Whatever the science, consumers are jumpy about genetically modified foods. At least they are in Europe. For years, restaurants and grocery stores have trumpeted their products are GMO free.

“Even McDonalds in Italy and in Great Britain advertises that its products don’t contain any GMOs. So it depresses use of genetically modified foods,” says New York University food studies professor Marion Nestle.

In the U.S., Whole Foods now plans to label products with the GMOs inside. But will our market follow Europe’s lead and shun modified food? American farms grow the most genetically modified foods in the world, and our diet is already full of high-tech grains.

The real test may be price, says Harry Balzer of the NPD Group.

“Nothing will change your behavior faster — short of a food safety issue — than prices. And we will never let food prices rise faster than our incomes,” Balzer says.

A study from Iowa State suggests non-genetically modified foods could end up costing 6 to 10 percent more around the world.