Since 1994 there's been an unnatural new player on our grocery store shelves. GMO is short for "genetically modified organism." It describes foods grown from seeds that have been altered through biotechnology to express certain desirable traits, such as pest resistance. Increasing concerns over genetically modified crops have prompted legislation in more than thirty states, where advocates are calling for clear labeling on all food that comes from genetically altered seeds. Labeling foods containing genetically modified ingredients will enable us to choose to avoid them. It is a policy long overdue.

When it comes to food crops, there are three kinds of seeds: ancient, hybrid, and genetically modified (GM). The original seeds, called "heirloom" or "heritage," are ancient seeds improved over time by selective breeding. Seeds from these plants will be the same from one generation to the next. Hybrid seeds are a cross between two or more heirloom varieties, bred for qualities like increased vigor, greater yield or shorter growing season. Hybrid seeds often bring unique advantages, but saved seeds will not "come true"; they will revert to the parent plants. In both cases, though, humans have been manipulating seeds in these two ways for generations. We have been selectively breeding for thousands of years. The ancestor of today's corn ("maize") would not be recognizable as corn.

Gluten-free foods seem to be popping up everywhere. Is this just another diet fad?

Just five years ago, asking your server for gluten-free choices would get you the proverbial blank stare. Today it's more likely to elicit a menu page of choices. Family chains, some fast-food outlets, even ball park vendors, now include gluten-free options. Why are millions of Americans suddenly eschewing wheat? Is this just another craze, like the grapefruit diet? What exactly is gluten, anyway?

Let's start at the core, or more precisely, the endosperm. Gliadin and glutelin combine to  form gluten, a protein bound with starch in the endosperm of grains — specifically wheat, rye, barley and triticale (a hybrid of wheat and rye). (Maize, rice and other members of the grass family also contain proteins sometimes referred to as gluten; the proteins are dissimilar and most gluten-sensitive people don't react to them. New research, however, is showing that corn can cause problems for gluten sensitive individuals).