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Rising Public Doubt About The Safety Of Genetically Modified Food

Even with no evidence of health risk, calls for labeling, better study increase

by Britt E. Erickson
April 6, 2015 | A version of this story appeared in Volume 93, Issue 14

Label It
Genetically modified food protesters hold protest signs at a rally in downtown Asheville, N.C.
Credit: Shutterstock
A growing number of people in the U.S. are concerned about the safety of biotech food.

U.S. consumer confidence in the safety of foods that contain genetically modified organisms (GMOs) is falling, according to recent surveys by independent groups. As a result, a growing number of consumer and public health groups are calling for labels on GMO foods, claiming people have the right to know what they are eating. In the absence of federal action, several states are considering laws that would require labeling of GMO foods. Yet there is no evidence of increased harm or risk to human health from eating these products.

The food industry in general is opposed to mandatory GMO food labeling. Manufacturers and their trade groups argue that it would increase food production costs. Large food and chemical corporations have spent tens of millions of dollars annually over the past few years to stop states from adopting mandatory GMO food labeling initiatives.

It is unclear what is driving the growing movement and the push to label bioengineered foods, but some experts speculate that it is triggered by people’s fear stemming from a lack of understanding about this technology. How fast this movement is expanding is hard to tell. Various surveys have tried to quantify the percentage of people in the U.S. who avidly avoid GMOs in food, but their results vary widely.

For example, a survey released earlier this year by the International Food Information Council, an industry-supported group, found that only about 2% of the U.S. population shunned GMOs in food last year. The council acknowledged that public worries about GMOs are on the rise, but it emphasized that the majority of people surveyed last year, or about 93%, thought GMOs in food are safe.

Although the food industry is touting those numbers, they contrast sharply with data reported earlier this year by the Pew Research Center, a nonpartisan group that says it does not take policy positions. The Pew survey, also conducted in 2014, showed that 57% of the general public viewed GMO food as unsafe. Pew also reported that only 11% of scientists believed GMO food is unsafe.

One possible reason for the gap between scientists and the general public, Pew said, is that “two-thirds of the public (67%) say scientists do not have a clear understanding about the health effects” of GMO crops.

That perception may have arisen because companies are not required to submit traditional toxicity data to the Food & Drug Administration before they market GMO foods. Instead, they must show that a GMO food is not substantially different in terms of nutrient and allergen content from its conventional, non-GMO counterpart.

“This comparative approach is used because traditional toxicology studies in animals are not readily applicable to whole foods,” such as apples or corn, said Jason Dietz, a policy analyst in FDA’s Office of Food Additive Safety.

Dietz and representatives from other regulatory agencies, including the Environmental Protection Agency and the European Food Safety Authority, described the processes their agencies use to evaluate the safety of GMO foods during a meeting held last month by a National Research Council (NRC) committee. Experts at the meeting also discussed ways to assess the potential risks of eating GMO foods with respect to allergies and effects on the gastrointestinal tract.

The U.S. approach to evaluating the safety of GMOs in food differs from that adopted last year by the European Union. In the U.S., foods containing GMOs are designated as “generally recognized as safe” and do not require premarket approval by FDA. Companies are encouraged to consult with the agency before they market their products, but they are not required to do so.

FDA reserves the authority, however, to require premarket approval of a food if genetic modification results in the expression of proteins that are significantly different in structure, function, or quality from proteins produced in the conventional version and that are potentially harmful to human health.

Companies wanting to market a new GMO food typically provide FDA with a package of information with molecular characterization data for the inserted DNA and any products expressed from that DNA. The package also includes acute toxicity test data on any new proteins formed, an assessment of allergenicity, and complex compositional analyses, Dietz said. FDA’s approach is consistent with guidelines from Codex Alimentarius, which is the United Nations’ “gold standard” for international food benchmarks, Dietz pointed out.

In contrast to the U.S. system, companies in the EU are required to submit data from 90-day toxicity studies on rodents fed whole food before they market new GMO food products.

Many experts agree, however, that GMO safety assessments that focus on the alterations of a food’s chemical composition resulting from gene modification are more informative than 90-day toxicity studies. “Assessments should be based on the presence of novel compounds or substantial changes in levels of naturally occurring substances like nutrients,” Lynn R. Goldman, dean of the George Washington University School of Public Health, told the NRC committee during a webinar in February. In addition to nutrients, amino acids, vitamins, fatty acids, fiber, mycotoxins, hormones, alkaloids, RNA, and DNA can also be quantified in bioengineered food products. Those levels can then be compared with levels found in the non-GMO version of the product, she said.

Another common way to characterize new GMO foods is to use a massive chemical profiling approach, such as chromatographic or spectroscopic analyses of small organic molecules in complex mixtures. Peaks that occur in spectra for genetically engineered foods but don’t appear in the spectra of the non-GMO counterpart, and vice versa, can be isolated and identified.

“The changes would need to be assessed on a case-by-case basis,” Goldman said. “This is not a one-size-fits-all situation,” she added.

Determining whether a new product poses a risk of allergenicity is also challenging. “At present, there is no definitive test that can be relied upon to predict an allergic response in humans to new proteins in the food supply,” Dietz said. In its current approach, FDA considers “whether the source of the new protein is allergenic and the digestibility of the protein in simulated gastric fluid,” he said. The amino acid sequences of new proteins are also compared with those of known allergens.

In the end, companies decide how much data to submit to FDA to demonstrate that a particular genetically modified food is as safe and nutritious as its non-GMO counterpart. So far, companies have provided sufficient data to make those comparisons, Dietz said. FDA has had no reason to request long-term, repeated-dose toxicity studies in rodents, he added.

“FDA’s approach provides for a rigorous, case-by-case, science-based food safety assessment that is protective of public health,” Dietz stated.

But not everyone agrees with this view, in large part because FDA relies on safety assessments that are conducted by the food industry. These skeptics are the consumers calling for labels on bioengineered food so that they and others can avoid eating GMOs if they so choose.

Critics of the current regulatory system warned the committee that GMO crops will be commercialized in the future with no government oversight. These crops won’t be any less risky than those that do get oversight, said Gregory Jaffe, biotechnology director at the Center for Science in the Public Interest. Of particular concern are crops developed using new techniques such as RNAi and DNA editing, he said.

“The regulatory system needs to be science based and address the potential risks” to human health and the environment, Jaffe emphasized. “If the regulatory system is not a risk-based system, I think the public will lose confidence in the system and therefore lose confidence in the products that might come out of that system to be used by farmers or elsewhere in our food supply.”

Legislation Would Create Certification For GMO-Free Foods

Lawmakers in the House of Representatives are hoping they can help quell the debate over labeling of genetically modified organisms (GMOs) with a bipartisan bill, the proposed Safe & Accurate Food Labeling Act (H.R. 1599).

Introduced on March 25 by Rep. Mike Pompeo (R-Kan.), the legislation would establish a federal program to certify that specific foods do not contain GMOs. This would replace a voluntary verification program now run by a nonprofit group, the Non-GMO Project. Like the current effort, the proposed federal program also would be voluntary.

H.R. 1599 would also prohibit states from enacting GMO labeling laws. Because of this provision, several advocacy groups have dubbed the bill the Denying Americans the Right-to-Know, or DARK, Act. They also say the bill would make it harder for the Food & Drug Administration to require labeling of GMO foods if the agency decided to do so.

Lawmakers discussed the bill at a March 24 hearing of the House Agriculture Committee. Witnesses included representatives from the food industry, a farmer, and others with financial ties to the food and agriculture industries. Every witness supported the notion of a voluntary, federal GMO labeling program. No GMO opponents or GMO labeling advocates, however, were called to testify.

Much of the hearing focused on the impacts that state GMO labeling laws would have on food producers. No state labeling requirements are in effect now, but laws are pending in Connecticut, Maine, and Vermont.

“This growing patchwork of mandatory state laws is creating confusion and driving up the cost of food, harming the most vulnerable Americans,” said Rep. K. Michael Conaway (R-Texas), chairman of the committee. “We are hearing a great deal of misinformation about so-called GMOs and the use of biotechnology in food and agricultural production,” Conaway continued. “These unfounded attacks are not supported by the facts and mislead both consumers and policy-makers.”

H.R. 1599 has support from lawmakers on both sides of the aisle. Eight Democrats and nine Republicans had co-sponsored the bill as of late March.

Opponents of the legislation include environmental activists, small-scale producers, and organic farmers. They support mandatory labeling of GMO foods and argue that FDA’s existing approval system for these products has failed consumers.


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