It's no secret that people are nervous about foods made from genetically modified organisms. A July Gallup poll found that 48 percent of respondents believed that GM foods "pose a serious health hazard," compared to 36 percent who didn't. California voters may have rejected a ballot initiative to require labeling of GM foods last fall, but a New York Times survey found overwhelming support for mandatory labeling on the packaging of GM foods.

Within the scientific community, the debate over the safety of GM foods is over. The overwhelming conclusion is, in the words of the American Association for the Advancement of Science, that "consuming foods containing ingredients derived from GM crops is no riskier than consuming the same foods containing ingredients from crop plants modified by conventional plant improvement techniques." Major scientific and governmental organizations agree. The U.S. National Academy of Sciences found that "no adverse health effects attributed to genetic engineering have been documented in the human population," and a report issued by the European Commission made the same claim. The World Health Organization has concluded that GM foods "are not likely, nor have been shown, to present risks for human health."

What evidence will it take to convince the public that GM foods are as safe as non-GM foods?

The scientific literature backs this up. In February, the Journal of Agricultural and Food Chemistry published a literature review covering 20 years of safety studies. The authors found "overwhelming evidence" that using biotechnology to genetically modify crops "is less disruptive of crop composition compared with traditional breeding, which itself has a tremendous history of safety." An overview of safety studies appearing this month in Nature Biotechnology noted that, despite disagreement over a need for more long-term safety studies, both critics and proponents of GMOs agree that so far "genetically modified foods have failed to produce any untoward health effects."

In other words, the scientific consensus is that GMOs do not pose risks to our health or the environment that are any different from the risks posed by the non-GM crops created with modern breeding programs.

The discrepancy between the public debate over GM foods and the debate within the scientific community has left many scientists puzzling over the question: What evidence will it take to convince the public that GM foods are as safe as non-GM foods?

The editors at Nature Biotechnologyargue that evidence is not the problem. The issue is that, so far, people have no reason to believe GM foods are being created for their benefit. Changing negative attitudes will "require a concerted and long-term effort to develop GM foods that clearly provide convincing benefits to consumers—something that seed companies have conspicuously failed to do over the past decade." The question of benefits has been buried because the GMO debate has been framed around the unhelpful distinction between GM and non-GM foods. Instead of asking if GM foods in general are less safe, the editors argue, we should be focused on the specific risks and benefits of individual products, whether they are GM or not.

A focus on the risks and benefits of all new crops could move the debate in a direction that would prompt scientists, companies, and regulators to more clearly justify the role GMOs play in our food supply. To date, consumers nervous about GMOs have been given little reason to think that companies like Monsanto are designing GM crops to solve any problem other than the one of patents and profits. As journalist Mark Lynas put it in his rousing defense of GM foods, for most people GMOs are about a "big American corporation with a nasty track record, putting something new and experimental into our food without telling us."

But many researchers working on GM crops are in fact trying to solve important problems, such as feeding a growing population, keeping food prices affordable worldwide, making healthier fruits and vegetables widely available, confronting the challenging growing conditions of a changing climate, saving Florida's oranges or Hawaii's papaya from pests, and fighting malnourishment in the developing world. For many of these problems, genetic engineering is faster, more cost-effective, and more reliable than conventional breeding methods.

Our society's unresolved controversy over GMOs is not about safety; it's about whether we have an acceptable process in place to ensure that our health is not put at risk for the sake of biotech's bottom line. Researchers, biotech companies, and regulators need to settle on an appropriately rigorous, transparent, and independent safety testing process for all new crops, one whose methods and results are publicly available. Currently, as the Nature Biotechnology review notes, safety assessments in the U.S. are a patchwork affair with weak legal underpinnings. But for GM solutions to our food challenges to be widely accepted, the public needs to know that they are not being coerced into eating something whose risks and benefits are unknown.