In November 2012, California voters rejected Proposition 37, a ballot measure that would have required retailers and food companies to label products made with genetically-modified organisms (GMOs), but opponents of the measure might not be able to rest on their laurels.

Genetic modification is defined by the USDA as “the production of heritable improvements in plants or animals for specific uses, via either genetic engineering or other more traditional methods.” While most Americans report they are not concerned or are only slightly concerned about these foods, there has been a gradual and steady shift toward heightened concern.

Back in 2001, 8 percent of adults said they were very or extremely concerned about them. That number doubled to 16 percent in 2012, shown by The NPD Group's Food Safety Monitor. Moreover, as we continue to track these concerns into 2013, the trend only seems to continue.

Concern about these foods is not universal throughout the United States; regional differences come to into play. For example, the Census region where the lowest concern levels are expressed is the West North Central, a region where the agriculture business is deeply important to local economies. This region includes Iowa, Kansas, Minnesota, Missouri, Nebraska, and the Dakotas, where 15 percent of adults in these states are very or extremely concerned about these foods. Media coverage of Proposition 37 in California may have increased awareness of GMOs in food during the election cycle. Twenty-three percent of adults in the Pacific region expressed concern, and that number rose to 25 percent when just looking at consumers within California.

Marketers should also be aware that women, who are more likely to be the primary shoppers and food preparers in the household, are more concerned about GMOs than men. About 22 percent of women are very or extremely concerned about GMOs versus 18 percent for men. This could present some opportunities for marketers whose products are free of GMOs. While no US law requires the labeling of foods made with GMOs, placing a label stating your products are GMO-free could provide some relief to consumers – and in particular, mothers – who consistently express desires to feed their children as healthfully as possible. Such labeling would be akin to products labeled gluten-free even when they are not wheat- or carbohydrate-based. The point of the label is to remove any doubt in the consumer's mind that a potentially unwanted substance is absent from the food or beverage.