly used broad-spectrum herbicide that has been around since 1974. It effectively suppresses the growth of many species of trees, grasses and weeds. Glyphosate works by interfering with the synthesis of the aromatic amino acids phenylalanine, tyrosine and tryptophan through the inhibition of the enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS).
The inhibition of the synthesis of these amino acids stops the growth of plants such as weeds. Most importantly, EPSPS is not present in mammals, which obtain their essential aromatic amino acids from their diet.
Several reports state that, while glyphosate is usually linked to the cultivation of genetically modified (GM) crops, people are oblivious to the fact that glyphosate is also used on several non-GMO crops as a ripening or drying agent. When these crops are almost ripe, farmers can spray them with glyphosate herbicides to kill the plant that causes it to dry down for a rapid harvest. In addition to food, glysophate has been found in the air, rain, soil, rivers, streams and groundwater.
In 2015, the International Agency for Research on Cancer (IARC) published a paper concluding that glyphosate is “probably carcinogenic to humans”. This was based on limited evidence in humans and sufficient evidence in experimental animals.
As a result, 15 scientific experts were selected based on their expertise and credibility in the international scientific community. They were recruited by Intertek (a worldwide group of testing laboratories for the
textile, footwear, toy, petroleum and chemical industries) to participate on four independent expert panels for a thorough critique of the evidence related to the IARC’s assessment. They were also to review all relevant information related to glyphosate exposure, animal carcinogenicity, genotoxicity and epidemiological studies. All key studies or publications mentioned by the IARC were made available to the panelists for their review before the meeting. The epidemiology panel conducted its own independent literature search. The scientists had to closely examine the studies or data that the IARC used to come to their conclusions.
Concerning exposure to glyphosate, there is a strong dataset on glyphosate exposure to humans. Even in extreme scenarios, the systemic exposure to applicators, bystanders and the public is quite small. There is an exceptionally large margin of safety from exposure to glyphosate via normal use.
The epidemiology expert panel conducted a systematic review of the published glyphosate literature for the two cancers that were the focus of the IARC’s epidemiology review, namely non-Hodgkin’s
lymphoma (NHL) and multiple myeloma (MM).
The assessment of the epidemiological data found that the data does not support a causal relationship between glyphosate exposure and NHL. The data was judged too sparse to assess a potential relationship between glyphosate exposure and MM.
Two of the panels, namely the animal bioassay and the genetic toxicology panels, presented a critique on the IARC’s position regarding conclusions made in these areas. These panels found that the frequency of neoplasms in the animal bioassays were not to be associated with glyphosate exposure based by the fact that they lacked statistical strength, were inconsistent across studies, lacked dose-response relationships or were not plausible from a mechanistic perspective.
The weight-of-evidence approach – a universally recommended method for evaluating databases associated with glyphosate – was used to determine findings. The most suitable conclusion supported by the data is that there is no strong evidence that glyphosates produce oxidative damage to DNA that leads to a genotoxic hazard or
mechanism for the introduction of cancer in experimental animals or in humans. Generally, extensive reviews of the genotoxicity of glyphosate, aminomethylphosphonic acid (AMPA) and glyphosphate-based formulations (GBFs) that were available prior to the development of the IARC Glyphosate Monograph support the conclusion that glyphosate (and related materials) is inherently not genotoxic.
As a result, following the review of the totality of the evidence, the panels concluded that the data does not support the IARC’s conclusion that glyphosate is a “probable human carcinogen” and, consistent with previous regulatory assessments, further concluded that glyphosate is not likely to pose a carcinogenic risk to humans.
This article was adapted from an article titled: A review of the carcinogenic potential of glyphosate by four independent expert panels and comparison to the IARC assessment in the Critical Reviews in Toxicology Journal. Read the full report at: http://www.tandfonline.com/doi/full/10.1080/10408444.2016.1214677.
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