5 On Your Side

GMOs prevalent in many foods, but labeling not required

Posted October 27, 2014 5:04 p.m. EDT
Updated October 27, 2014 5:23 p.m. EDT

Label-conscious food shoppers may look for things such as vitamin, fiber and sugar content in their purchases, but what they won’t see is how many genetically modified organisms (GMOs) are in their food.

That’s because GMO labeling is not required in the United States.

In addition, GMOs are not required to be proven safe before they’re used in food. About 90 percent of corn produced in the United States is genetically modified. Same with soybeans.

Some animal studies suggest that GMOs may cause liver, kidney and immune system damage, but scientists say there’s not enough research to determine how GMOs can harm humans.

Consumer Reports recently tested a variety of soy and corn products for GMOs, from cereals to snack bars and soy-based infant formulas.

"Unless they were labeled organic, the vast majority of products without a specific claim regarding GMOs actually did contain a substantial amount,” said Dr. Michael Crupain, director of Consumer Reports' Food Safety and Sustainability Center.

Foods labeled ‘natural’ are also not GMO exempt.

"There is no legal definition for the claim 'natural' on processed foods,” Crupain said. “Virtually all the samples we tested that said ‘natural,’ but didn't make claims about being organic or non GMO, in fact contained a high percentage of GMOs."

Crupain said the most reliable labels for avoiding GMOs are ‘non-GMO project verified’ or ‘organic.’

GMO labeling and safety assessments are mandatory in other major developed countries, including China, Japan and the European Union.

"Scientists around the world agree that GMOs have the potential to introduce allergens and create other unintended changes that may affect health," said Dr. Michael Hansen, senior scientist at Consumers Union and an authority on genetic engineering.

The use of genetically modified seeds has steadily grown over the last two decades, resulting in about a 10-fold increase in farmers' use of glyphosate, a weed killer better known as Roundup. 

But this created a new problem for farmers - a rising number of "super weeds" that are immune to glyphosate.

"This defeats one of the major reasons why GMOs were introduced in the first place," Hansen said.

Vermont recently passed legislation requiring GMO labeling on foods. Labeling requirements are on the ballot in Oregon and Colorado this fall. Dozens of other states are considering similar legislation.

A similar bill was introduced in North Carolina a few years ago, but nothing happened with it.