First, the basics: genetically modifying something simply means taking a gene from one species, and putting it into another.
The U.S. Agency of Agriculture say 93% of soybeans and 88% of corn is engineered with this technology. That means from cereal, to chips to cookies--or any other products containing corn syrup, canola and soy--the vast majority of processed foods on grocery shelves contain GMOs. But since labeling isn't required in the U.S., there's no way to know for sure.
Seeing for Ourselves
We visited two Vermont farms that couldn't be more different. One uses GMOs, the other is against them.
In Vermont, 96% of dairy farmers use GMOs--like Bill Rowell, who plants GMO corn at his dairy farm in Franklin County.
"We're producing a quality product, with something that science says is quite acceptable," Rowell said.
There's one big reason so many farmers like Rowell have jumped on the GMO bandwagon: efficiency.
"We use the seed that's genetically modified because it produces a greater yield. It's been developed to be drought-resistant, it uses less pesticides, less herbicides, less fuel, less labor," Rowell said.
In other words, it's a sort-of insurance policy against attacks on his crop.
"We have to battle the weather, we have to battle a variety of different insects, pests, rootworm, cutworm, that sort of thing." And he pays a pretty penny for that peace of mind. A bag of GMO seed corn retails at $375, and can plant 2.5 acres of corn. A non-GMO seed bag of the same size costs less, but Rowell says it would yield him less crop.
"You'd reduce your crop by as much as half," he estimated.
Organic farmer Jack Lazor disagrees.
"I think my yields are just as good as anybody who's using GMOs," he said.
Lazor has literally written the book on organic farming. The Organic Grain Grower is a product of decades of experience at Butterworks Farm in Westfield, Vt.
"I grow corn and beans and small grains, wheat, barley, oats, spelt." His dairy farm uses the traditional method of crop rotation, which promotes biodiversity.
"Your soil is teeming with life, and for me, I don't think GMOs are really about promoting life in the soil."
Meet our Scientist
We enlisted the help of Dr. Deborah Neher to sort out the facts about GMOs. She chairs the Plant and Soil Science Department at the University of Vermont, and has published papers on her GMO research.
"GMO is a technology, and as a technology itself it's neutral," she explained. "It's really how one goes about using it that makes a difference."
The biggest negative Neher has found with GMOs has little to do with what we eat. Rather, she says when plants are engineered to be identical and resist certain species, a new pest could wipe out an entire crop.
"That's my biggest concern, is we're really narrowing this genetic base, and making it vulnerable," she said, agreeing with Jack Lazor's philosophy. "So we're not able to adapt to new invasive species."
But Neher says not all GMOs are bad.
"A number of medicines are made with GMO technology, for example the injectable insulin that diabetics use. That's been made through this technology since the 1980s, and I don't think anyone would argue that's a bad use of this technology."
Plus, GMO farmers can use less pesticides and herbicides, and Neher says research shows those chemicals have a greater negative impact on the soil than the GMOs do.
"That convinced me, and I'm a skeptic," Neher said.
When it comes to actually eating products that contain GMOs, Dr. Neher says no studies have proven or disproven the effect of the product on people.
"As far as the human body, I think the jury's still out," she said. "I don't know that we know for sure."
The Food and Drug Administration and the World Health Organization don't know for sure, either. The FDA does not label all GMO products as safe--but says they evaluate the safety of each individual product before it goes on the market. The WHO also says safety should be evaluated on a case-by-case basis.
Science or Sentiment?
Professor Neher remembers the first day of a class she taught called "Plants and Society."
"I started the class with a poll: who's for GMOs, who's against GMOs? The 'against' far outweighed the 'for'. Then we spent the class talking about what it was," Neher explained. "Here's the gene, you're maybe changing a gene, or some genetic component of that. By the end of the class I took the poll again, and it had flipped the opposite." The story outlines what Neher describes as a popular anti-GMO attitude that's not completely based on facts.
"I mean, they've replaced science with sentiment," Bill Rowell said of Vermont's popular anti-GMO faction. "You can't do that."
Still, the majority of European countries have chosen to ban all or some GMOs, and many other restrict the crop.
We asked Rowell if he feared there could be a ban in the U.S.
"If we replace science with sentiment, there could be anything," he said.
"It's an emotional response," Dr. Neher said. "They've been told it's bad, inherently bad, and that's my main point--that it's just a technology. How it's used is bad," she explained.
"I question the quality and integrity of the food I eat," said Rowell. "I don't want to eat something that's not good for you, I don't want my grandson to be compromised by something that's not right."
For Jack Lazor's organic farm, GMOs are still just too unnatural. Plus, he's found a way around using pesticides, which is the main pro-GMO argument. Crop rotation and sod help him with weeds and pests.
"It's sort of like farming has turned into war," Lazor said. "It's us against nature. It should be us with nature."
But Rowell says humans have already disrupted nature just by being on Earth.
"Everybody feels as though what they do doesn't have any impact. But the fact that we're here at all is an impact in itself, isn't it?
Vermont's Labeling Law
Vermont made history on May 8 when Gov. Peter Shumlin (D-Vermont) signed the GMO labeling bill into law.
The bill is the first of its kind in the United States, though 60 other countries already label products that contain foods with genetically engineered ingredients.
While some companies voluntarily label that their foods are "non-GMO," this law requires manufacturers who do use the technology to label it. That includes the majority of processed foods in the U.S. It will also clear up confusion about "all natural" labels.
The legislature passed this law without a trigger clause, which would've required other states to pass a law first in order to share the burden of a lawsuit from GMO manufacturers. Connecticut and Maine have passed labeling laws with trigger clauses. Those states' laws will not be triggered by Vermont.
Below, you can click to see the status of GMO labeling legislation in all 50 states:
Blue = GMO labeling law with no trigger clause
Green = GMO labeling law with trigger clause
Red = Active GMO labeling legislation
Yellow = Ballot initiative
White = No legislation.
Data from the Center for Food Safety.
In Vermont, the next step is probably a lawsuit. Large grocery manufacturers like Monsanto are likely sue the state to protect their investment in GMO technology.
The potential for legal action is why Maine and Connecticut chose to pass their GMO labeling laws with trigger clauses that are unlikely to be triggered.
Vermont has set up the Food Fight Fund, with hopes of collecting at least $1.5 million from supporters all over the country to support Attorney General Bill Sorrell's efforts to win the lawsuit.
Sorrell has begun the rule-making process for the law. He is asking for input from the public and the manufacturers, grocers, producers and consumers that will be affected.
Vermonters will start to see GMO labels on grocery shelves in 2016.
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