Maybe you've seen them before, maybe not: purple carrots, yellow tomatoes, black rice, red potatoes.

Heirloom varieties.

What does this mean?

An heirloom plant is one that has been grown for a long time in human history, but is no longer commonly grown in modern large-scale agriculture.

These are not new hybrids. They have been around for centuries. Not that hybridization is necessarily bad, but lest you fear that these have ben concocted in a lab and tomatoes are supposed to be red, let me reassure you that tomatoes have been green, yellow, orange and red for a very long time.

Modern day agriculture is very focused on uniformity. As a result, large-scale operations tend to grow only one variety of corn, potato, tomato etc. While this may be effective at producing french fries that all look the same, we are missing out on a multitude of benefits that various varieties of plants have to offer. Not all potatoes are created equal, for example. While the common New and Russet potatoes get a bad rap, purple potatoes are loaded with antioxidants.

An article from Rodale with more information: Purple Potatoes: Your New Blood Pressure Medicine

One of the keys to a healthy diet is variety. We need to consume a variety of foods in order to obtain the vast array of micronutrients that our bodies need. A great way to do this is to add variety within the foods that you already eat. Is rice standard in your diet? Try cooking with different types of rice. There are dozens of rice varieties, each with their own unique flavor profile that can add to your health and to the deliciousness of your meal.

More information about the greatness of black rice:

District Avenue Nutrition: White rice, Brown rice, What’s BLACK rice?

Here's another reason to care:

In general, it is hard to find heirloom varieties at standard grocery stores. More health conscious grocery stores, however, do offer a lot of heirloom options and farmers markets are teeming with them. You see, the reason that there are, or at least were, so many different varieties of each plant species is that plants can adapt to be grown in different regions with different conditions. Through the generations, farmers keep the seeds that thrive and pass those on to their children. Thus, local heirloom varieties have been adapted over the years to be successful in your local area. That means that these plants by nature require less external help to deal with pests and weather because they have evolved to be better suited to the climate. Unfortunately, due to the monoculture mentality of large-scale agriculture, many heirloom varieties have been lost. We are losing Agrobiodiversity.

Some numbers from the Food and Agricultural Organization of the United Nations:

[Box 5] 100 YEARS OF AGRICULTURAL CHANGE: SOME TRENDS AND FIGURES RELATED TO AGROBIODIVERSITY

*Since the 1900s, some 75 percent of plant genetic diversity has been lost as farmers worldwide have left their multiple local varieties and landraces for genetically uniform, high-yielding varieties.
30 percent of livestock breeds are at risk of extinction; six breeds are lost each month.
Today, 75 percent of the world’s food is generated from only 12 plants and five animal species.
Of the 4 percent of the 250 000 to 300 000 known edible plant species, only 150 to 200 are used by humans. Only three - rice, maize and wheat - contribute nearly 60 percent of calories and proteins obtained by humans from plants.
Animals provide some 30 percent of human requirements for food and agriculture and 12 percent of the world’s population live almost entirely on products from ruminants.

Source: FAO. 1999b http://www.fao.org/docrep/007/y5609e/y5609e02.htm

We have already lost a lot, but we can preserve what we have. Buy heirloom varieties and support the use of locally cultivated seeds.

Eating heirlooms can be easy substitutions/additions. Next time you have a veggie tray at an event, try throwing in some purple and white carrots beside the orange ones. You'll have the most beautiful display and be helping everyone to eat the rainbow!