Foods That Heal

SWEET POTATO

SWEET POTATO

SWEET POTATO

The sweet potato (Ipomoea batatas) is not a member of the potato (Solanaceae) family but rather of the (Convolvulaceae), or morning glory, family. In the United States, we tend to call the darker, sweeter sweet potato a yam. In actuality it is not a yam, but is in fact a variety of sweet potato.

There are nearly 400 sweet potato varieties. Their flesh may be white, yellow, or orange, and the thin skin may be white, yellow, orange, red, or purple. Some are shaped like a potato, being short with rounded ends, while others are longer with tapered ends.

Sweet potatoes are grouped into two different categories depending upon the texture they have when cooked: firm, dry, and mealy, or soft and moist. In both types, the taste is starchy and sweet, but different varieties have different, unique tastes.

HISTORY

Sweet potatoes are native to Central America. They have been consumed since prehistoric times, as is evidenced by sweet potato relics dating back to 10,000 years that have been discovered in Peruvian caves, making them one of the oldest vegetables known.

As with other foods indigenous to the western hemisphere, Christopher Columbus was the first to bring sweet potatoes to Europe. Spanish and Portuguese explorers in the 16th century took sweet potatoes to Africa, India, Indonesia, and southern Asia. Early settlers in the south eastern United States begin cultivating sweet potatoes, making them a staple food in this region even today.

In the mid 20th century, the orange fleshed sweet potato was introduced to the United States and given the name “yam” to distinguish it from the white fleshed sweet potato to which most people were accustomed. The name “yam” was adopted from nyami, an African word for the root of the Dioscorea genus of plants, which are considered to be true yams. The US Department of agriculture mandates that the moist-fleshed, orange-colored sweet potatoes that are labeled as “yams” also be accompanied by the label “sweet potato” in an attempt to distinguish between the two, but for many people this does not help to clarify the distinction between these very different root vegetables. Yet once you experience the distinct taste and texture of a real yam, you will definitely know the difference, appreciating each of these root vegetables for their unique qualities.

Sweet potatoes are a featured food in many Asian and Latin American cuisines. Today, the main commercial producers of sweet potatoes include China, Indonesia, Vietnam, Japan, India, and Uganda.

NUTRITIONAL HIGHLIGHTS

Sweet potatoes are an excellent source of carotenes. In general, the darker the variety of sweet potato, the higher in concentration of carotenes. Sweet potatoes are also a very good source of vitamin C and B6. In addition, sweet potatoes are a good source of manganese, copper, bio town, pantothenic acid, B2, and dietary fiber.

HEALTH BENEFITS 

Sweet potatoes contain unique root storage proteins, which have been shown to exert significant antioxidant effects. In one study, these proteins had about 1/3 of the antioxidant activity of glutathione -one of the body’s most important internally produced antioxidants. The presence of these proteins, along with the high content of carotenes and vitamin C, makes sweet potatoes a valuable food for boosting antioxidants in your body.

Unlike many other starchy vegetables, sweet potatoes are classified as an “anti-diabetic” food. Animal studies have shown that sweet potatoes actually help stabilize blood sugar levels and improve the response to the hormone insulin.

SELECTION & STORAGE

Use only high-quality sweet potatoes that are firm and display the characteristic features of its variety. Remember, the darker the variety, the higher the carotene contact. Avoid wilted, leathery, or discolored sweet potatoes, especially those with a green tint.

Sweet potatoes should be stored in a cool, dark, and well ventilated place, where they will keep fresh for up to 10 days. They should be stored loose and not kept in a plastic bag. Keep them away from exposure to sunlight or temperatures above 60°F, since this will cause them to sprout or ferment. Uncooked sweet potatoes should not be kept in the refrigerator.

PREP TIPS

If using organically grown sweet potatoes, wash them under cold running water and gently scrub with a soft vegetable brush right before cooking. If organically grown sweet potatoes are not being used, soak them in a mild solution of additive free soap or produce wash, then either peel or scrub thoroughly with a natural bristle vegetable brush under cool running water. Remove any deep bruises with a paring knife. If you elect to peel the sweet potatoes, do so with a vegetable peeler and try to remove only a thin layer of the skin to retain as much nutritional value as possible.

If you cannot cook them immediately after cutting or peeling, place them in a bowl of cold water with a little lemon juice to prevent discoloration. Also, avoid cooking potatoes in iron or aluminum pots and avoid using a carbon steel knife to cut them, as these metals can also cause them to discolor.

LET'S EAT

  • Sweet potatoes can be prepared in ways similar to potatoes.
  • For a delicious hot dessert, purée cooked sweet potatoes with banana, maple syrup, and cinnamon, top with chopped walnuts.
  • Make sweet potato chips by finely slicing sweet potatoes, then lightly coat with olive oil and your favorite seasonings. Bake the sweet potato chips at 300°F until crispy, or approximately 20 minutes.
  • Cubed sweet potatoes can be added to any vegetable stir fry.

SAFETY 

Sweet potatoes contain high levels of oxalate. Individuals with a history of calcium oxalate containing kidney stones should limit consumption

RESOURCES

  • The Encyclopedia of Healing Foods by Michael Murray, ND

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