OPINION This November, California voters will decide on a question that affects us all: Do we have the right to know what's in the food we're eating and feeding our families?

This high-stakes food fight has become the most expensive issue of the upcoming election. Pesticide and junk-food corporations have already poured $25 million into an effort to defeat Proposition 37, a simple labeling measure that would inform California consumers about whether our food has been genetically engineered.

What is it that these corporations don't want us to know?

Right now, many foods on supermarket shelves, from baby formula to corn chips, contain genetically engineered ingredients that are hidden from consumers. Also called GMOs, these are crops that have been artificially altered in a lab with the DNA of other species in ways that cannot occur in nature.

Numerous studies link genetically engineered foods to allergies and other adverse health effects. But the U.S. government requires no safety studies of GMOs, no long-term health studies have been conducted, and no labeling is required to notify consumers so we can make our own choices about whether we want to eat these foods.

Genetically engineered foods are also linked to serious environmental concerns, including an overall increase in pesticide use, a rise in super weeds that are threatening farm land, and the unintentional contamination of organic crops.

These concerns have led 50 other countries to require GMO labeling. But here in the U.S., the agri-chemical companies have deployed their massive lobby power to stop the federal government and at least 19 U.S. states from passing simple labeling bills.

Now it's up to the voters of California — and the heavy-artillery corporate lobbying campaign is heading our way.

The Yes on 37 Campaign is currently tracking far ahead in the polls. But the voters have not yet been subjected to the wave of deceptive television ads designed to convince us that GMO labeling is too scary or too expensive.

When you see these ads, consider the source. The largest funders of No on 37 are Monsanto and DuPont, two corporations that hardly have a track record of integrity when it comes to truth in advertising. These are the same companies that told us DDT and Agent Orange were safe.

Major funders of the No campaign also include junk-food companies that have a long history of opposing common-sense labels to give consumers information about their food. Look for these companies to spend tens of millions trying to convince voters that adding a few words to food labels will force them to raise the cost of groceries "hundreds of dollars a year."

Over on the Yes on 37 side is a true people's movement made up of millions of moms, dads, and consumers in California, and the many farmers and California businesses that are part of the state's thriving natural and sustainable food industry.

Now is the time and this is our chance to make sure we have the right to know what's in our food. Visit Yes on 37 at Carighttoknow.org to volunteer, donate and stay up to date with the latest news about this historic campaign.

Stacy Malkan is the media director for Yes on 37, the California Right to Know campaign to label genetically engineered foods.