Step into a modern grocery store and it would be understandable if you assumed that there are more foods available today than ever before.  But, that assumption would be wrong!

While it's true that stores today bring more organic and ethnic foods to consumers - what with whole aisles devoted to Asian and Mexican foods, organic "fair trade" vegetables, and the like - it's also a fact that there are less varieties of foods available to American consumers than any other time in our history.

Sure, the average grocery store may carry six or seven different types of apples, some of them grown in America, but a century ago, Americans grew and ate more than 15,000 named varieties. Today you'd probably be lucky if you could find the trees representing the 1,500 kinds remaining in North America, according to Gary Paul Nabhan, editor of Renewing America's Food Traditions.

Nabhan's book lists over 1,000 foods that are disappearing from the shelves and palates of American consumers.

Some of the changes have been brought on by changing tastes - but some also have their origins to mass-merchandising.

For instance, the sweet and flavorful black sphinx date, a new variety that emerged in Arizona in the 1920s, fell out of favor in part because its delicate skin caused it to spoil during long shipments. Traditional food varieties also can be contaminated by cross pollination with genetically modified crops, changing their taste and character. Disease, over-harvesting and climate changes can take a toll over time.

It also appears that as the country homogenized, so did our tastes.  For instance - a food like "pizza" used to be made differently in just about every community across the nation - in a wide variety of shapes, flavors, and styles.  While some iconic varieties of pizza remain (think Chicago-style, California-style, etc) - the food has - for the most part - been reduced to looking and tasting alike thanks to chain restaurants and cookbooks.

Food observers challenge people to think outside of their usual menu and try to incorporate more variety into their diet.  There are many ways that you can help to stem the tide;  Visiting local farmers markets and trying one different ingredient or recipe a week can help.