What you must know about GMOs and your health

Limited research and no mandatory labeling for genetically modified organisms leave consumers in the dark

Published: October 23, 2014 04:45 PM

One of the major arguments that supporters of genetically modified organisms make is that Americans have been eating foods containing those ingredients for more than 15 years, and there's no credible evidence that people have been harmed. The Grocery Manufacturers Association—whose members include genetically modified seed manufacturers and food and beverage companies—has stated that GMO ingredients are "safe for people and our planet" and "have a number of important benefits."

What they don't say is that these are assumptions, not facts. "Those who advocate for the use of GMOs like to point out that there's no evidence of harm," said Michael Hansen, Ph.D., senior scientist at Consumers Union, the advocacy and policy arm of Consumer Reports. "But that's not the same as having evidence that shows that GMOs are safe. The studies needed to determine long-term safety haven't been done. There's a lot we don't know."

New tests by Consumer Reports find genetically modified organisms in many packaged foods. And read more about food safety in our food safety & sustainability guide.

Genetically modified organisms are created in a lab by altering the genetic makeup of a plant or animal in ways that would not happen in nature. Studies in animals suggest that GMOs may cause damage to the immune system, liver, and kidneys. Animal studies commonly are used to help assess potential human health risks from exposure to substances such as synthetic chemicals and food additives.

While more research is needed on long-term effects, many experts agree that genetic modification has the potential to introduce new allergens (or increase levels of existing ones), toxins, and nutritional changes in foods. Because of such risks, a joint commission of the World Health Organization and the Food and Agriculture Organization of the United Nations has established a protocol for evaluating the safety of GMOs. European countries and other developed nations incorporated those guidelines into their mandatory premarket safety assessments for genetically modified organisms. But in the U.S., the Food and Drug Administration doesn't require any safety assessments before GMOs are used in food.

The FDA invites companies to submit their genetically modified organism data for safety review. Nevertheless, there's still no legal barrier to prevent foods containing ingredients that come from potentially risky genetically modified crops from ending up on American supermarket shelves.

More than a decade ago, for example, DuPont inserted genes from Brazil nuts into soybeans to improve the soybeans' protein content. Tests DuPont conducted as it prepared the new soybeans for the market found that they were likely to cause serious acute reactions in people with Brazil nut allergies.  After critics raised concerns, DuPont voluntarily discontiuned the product. But without mandatory premarket safety approvals in place, there's no guarantee all companies will always act responsibly, or adequately study the long-term health effects.

Consumer Reports believes that when it comes to food, consumers deserve a high level of safety assurance and have the right to know what they're eating. That's why we support mandatory safety assessments and mandatory labeling, something that is required in more than 60 other countries, but not in the U.S.

Some states have passed genetically modified organism labeling legislation and this fall, voters in Oregon and Colorado are being asked to decide if they want GMO labeling in their states. "Labeling laws allow people to decide for themselves if they want to buy products that contain GMO ingredients," Hansen said. "What's more, when you know which foods have GMOs, it makes it easier to do the kind of studies that can determine whether GMOs have effects on human health."

—Andrea Rock

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