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A Voter's Guide To The Science Of GE Foods

Jointed goatgrass grows alongside wheat in fields. As farmers have increasingly used genetically engineered crops, herbicide-resistant weeds have become more common.

Jointed goatgrass grows alongside wheat in fields. As farmers have increasingly used genetically engineered crops, herbicide-resistant weeds have become more common.

Matt Lavin/Wikimedia Commons

Media in Oregon is rife right now with information about genetically engineered foods, much of it conflicting and filled with emotional appeals.

Voters are awash in information because they’ll have to decide in November on Measure 92, which requires the labeling of all GE foods.

In this case, more info isn’t always necessarily better.

“I hate this issue,” said Frank Morton, an organic seed farmer from Philomath, Oregon. “It’s eating my life.”

Morton’s exasperation comes from dealing with years of spin on the issue, and the time he spent serving on Gov. John Kitzhaber’s Task Force on Genetic Engineering.

Oregon voters hoping science can provide a clear perspective on GE foods should brace themselves because there are few easy answers.

The more science you read on this issue, the more you may understand Morton’s point of view.

Are GE Foods Safe To Eat?

Though it’s an often complicated issue, the science on the safety of existing commercial GE crops  — including corn, soybeans, alfalfa, canola, cotton, papaya and rice — is fairly clear.

A 2013 review of the last 10 years of research concluded definitively that “scientific research conducted so far has not detected any significant hazard directly connected with the use of [genetically engineered] crops.”

Many GE crops are also used to feed livestock. And a broad 2014 review of studies covering 100 billion animals eating GE crops “revealed that the performance and health of GE-fed animals are comparable with those fed isogenic non-GE crop lines.”

Basically, after countless meals of GE crops served to people and animals, there just haven’t been a scientifically notable number of health problems.

How Rigorous Are GE Crop Tests?

The divisive debate on genetic engineering science begins before seed ever gets put to soil.  

GE seeds are patented products protected by their creators: companies like Monsanto, Syngenta and Dow Chemical. That means scientists need permission to use the patented seeds in their research.

“In my opinion, there’s not really good science on the benefits and drawbacks of the technology because scientists can’t do that work without permission,” said seed grower Morton.

Opponents of the crops say this conflict of interest casts a cloud over the research that’s been done so far. Even some supporters of GE crops agree it’s not the best circumstances for independent science.

But some scientists say independent study is still possible.

Portland State University biologist Todd Rosenstiel is one such scientist. In recent years, he and his students examined whether certain strains of pesticide-producing GE corn killed soil fungus.

The initial studies didn’t look good for the GE corn. They were published even after Monsanto and Syngenta scientists reviewed the studies. Further trials with the corn eventually showed that it didn’t hurt the soil fungus.

“In principle it worked out fine and we were able to gain access to a large variety of corn strains for our studies,” Rosenstiel said. “I think these companies are trying to be somewhat good citizens. Could they be easier to access? Sure, but they are giving access.”

Similarly, there are questions as to how much control agrochemical companies have over the federal regulatory process that puts GE crops on the commercial market.

All of this isn’t to say there couldn’t be future health issues that arise from GE crops that haven’t been created yet, or that there aren’t any studies questioning the safety of GE crops.

The most often cited study by opponents of biotech crops is a 2012 article published in the journal “Food and Chemical Toxicology.” That study found that rats eating GE corn were more likely to get tumors than similar rats that didn’t eat them.

The study was eventually retracted by the journal because it said its methods weren’t rigorous enough. A review of the study’s raw data concluded that the sample sizes were too small, and the rats used in the study are prone to tumors as they age, so it couldn’t necessarily be attributed to GE crops.

Some GE labeling advocates argue that the rat study shouldn’t have been thrown out. There are even questionable ethics theories spun from its dismissal. But even if the study is accepted as a valid indicator that more testing is warranted, it’s still in the very small minority of research findings that point to problems with GE crops.

“These crops are not some little experiment that a few people have eaten. If they really were bad, it’s something we would have seen by now,” said Steven Strauss, an Oregon State University biologist who also served on Kitzhaber’s task force. “I just continue not to see it.”

But labeling advocates say that GE crops haven’t been around long enough for scientists to know about long-term health effects. They first appeared on a commercial scale in the mid-1990s.

“They’re increasing the toxic load in the food chain for us,” said seed farmer Morton.

That’s an accurate statement, considering that most of the commercially grown GE crops are farmed because they are either herbicide-resistant, produce natural pesticides to kill insects or do both. GE crops have allowed farmers to use more herbicides by volume, and those chemicals can appear in food.

The difference between GE supporters and opponents on this question comes down to whether you trust the existing mountain of studies or worry about long-term health effects that are difficult to quantify.

Grist writer Nathanael Johnson sums up the disconnect between current science and advocacy in his exhaustive “panic-free” reporting on genetic engineering:

“It’s hard to make the case that we should trust science and act to stem global warming, while at the same time we are scoffing at statements of *snort* scientists on genetic modification.”

What About The Environment?

The other major scientific concern cited by opponents of GE crops is the effect they may be having on the environment.

One of the most common traits introduced into GE crops is to make them resistant to the herbicide glyphosate, which is the primary weed-killer in Monsanto’s Roundup product. This has led to more and more farmers relying on so-called “Roundup Ready” crops to make it easier to control weeds.

An empty seed bag that once contained genetically engineered corn seed. Herbicide resistance is one of the most common traits found in GE crops.

An empty seed bag that once contained genetically engineered corn seed. Herbicide resistance is one of the most common traits found in GE crops.

Orin Hargraves / Wikimedia Commons

Fewer weeds means healthier plants and potentially bigger yields — good news for farmers. The bad news is that growers have come to rely on glyphosate so much that weeds are becoming resistant to it.

“There’s definitely been a rise in glyphosate-resistant weeds,” said OSU weed researcher Carol Mallory-Smith. She’s a leader in her field and says herbicide resistance is a serious concern.

As more and more acres of American farmland begin to have herbicide-resistant weeds, controlling those weeds becomes more complex. Farmers may have to spray a wider variety of herbicides to kill weeds or regularly till their land, which can lead to agricultural runoff that is harmful to rivers and streams.

Mallory-Smith criticizes the GE crop industry’s response to herbicide-resistant weeds, which has been to seek approval for new GE traits that would allow plants to survive more toxic herbicides like 2,4-D and dicamba.

“Trying to solve a problem by using the same thing that caused the problem isn’t a very good approach,” she said.

Even though Roundup Ready crops did lead to more herbicides being used when you measure by the amount sprayed, that’s not the only factor to consider on this issue. Insecticide use has gone down because of GE crops.

Scientists also look at the toxicity of the herbicides being used and by all accounts glyphosate is less toxic than the alternatives that were being used before GE crops were introduced.

Mallory-Smith said trying to determine the net toxicity of pesticides used on American crops is important to consider.

“I think that’s a very difficult thing to assess,” she said. “You could read a lot of data and come to the conclusion that the pounds of herbicide went up but the overall toxicity went down.”

But if agrochemical companies do decide to produce new GE crops that are resistant to more toxic herbicides, that equation could change.

A 2012 study by Washington State University found that “heightened risk of public health impacts can be expected” if crops resistant to more types of herbicides come on the market.

Another environmental issue raised by GE opponents is traditional crops becoming contaminated by pollen from GE crops. Scientists call this gene flow, and it does happen.

It’s a particularly problematic issue for specialty seed growers in Oregon, who often sell to markets in Asia that want absolutely no GE traits in their products.

“This is a trade issue, not an ‘I don’t like Monsanto’ issue,” Morton said.

Politics At Play

While there are legitimate environmental questions around the use of GE crops, both sides also tend to distort scientific facts in their favor, particularly in the political season of an election year.

For example, advocates of GE crops say herbicide resistant weeds have been around since before the 1990s, which is true. But it doesn’t accurately convey the increasing number of acres that have Roundup resistant weeds on them today.

And opponents of GE foods have tried to link the crops to a recent U.S. Geological Survey study examining how pesticides may be killing bees in the Midwest. The basic argument is that GE crop seeds are being coated with neonicatinoids, a type of pesticide thought to harm pollinators. But the scientists behind that study say cause and correlation in that argument don’t match up.

“I don’t have a good sense at how linked GE crops and seed coating are,” said USGS research hydrologist Kathy Kuivila, who worked on that study. “My guess is that they correlate, but whether one drives another is tough to say.”

Whether spin by either side influences voters isn’t clear.

A new OPB/Fox12 poll shows that Oregonians are slightly in favor of labeling genetically-engineered foods.

It’s a close split just weeks before the Nov. 4 election, and shows how complex and divisive genetically engineered foods are as a topic. After all, both sides are fighting over what goes on your dinner plate every night.

But one thing is clear: As more money flows into Oregon from across the country to support the ad campaigns around Measure 92, neither side is giving consumers a clear picture of the complicated science around GE crops.

genetically engineered foods USDA GE crops 2014 election

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