How do we know this? You can thank scientists. In a nutshell: Scientists identify "stable isotopes of carbon from human that bear the signatures, in effect, of the different types of plants that originally took them from the air and introduced them into the food chain." After water, carbon is the most common element in our bodies. Photosynthesis is the only way to get carbon atoms for the molecules necessary to support life. Most plants create compounds that have three carbon atoms, but corn makes compounds that have four carbon atoms (C-4), thus making it easier to preserve and identify. When a C-4 plant goes for more carbon, it takes in more carbon 13 (versus carbon 12). The higher the ratio of carbon 13 to carbon 12 in a person's flesh, the more corn has been in his or her diet or the diet of of the animals he or she ate.
So essentially, even though forty percent of an average Mexican's diet is made up of corn (generally from tortillas), they have a much more varied diet than we do. Even though most Americans believe they have a varied diet, much of it is simply processed corn.
Finding the processed corn in the supermarket is much easier than you might think:
Corn is what feeds the steer that becomes the steak. Corn feeds the chicken and the pig, the turkey and the lamb, the catfish and the tilapia and, increasingly, even the salmon, a carnivore by nature that the fish farmers are reengineering to tolerate corn. The eggs are made of corn. The milk and cheese and yogurt, which once came from dairy cows that grazed on grass, now typically come from Holsteins that spend their working lives indoors tethered to machines, eating corn.
Head over to the processed foods and you find ever more intricate manifestations of corn. A chicken nugget, for example, piles corn upon corn: what chicken it contains consists of corn, of course, but so do most of a nugget's other constituents, including the modified corn starch that glues the thing together, the corn flour in the batter that coats it, and the corn oil in which it gets fried. Much less obviously, the leavenings and lecithin, the mono-, di-, and triglycerides, the attractive golden coloring, and even the citric acid that keeps the nugget "fresh" can all be derived from corn.
To wash down your chicken nuggets with virtually any soft drink in the supermarket is to have some corn with your corn. Since the 1980s virtually all the sodas and most of the fruit drinks sold in the supermarkets have been sweetened with high-fructose corn syrup (HFCS)-after water, corn sweetener is their principal ingredient. Grab a beer for your beverage instead and you'd still be drinking corn. Read the ingredients on the label of any processed food and, provided you know the chemical names it travels under, corn is what you will find. For modified or unmodified starch, for glucose syrup and maltodextrin, for crystalline fructose and ascorbic acid, for lecithin and dextrose, lactic acid and lysine, for maltose and HFCS, for MSG and polyols, for the caramel color and xanthan gum, read: corn. Corn is in the coffee whitener and Cheez Whiz, the frozen yogurt and TV dinner, the canned fruit and ketchup and candies, the soups and snacks and cake mixes, the frosting and gravy and frozen waffles, the syrups and hot sauces, the mayonnaise and mustard, the hot dogs and the bologna, the margarine and shortening, the salad dressings and the relishes and even the vitamins. (Yes, it's in the Twinkie, too.) There are some forty-five thousand items in the average American supermarket and more than a quarter of them now contain corn. This goes for the nonfood items as well-everything from the toothpaste and cosmetics to the disposable diapers, trash bags, cleansers, charcoal briquettes, matches, and batteries, right down to the shine on the cover of the magazine that catches your eye by the checkout: corn. Even in Produce on a day when there's ostensibly no corn for sale you'll nevertheless find plenty of corn: in the vegetable wax that gives the cucumbers their sheen, in the pesticide responsible for the produce's perfection, even in the coating on the cardboard it was shipped in. Indeed the supermarket itself-the wallboard and joint compound, the linoleum and fiberglass and adhesives out of which the building itself has been built-is in no small measure a manifestation of corn.
That's so much stuff! Obviously some of it isn't as important as the rest. If the magazines want to use corn to make their covers glossy, I don't really care. But I do care when it's used in all of my other food. Not only is a lack of variety in a diet unhealthy, but there are other reasons the book explores later as to why so much corn is directly affecting our health. Stay tuned!