What’s the debate over labeling GM foods?

Traditionally in the United States, companies have been able to decide for themselves whether to disclose that their foods contain genetically modified ingredients. But that may soon change.

In April 2014, the Vermont legislature passed the first state law to require labels on all foods with genetically engineered ingredients. The law is scheduled to take effect on July 1, 2016, although food companies are almost certain to challenge it in court.

It’s unclear whether Vermont alone can force US companies to start labeling GM foods — the state is tiny enough that firms could simply stop selling any foods with canola oil, soy lecithin, dextrose, and so forth in Vermont altogether. But in recent years, other states have also been mulling labeling laws.

Maine and Connecticut, for instance, have passed GM labeling laws — but those are contingent on other states also passing their own laws. Meanwhile, ballot initiatives have been introduced in bigger states like California, Washington, Colorado, and Oregon to require labels on all GM foods. But those proposals have been voted down so far.

Arguments for labeling: Those in favor of labeling laws, including organic food companies and food activists, argue that people have a right to know what’s in their food. Some critics of GM foods, like Tom Philpott, have argued that labeling laws could force transparency on an industry that tends to be dominated by just a few large corporations like Monsanto and Dupont.

Arguments against labeling: Those opposed to the laws, including various seed and biotechnology giants, argue that the law could lead to higher prices at the grocery store or frivolous lawsuits against food companies.

Meanwhile, some scientists argue that labeling laws could demonize genetically modified foods in a way that’s disproportionate to the risks involved. UC Berkeley’s David Zilberman worried that labeling laws might “create a stigma effect” that will hinder future research into using GM foods to improve nutrition or help ameliorate the effects of climate change.

Labeling around the world: Currently, some 64 countries require labeling of GM foods, including Japan, Malaysia, New Zealand, and Australia:

Some studies of labeling laws in Netherlands and China found they did not substantially affect consumer behavior. That said, after the EU required labeling in 1997, many retailers in Europe removed foods containing genetically modified ingredients from their shelves.