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Scientists Debate New Study on GMO-Fed Pigs

Study highlights issue of GM seed research restrictions

Science commentators involved in the genetically modified food debate have weighed in on a new study that says pigs fed genetically modified grains suffered a higher rate of severe stomach inflammation and developed heavier uteri.

Some experts have said the study shows evidence of a problem that warrants further study, while others have dismissed it as alarmist “junk science.” While stoking old flames, the study also highlights difficulties researchers face when patent-holders deny access to genetically modified (GM) seeds for studying.

The study, conducted by Australian and U.S. researchers and published Tuesday in the Journal of Organic Systems, followed 168 pigs from weaning age to slaughter weight over the course of nearly 23 weeks. Half of those pigs (84) ate a diet based on GM corn and soy, while the other half ate as close as possible to the same diet based on conventionally grown, non-GM corn and soy.

The researchers found few statistically significant differences between the two groups after comparing them based on nearly 20 different parameters, including weight gain, stomach ulcers and kidney abnormalities. The GM-fed pigs did, however, show significantly higher rates of “severe” stomach inflammation, as well as an average of 25 percent heavier uteri in relation to body weight.

Stomach inflammation was graded on a scale between nil, mild, moderate and severe during blind autopsies, meaning the reporters did not know if they were examining the stomach of a GM or non-GM pig. A table of four photographs embedded in the study’s paper shows an example of each of the four degrees of inflammation, which ranged from a fleshy grey (nil) to a combination of pink and bile-yellow (severe).

Here’s the number the study’s authors highlight as most concerning: 23 GM pigs had severely inflamed stomachs, while only 9 non-GM did. That much of a difference is a red flag deserving of further study, said Michael Hansen, Ph.D., senior scientist for Consumers Union.

Critics were not as certain. Notable climate change author and GMO critic-turned-supporter Mark Lynas pointed out that 60 of non-GM pigs had mild or moderate inflammation compared with 41 GM pigs, and only 4 non-GM pig stomachs were graded “nil,” while the GM pigs tallied up 8.

Of course, fewer GM pigs can have mild or moderate stomach inflammation if a larger percentage already rate as severe, Hansen said to Food Safety News.

Study highlights GMO research hurdle

Another point of contention lies in the potential variance in nutritional composition between the GM and non-GM grain fed to the pigs in the study. Because of patent-holder restrictions, the researchers were required to buy each type of feed from retail distributors, as opposed to growing the feed in a controlled environment.

According to the study’s authors, the GM corn and soy used in the study were considered compositionally and substantially equivalent to the non-GM varieties by government agencies. But the lack of a controlled feed-growing environment potentially calls the results into question, according to Kent Bradford, Ph.D., director of the Seed Biotechnology Center at the University of California, Davis.

“These are different products,” Bradford told Food Safety News. “For example, soy beans can have a wide range of phytoestrogens. The amount varies widely by production.”

But the study’s researchers had little choice but to work with retail GM grains due to one nearly insurmountable research hurdle: grower’s contracts.

Anyone who buys GM seeds is required to sign a technology stewardship agreement that says, in part, that they cannot perform research on the seed. Without express permission from the biotech patent-holder, scientists and farmers risk facing lawsuits for conducting any studies.

“Any study you want to do with these engineered crops, you need to get the company’s permission,” Hansen said. “Could you imagine if tobacco research was only done when the tobacco companies had the final say?”

In July 2009, a group of 26 public sector scientists wrote to the U.S. Environmental Protection Agency to complain about the restrictions imposed on them by the patent holders of GM seeds. In part, they said critical questions regarding GM foods could not be answered without more research freedom, which has still not been established.

“A fishing trip”

On his Science Denialism blog, Mark Hoofnagle, Ph.D., referred to the study as a “fishing trip,” as it did not set out to answer a hypothesis but instead measured a range of parameters in hope that any differences between the groups would appear. The study should have been treated as preliminary research before engaging in hypothesis-driven testing, he said.

“So far, one can only conclude that it’s just as likely that this result occurred by chance as it is to be an actual effect of feeding the pigs GM corn and soy,” Hoofnagle wrote.

But such feeding studies are published “all the time,” Hansen said.

“When you look at a bunch of things and a lot turns out not to be statistically significant but some are, you look at those further,” he added. “You try to explain the significance.”

Hoofnagle also contested the clinical — if not the statistical — significance of the 25 percent increase of GM-fed pig uterus weights over non-GM. The non-GM group had a mean uterus weight of 0.10 percent of total body weight, while the GM group had 0.12 percent. Those percentages ranged from between 0.04 to 0.31 for the non-GM to between 0.036 and 0.244 for the GM.

Growing conditions questioned

Institutions and scientists who came out in support of the study praised its relatively large sample size of 164 pigs, as well as its duration and farming conditions intended to match those seen in commercial pig-farming operations.

Lynas, however, said the study’s data raised questions concerning the low quality of care the pigs endured. Roughly 60 percent of both pig groups had stomach erosions at slaughter, and nearly 60 percent from each group suffered pneumonia, which Lynas called “a classic indicator of bad husbandry.”

The animals were indeed raised in a commercial environment and the data were similar to what is expected in such a setting, said Howard Vlieger, co-author of the study and owner of Verity Farms in Maurice, Iowa, where the study was conducted.

Once they left the nursery, the pigs were raised in “Cargill-style finishing units,” which include both a straw-bedded enclosure and a fenced outdoor area where the pigs eat and drink.

Vlieger told Food Safety News that while the study could not include any anecdotal behavioral observations of the pigs, the researchers did notice a marked difference in temperament between the two groups. When recording the pigs’ weights each week, researchers say that the non-GM pigs were easy-going and generally cooperative, while the GM pigs were noticeably more irritable.

“For whatever reason, as soon as you brought them into confined quarters, they were fighting and biting each other,” Vlieger said. “Every time we did a weighing, the same scenario presented itself.”

GM contracts still pose research problems

Vlieger also lamented the challenges presented by GM patents. The research team chose not to even attempt obtaining GM seeds because of the long-established refusal by biotech companies.

Hansen reiterated that the study’s findings merited further research into the influence GM grains may have on stomach inflammation and uterine weight. But for that to happen, he said, restrictions on how GM seeds can be studied need to be loosened.

“That’s the way good science works,” Hansen said. “If the studies show the engineered crops are fine, fine. But let the scientists study them the way they want.”

For Bradford, the main concern with the study stems from those input limitations. Until GM and non-GM grains can be grown under the same conditions and then administered in a feed test, the results come into automatic question.

“It looks like they did a reasonably careful study,” Bradford said. “It’s just that if you don’t control the food going in, it’s hard to substantiate what comes out. It will be interesting to see what other studies come after this, but right now it’s hard to get too excited.”

© Food Safety News
  • Jesus

    Great information!!

  • JoAnn Alumbaugh

    This is the most balanced report/article I’ve read on this issue. Congratulations to Mr. Andrews for writing an unbiased, objective piece.

  • Radfox

    The study was completed 5 years ago and has been in peer review until now.

  • Robles

    In S.Africa you have to lavel food that contains morethan 5% GMO

    They went nuts when discover that they been fed their babies
    whit 2 products made with 70% GMO and it was not label. What are you feeding
    your Babies with? NO LAVEL !!!

    Monsanto also defined that the test in pigs should it be in weight
    and grow, but is it exactly what the franken fish does?

    How about test in Organs so we do not giving all our money to Drugs Co. and Doctor.

  • Dave Wood

    The Americas North and South export about $60 billion a year of GM crops to Asia, mainly to use as feed for pigs and other domestic livestock. It is impossible that no-one would notice damage to 100 million pigs fed on GM crops each year and then slaughtered for food..

    • mscognizance
    • Jay

      He’s right, in factory farms they don’t care about the animals health (which is very poor), they will give it to is either why. I found a Article where non factory farmers said they can’t feed their animals GMOs, cause then they die, and it’s as simply as that they said. And it dosen’t surprise me there is so many things attacking this study, pretty much anything that tests The health of GMOs, and actually gets out, gets a lot of hate. This study and the rat cancer study are a great example of that, I’ve found several things from sources saying that it’s fake, an dI wouldn’t hold what Mark says very high, I would rather listen to a actual scientist in GMOs, not a random website (Forbes) or a possibly paid off global warming expert (Mark Lynas).

  • Jim Bradford

    This is a fairly balanced review. The review is not the problem. One key problem with the study is the design or number of repetitions for each treatment was very low (2) as the pen was the experimental unit. Also, “Cargill type” units are not commercial state of the art. Pneumonia leads to pigs not eating well and pigs that do not eat well develop erosions. I agree that this study indicates poor pig care and poor scientific approach.

  • http://FarTooMuch.Info JRuss

    Http://NoGMO.FarTooMuch.Info. The lack of essential metal nutrients is characteristic of RoundUp Ready crops. The presence of stomach and gut problems is characteristic of Bt-crops.

  • mscognizance

    Pigs are extremely close to human bodies.

  • N. Kennedy

    “Scientists Debate New Study on GMO-Fed Pigs”, which suggests that the article is bases on the science, yet the article quotes Mark Lynas – a non scientisit. Why? It’s curious thta no-one has pointed that out. Mark Lynas has been challenged on his industry-soundbites-posing-as-science before by gm-cautious scientists, yet refuses to answer.

  • Lori Horbas

    It seems any study that raises doubt in the public’s mind ensures apathy. It is a marketing tactic. The fact that GMOs are only researched by the companies that create, and profit from them, should be cause enough for alarm. That they are not only directly tucked into our food supply unlabeled, but comprise 95% of all animal feed, animals that we eat, is unconscionable. Could there be a master plan? In a country where our Gross National Profit numbers come from health care, not industrial productivity, one wonders what incentive there is to keep its nation’s citizens healthy. Make no mistake Monsanto is the Lex Luther of the agrarian ideal, but Novartis and other companies that research and develop GMOs on one end, and supply pharmaceuticals on the other, are profiting on both ends of the equation. It does not seem a stretch given the small tidbits of research coming out, this study on pigs and another recent study on mice and GMO related tumors, that GMOs could be the root of disease. Precaution, Precaution, Precaution should have been the mantra of a supposedly free country. Now released into nature, GMOs are likely to pollute all of nature to some degree. A degree which likely will increase over time.

    One question: Were the, “conventionally grown Non-GMO corn or soy” fed pigs fed on organic feed? Certified organic grain is the only way I know of to ensure grain is GMO free.

    As an aside: Why is Mark Lynas who is NOT A SCIENTIST, quoted? His comments, similar to my
    own, are an opinion.

    • Renato F De Araujo

      great comment !

    • Jay

      Mark Lynas use to be a anti GMO active, but he is now a expert on global warming and is now pro GMO, why he switched opinions (is you don’t know he started a lot of anti GMO things, there’s a video of him with many other anti GMO protesters in the UK in the early 1990s ripping GMO plants owned by Monsanto out if the ground.) is mystery to me, but in 2011 some documents leaked that could show he was having interactions with Monsanto, those documents lead people to think he was a lobbyist for Monsanto and that he was paid off. Considering he is a expert in global warming, not GMOs, I wouldn’t hold what he says why high.

  • David Moon

    I think the most shocking part about this entire article is that “Anyone who buys GM seeds is required to sign a technology stewardship agreement that says, in part, that they cannot perform research on the seed.” This is absolutely unacceptable, and there is no way it should be legal for ANY company to make that kind of requirement. If you want to perform a science experiment on the safety of anything, you have every right to do so as long as it doesn’t danger anyone else.

    I think that scientists should just agree to fuck the legal agreement, and face the courts. There is no way that could stand in any truly just justice system. Imagine if a pharmaceutical company said that no one could perform research on their products. It’s insanity.

    • Raven

      But yet,no “system” in the United States has anything to do with fair justice or whether something is “jsut”. Courts only ruleon the basis of existing statues, and whether something is “just” or safe is irrelevant (except in cases where the already-existing statues mention safety… in which case safety is only considered to the extreme minimum lined out in the statute, and *actual* safety or health concerns are ignored).

  • Jay

    It pretty much is, infact companies can even have people do studies, then not let them show it to the public unless it has the results they want, same for the FDA. It’s a broken system that needs a over hull big time.