One retail grocery chain may be able to do what several states have been trying to do through legislation—require food containing genetically modified ingredients to be labeled. Whole Foods Market announced last week that it would require all GM food sold in its stores to be labeled. Whole Foods Market is the first grocery chain to make such an announcement.

The new labeling requirement would be put in place within five years, said A. C. Gallo, president of Whole Foods. He claimed that the move was inspired by consumer demand. “We’ve seen how our customers have responded to the products we do have labeled. Some of our manufacturers say they’ve seen a 15 percent increase in sales of products they have labeled,” Gallo told The New York Times.

All 339 Whole Food stores in the United States and Canada would be included in the new labeling requirement. Its seven stores in Britain already label products that contain GM ingredients.

The announcement comes within four months of voters rejecting a GM labeling bill in California that would have required all products that contained GM ingredients to be labeled within the state. This would have essentially forced all food manufacturers to rewrite their food labels. Since the Proposition 37 was defeated in November 2012, other states have tried picking up the mantle through various bills with varying success.

Whole Foods’ announcement was met with opposition from the Grocery Manufacturers Association, which issued a statement. “These labels could mislead consumers into believing that these food products are somehow different or present a special risk or a potential risk,” Louis Finkel, GMA’s executive director of government affairs said in a statement, the New York Times reported.

The Biotechnology Industry Organization also issued a statement against Whole Foods.

“BIO fully supports the voluntary labeling of products to meet specific demands of consumers in the marketplace. But BIO does not support attempts to label food in a way that is misleading or that confuses consumers – for example, by suggesting that there is a difference in safety or nutrition between biotech food and organic food, when there is none,” BIO announced in a statement.

Proponents of requiring food manufacturers to label GM ingredients approved of Whole Foods’ announcement and called the move a “game changer.”

“Whole Foods is doing the right thing for consumers by giving them more information about what is in their food,” said Gary Hirshberg, chairman of Stonyfield Farm and board chair of Organic Voices. “We urge other business leaders to work with us to give every American the same right as consumers in 62 other countries. More than 90 percent of Americans want the right to know whether their food contains GE ingredients so that they can make the best choices for their families.”