David
Cameron’s science advisors have urged the government to scrap restrictions on
widespread growing of genetically modified crops in the UK, insisting decades
of experience around the world shows they are safe. Opponents are still adamant
they are not. What is the latest evidence on both sides?
Wheat provides about 20% of the
calories eaten by humans.
I’ve
had to sign off, I’m afraid. There is much, much more to look at. As part of
the redesigned Reality Check homepage we will be trying to corral blogs on
similar subjects into the same place, so I look forward to re-opening this
debate soon.
I
can’t post and reply to all the links you have sent below the line and by
Twitter before I close, but I will go through them as soon as I can and either
update the blog or add a list of some of those I think worth following below
the line.
Thanks
for such a great response today. I don’t have a firm view before or against GM
- despite what some of you seem to think! - so I really appreciated the very
high number of people sending good information, pertinent challenges and links
to source material.
Summary
It’s
fair to say today’s stated aim was too ambitious for the time available. I’ve
only managed to really address the growing of GM crops (not the eating of them
as the title suggested), and only really analysed the latest key report arguing
they are safe. A start, but much more work can be done.
I
have also not had time to address the risk of crop contamination, say to
organic farmers. And as GM technology develops, the debate will evolve too. For
example the latest UK report looks forward to more non-plant genes being used
in crops:
The
next generation of GM crops is expected to be improved not only by transfer of
genetic elements between crop species but also from diverse organisms into
crops.
The
exercise has some tentative conclusions though:
- There is agreement that since most GM crops are adapted to be tolerant to herbicides and pesticides, many more chemicals are sprayed, leading to resistant weeds and insects, and loss of biodiversity; pro- and anti-GM arguments differ on whether banning GM or changing farming practices is the answer.
- No serious risk to human health has been proven, though given the some of the more sweeping statements of safety seem to be misplaced; however even supporters acknowledge some of the processes that cause concern, but they argue this applies equally to non GM food.
- Wiser supporters of GM are not saying it is and will always be risk-free - their argument is a more nuanced suggestion that the principle of GM is not inherently risky and/or GM crops are no more risky than traditional varieties, and so GM plants should be regulated in the same way.
The US experience continued...
One
of the links I have been sent by opponents of GM is to an interview with Tom
Dempsey, head of the US Snack Foods Association. In his conversation with the website bakeryandsnacks.com,
Dempsey talks about why “in their masses” manufacturers were removing GM
ingredients from their products:
Clearly
in a litigious society that we have right now, whether you are right or wrong,
that litigation costs hundreds of thousands if not millions of dollars. So if
you can do it, if you can in effect make your end product GMO-free at an
attractive price, then it’s a benefit to do it.
Note,
Dempsey is not saying there is any basis to the litigation, but clearly
manufacturers are not confident enough to ignore it. It is curious they were
happy to include GM ingredients early on, but are not now there is a longer
history of evidence.
In
light of this, a line from the UK report today strikes me as potentially
significant. It says, almost in passing:
The
last crop to benefit from GM technology has been sugarbeet, with a herbicide
resistant variety introduced in the USA in 2012, and now accounting for around
95% of the crop grown.
From
zero to almost everything in two years or less seems like a very short time
span to judge the long term impact of this crop.
Continuing
the summary and responses of the evidence in today’s report that there is no
reliable evidence of harm from GM crops, part two is environmental damage. For
clarity the report claims are in bold, my summary of responses in italics.
The
report admits there is “no question” that widespread growing of herbicide
tolerant crops has led to wider spraying of herbicide chemicals, resulting in
the development of resistant super-weeds, and the “likely” reduction in wider
biodiversity. It also accepts there could have been examples of damage to
non-target insects, and has been cross-pollination with non-GM plants.
However
the authors suggest this is not the fault of the GM crops per se (their
italics), but farm management (such as the intensive use of certain chemicals),
and could also have happened with conventionally bred plants. It suggests the
answer is better farm management.
Opponents
of GM might point out that the very point of developing herbicide tolerant
plants was so farmers could spray more chemicals. It is the case though that
farming has a history of having to adapt to short-term mistakes, and could
learn to manage this better.
They
also claim there are “a number of environmental benefits” including reduced
greenhouse gas emissions, reduced soil tillage (used to tackle weeds) and the
nutrient loss this causes, and the use of “more benign” herbicides.
To
support this claim they cite the following paper: “ Brookes, G. & Barfoot,
P., 2013b, Key environmental impacts of global genetically modified (GM) crop
use 1996-2011. GM Crops and Food: Biotechnology in Agriculture and the Food
Chain, 4(2), pp.109–119.” It turns out this is a report by the two owners of a
consultancy, PG Economics, who specialise in advising the industry about plant
biotechnology, among other things. This is not to suggest their work is not
rigorous and honest, only to point out that as a single source for a sweeping
claim of environmental benefits it might be considered weak.
Today’s
report is unambiguous:
There
are no reliable data indicating inherent risk for human or animal health, for
the environment or from unforseen effects.
Later
it goes into more detail on those three points.
Here
is my summary of what they say about human and animal health, and
reaction or comment in italics after each point raised. I will take on the
other two areas in later posts.
A
few studies led by an Italian scientist Gilles-Eric Séralini have reported health
risks from GM food and animal feed, notably one in 2012 linking a
herbicide-tolerant maize to tumours and early death in rats. The report says
“in each case, the scientific community and food safety authorities found that
the evidence did not support the conclusions”, and notes that the 2012 paper
was later withdrawn by the journal.
John
Vidal has pointed me to scientists who are alarmed at the way Séralini and
others have been vilified. You can see their response here.
The
report notes some criticsims are based on “hypotheses that harm could occur
under certain scenarios”, notably the risk that plant genes could effect
genes in animal organs. The authors say this has already been “described”
for non GM plants.
They
do not, however, address the suggested bio-security hazard directly. This is
perhaps because the focus of the report is on changing regulation to make it
easier to plant GM crops but still acknowledging some will not pass regulatory
safety tests.
A
review of 24 studies of health impacts of GM food found “no statistically
significant differences between GM and non-GM crops within the parameters
observed” (my italics), however other studies have been “inconclusive”.
On
this point the evidence looks more mixed, something which does not feel well
reflected in the more bullish summary statement at the top of this post.
In
the US “there have been no successful lawsuits, no product recalls, no
substantiated ill effects, and no other evidence of risk from a GM crop product
intended for human consumption.”
While
there have been no major public health scandals in the US , I am following at
least one lead which could call this into question - or might not, it is too
soon to say.
I
have asked the Guardian’s environment editor John Vidal to address the argument
that GM crops have been planted in many countries over two decades and there
are no proven problems. This is a very important strand of today’s report to David Cameron.
The
Guardian employs notable journalists who support, or do not have a particular
antipathy to GM crops or food. However as the case for GM has been put
so powerfully by the report which prompted today’s debate I particularly asked
John to counterbalance this with a summary of the arguments on the other side.
These can be followed up in detail where necessary.
John
writes:
Hundreds
of millions of people and animals regularly eat GM foods seemingly without
problem and the industry has argued that this effective giant feeding trial
means the food and crops must be safe. But there are legitimate, nagging doubts
because there is still no requirement in any country for companies to
conduct long term trials.
Distrust
of GM foods has built worldwide because little public research into their
safety is published and what there is has been largely financed by the GM
companies themselves. Moreover, there is no requirement to test the food
by feeding it to successive generations of mice or rats to see whether it
has any identifiable impact. Critics say that the whole regulatory regime for
GM crops is based on information provided by the industry.
While
most researchers agree there is no safety issue, whenever any serious issue is
raised, the industry and its lobbyists have rushed to attack both the research
and smear the scientist. According to some scientists, there is now a a de
facto ban on asking certain questions about the safety of the foods with few
scientists daring to publish critical studies. However, last year a group of 93
scientists declared that there was no scientific consensus on the safety of
genetically modified foods and crops. (This number has now risen
to 297.)
UK
plans to grow herbicide-tolerant GM crops commercially were abandoned in 2004
following the farm scale evaluations, which showed that blanket spraying with
weedkillers destroyed important habitats for birds, butterflies and other
wildlife. Ten years on, more complex mixtures of herbicides are being used to
control pests but little research has been published showing how the
cocktails of chemicals may inter-act.
GM around the world
Quotes
from today’s report published by the Council for Science and Technology:
- The acreage under GM cultivation is doubling every five years and now accounts for some 12% of global arable land.
- In 2012, biotech crops represented 35% of the global commercial seed market.
- In the USA, between 500 – 1,000 field trial applications are approved per annum and 96 applications for commercialisation have been approved since 1990. Several North and South America countries have followed the USA.
- In contrast, in Europe there is only one GM crop approved for commercial cultivation, a Bt-insect-resistant maize. The total area of GM maize grown in the EU in 2012 was 129,000 hectares, of which more than 90% was grown in Spain.
- Although less than 0.1% of the global acreage of GM crops is cultivated in the EU, more than 70% of EU animal protein feed requirements are imported as GM crop products.
- There are few commercial releases of GM crops in Africa (principally in South Africa) (IFPRI (International Food Policy Research Institute) 2013).
- In Asia, there are several countries, including China, that have adopted GM crops with varying degrees of enthusiasm.
Almost
everybody I have talked to today has said words to the effect of: of course it
isn’t about the science, it’s about the politics. This blog is trying to focus
on the science, for want of a better description, but helpfully the Guardian
hosts Jack Stilgoe’s political science blog, which has a post on this today:
The US experience
Another
key thrust of the pro-argument is that, to put it rather crudely, lots and lots
of this stuff is grown in the US, and no harm has been proved.
Clearly
this statement deserves a lot of scrutiny, and much of it will hinge on what is
deemed harm, and to what extent it can or might still be proved. But it is
probably an argument which will have more public resonance than many, and the
figures involved are compelling - if only for the sheer scale of GM over the
other side of the Atlantic.
The
US Department of Agriculture helpfully published its latest report on GM just
last month. Note this refers to Genetically Engineered - or GE - plants and
crops.
For
the sheer scale of GM in the US, take this:
Three
crops (corn, cotton, and soybeans) make up the bulk of the acres planted to GE
crops. U.S. farmers planted about 169 million acres of these GE crops in 2013,
or about half of total land used to grow crops.
To
put this in context the entire land area of the UK is approximately 60m acres.
Source: USDA.
As
for how safe this makes GM, Baulcombe says:
The
European roadblock on GM would be appropriate if there were evidence for an
intrinsic hazard, but there is not. In the highly litigious USA, there has been
no example for more than 20 years of any harm or legal damages being awarded
due to GM crops.
The
statement that there “is not” any evidence of an intrinsic hazard will be one
of the questions I will focus on today.
The science
I
try not to overuse headlines, but to help navigate the different arguments that
are bound to come up in an illogical order, I will do today.
Professor
Sir David Baulcombe in his Guardian comment piece today makes a significant
claim about the safety of GM crops compared to standard plant breeding
techniques. His argument is that GM varieties are less risky because
very few new genes are transferred and they are carefully selected:
Even
the possibility of “unknown unknowns” does not stand up as a legitimate concern
because the unpredictability of a new GM variety is much less than in
conventional breeding. In GM a few new genes are transferred but, in a
conventional hybrid, there are 30,000 genes from each parent and we have no way
of predicting how they will interact. There is no suggestion that conventional
breeding should be subject to a complex and politicised regulatory process but,
correspondingly, there is no reason why GM should have this burden.
I
do not have the scientific knowledge to challenge or confirm this, although an
early question that arises is to what extent non plant genes are being
transferred into crop seeds, which does not happen with conventional hybrids.
I’d be interested if any readers do have more specialist knowledge of this
area, and will of course seek out other experts as soon as possible.
