NEW YORK (AP) - Whole Foods says all products in its North American stores  that contain genetically modified ingredients will be labeled as such by  2018.

The company says it's the first national grocery chain to set such a deadline  for labeling foods that contain genetically modified organisms, or GMOs. A  spokeswoman for the supermarket operator said organic foods will not have to  carry the labels since they do not contain genetically modified ingredients by  definition.

Although Whole Foods is known as an organic grocer, it also sells a wide  array of non-organic products.

The use of GMOs has been a growing issue in recent years, with health  advocates pushing for mandatory labeling even though the federal government and  many scientists say the ingredients are safe.