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Soft and creamy enough to be put in pies and called dessert, sweet potatoes are also a surprisingly nutritious vegetable. The orange-fleshed tubers are especially high in vitamin A (also called beta-carotene, which is the carotenoid that turns into vitamin A), vitamins C, E, and B6, fiber and manganese. They even contain some iron. Plus, they’re fat-free, relatively low in sodium, and have fewer calories than white potatoes — although they do have more sugar.
Sweet potatoes are one of the best vitamin A sources out there, containing more than 100 percent of the daily recommended intake. Vitamin A is an antioxidant powerhouse, and beta-carotene has been linked to anti-aging benefits, cancer prevention, and helping maintain good eyesight.
While the orange variety is the most common in the United States, sweet potatoes also come in white, yellow, pink, and purple varieties. While the orange and yellow types contain the most vitamin A, the purple sort is an excellent way to get antioxidants.
Here are the nutrition facts for sweet potatoes, according to the U.S. Food and Drug Administration, which regulates food labeling through the National Labeling and Education Act:
*Percent Daily Values (%DV) are based on a 2,000 calorie diet.
|Amt per Serving||%DV*||Amt per Serving||%DV*|
|Total Fat 0g||0%||Total Carbohydrate 23g||8%|
|Cholesterol 0mg||0%||Dietary Fiber 4g||16%|
|Sodium 70mg||3%||Sugars 7g|
|Potassium 440mg||13%||Protein 2g|
So it’s clear that while sweet potato pie might be soul food, sweet potatoes themselves are a whole-body vegetable.
Sweet potatoes are a great source of B6 vitamins, which are brilliant at breaking down homocysteine, a substance that contributes to the hardening of blood vessels and arteries. Sweet potatoes’ potassium content is also helpful for your heart, as it lowers blood pressure by maintaining fluid balance. Potassium is also an important electrolyte that helps regulate your heartbeat.
Controlling blood sugar and maintaining energy
For as sweet as they are, sweet potatoes have a low glycemic index (sugar amount). Unlike processed sugars, sweet potatoes’ natural sugar is released slowly into your bloodstream. This means you won’t get blood sugar spikes but you will get a steady amount of energy. It also means that sweet potatoes could be helpful in regulating blood sugar in people with type II diabetes (scientists are currently looking into it).
As if that weren’t sweet enough, sweet potatoes are a terrific source of manganese. Manganese plays an important role in metabolizing carbohydrates, which helps maintain healthy blood sugar levels and can stabilize your appetite. It’s also helpful in utilizing antioxidants.
Sweet potatoes contain magnesium, the go-to mineral for de-stressing. It promotes relaxation, calm, and a good mood, as well as artery, blood, bone, muscle, and nerve health.
Immunity and anti-inflammatory properties
One sweet potato contains about half our daily recommended intake of vitamin C. Vitamins A and E also support a healthy immune system and are powerful disease-fighting antioxidants. While orange sweet potatoes contain more vitamin A, purple sweet potatoes are packed with the antioxidants cyanidin and peonidin. All of these pigment-related antioxidants have excellent anti-inflammatory benefits, which are useful for overall health as well as inflammatory disorders, such as arthritis.
Skin and hair
Vitamin A can help protect against sun damage, and vitamins C and E are well-known “beauty supplements.” They encourage healthy, glowing skin and collagen growth.
Sweet potatoes are a good source of dietary fiber, which aids in maintaining a healthy digestive tract and helps keep you regular.
The NIH reports that some studies have suggested that beta-carotene may reduce the risk of breast cancer in pre-menopausal women, ovarian cancer in post-menopausal women.
If eaten in moderation and prepared in a healthy way (that means not just indulging in sweet potato fries), sweet potatoes are a nutritious, delicious food that should pose no significant health risks. But for a vegetable, they are high in carbohydrates — 23 grams per medium sweet potato — and calories — about 100 calories vs. 45 calories in broccoli.
While the vitamin A in sweet potatoes has numerous benefits, if consumed in daily abundance, your skin could turn yellow or orange. This side effect should decrease if you cut down on sweet potato consumption.
People with a history of kidney stones may want to avoid eating too many sweet potatoes, as the vegetable contains oxalate, which contributes to the forming of calcium-oxalate kidney stones. Furthermore, sweet potatoes contain potassium and phosphorus, which is something that those with chronic kidney disease may want to avoid.
Given that sweet potatoes are, in general, very nutritious, you don’t need to cut them out of your diet unless a doctor advises it.
Yams vs. sweet potatoes
Sweet potatoes and yams are often used interchangeably in recipes, but they are quite different and are not even related botanically. Sweet potatoes are members of the morning glory family, while yams are closely related to lilies and grasses. Yams are native to Africa and Asia, and there are more than 600 varieties. Compared to sweet potatoes, yams are starchier and drier.
Why the confusion? According to the Library of Congress website Everyday Mysteries, sweet potato varieties are classified as either "firm" or "soft." In the United States, the firm varieties came first. When soft varieties were first grown commercially, there was a need to differentiate the two kinds. African slaves had been calling the soft sweet potatoes "yams" because they resembled the yams they knew in Africa. Today, the USDA requires labels with the term "yam" to be accompanied by the term "sweet potato." Unless you are specifically searching for yams, which can be found in international markets, you are probably eating sweet potatoes!
As for nutritional benefits, the potato is more powerful. Sweet potatoes and yams are both healthy foods, and they look similar. Sweet potatoes, however, have higher concentrations of most nutrients and more fiber.
Sweet potato facts
Sweet potatoes are roots, compared to regular potatoes, which are tubers (underground stems).
Sweet potatoes are native to Central and South America and have been grown for at least 10,000 years.
Christopher Columbus took sweet potatoes to Europe after his first voyage to the New World in 1492.
By the 16th century, Spanish and Portuguese explorers had taken sweet potatoes to the Philippines and to Africa, India, Indonesia and southern Asia. Around this same time, sweet potatoes began to be cultivated in the southern United States.
George Washington grew sweet potatoes at Mount Vernon.
George Washington Carver developed 118 products from sweet potatoes, including glue for postage stamps and starch for sizing cotton fabrics.
Sweet potatoes are the official vegetable for North Carolina. North Carolina is the leading producer of sweet potatoes in the United States, producing about 40 percent of the national supply.
China grows about 80 million tons of sweet potatoes each year, Africa produces about 14 million tons, Central and South America about 2 million, and the United States about 1 million tons.