[...] the Senate blocked a controversial measure that would have prevented states from passing initiatives like Prop. 37, such as the GMO labeling law due to roll out July 1 in Vermont.  Days later, General Mills announced it would voluntarily add GMO labels to all of its products; fellow industrial food giants Mars, Kellogg Co. and Conagra quickly followed suit, even though those companies have spent millions to fight such labeling.  Supporters range from groups such as U.S. Right to Know…

Major brands reverse course on genetically modified food labels