Although white potatoes are the most-consumed vegetable in America, the sweet potato lags behind and is often confused with the common yam, which is actually a different vegetable entirely. Overlooking the sweet potato or confusing it with something else is a mistake because it may just be the world’s most healthful food.
It is a perennial that is grown as an annual and springs forth from underground roots with stems that can be as long as twenty feet. The leaves vary in size, shape and color but usually are green with purple markings. They also produce flowers that are white and pale purple, but these rarely appear.
The orange-colored tuber probably originated in Central or South America, though they no longer grow wild in those regions. It is believed that the sweet potato has been cultivated by those living in the areas for more than 5,000 years, and some fossils in the Andes date the sweet potato to activities dating back 8,000 to 10,000 years. It was the perfect migratory food, compact, nutrition-dense and delicious, which is why people likely carried it with them on their explorations in those early times. It gradually spread from the Americas across the Pacific to New Guinea, Polynesia, Indonesia and New Zealand.
Christopher Columbus brought back sweet potatoes when he first visited the Americas, which spread through Spain and gradually throughout the warmer regions of Europe. They were then brought to the Philippines by Spanish explorers and soon arrived in Africa and the South Pacific, thanks to the Portuguese.
Today, sweet potatoes are a major crop around the world. Some 80 million tons are grown in China while Central and South America grow 2 million tons, Africa 14 million tons, and the United States about 1 million tons. Most of the United States' sweet potatoes are grown in Southern states, with North Carolina a particular hotbed of sweet potato cultivation.
Naturally, with that sort of demand, the sweet potato is a food staple in many countries. Not only is the tuber delicious for its fruit, but the greens are also edible and are an important food source for those in Asia and Africa.
There are more than 6,000 varieties of sweet potato known to exist, many unique to certain countries or regions. The United States has 25 varieties, available in yellow, orange, red, brown and white flesh. Those with white or pale yellow flesh are less sweet than their orange, pink or red flesh cousins. They also don’t have the same amounts of beta-carotene, the vitamin that powers the sweet potato nutrition engine and are more mealy but firmer.
Eight Sweet Facts
Here are eight things you may not have realized about sweet potatoes.
1) They contain vitamins C, A and B6 – Vitamin C boosts the immune system and plays a role in blood cell formation and bone and tooth development. It also may help reduce stress. B6 helps control homocysteine levels, which has been linked to many degenerative diseases. And Vitamin D is essential for boosting the immune system and fighting seasonal affective disorder.
2) Sweet potatoes have iron and magnesium – Iron helps red and white blood cell development, boosts energy and helps metabolize protein. Magnesium is the anti-stress mineral, helping blood, bones, hearts, muscles and nerves function at optimal levels.
3) Sweet potatoes have potassium – This important electrolyte helps regulate the constant heartbeat and nerve signals in the body. Every time you take a breath, it’s because you have potassium levels helping muscle contractions.
4) Sweet potatoes are a slow-release sugar – Yes, they have natural sugars, but they don’t crash the system like a candy bar. These natural sugars are slowly released into the bloodstream, keeping blood sugar even.
5) They are versatile – You’ll never get tired of the various ways you can eat a sweet potato, which makes them a staple in many countries with diverse cultures. They are good roasted, in stews, soups, salads and as an accompaniment in wraps. They also enhance baked goods.
6) They have glycosides – These are molecules that researchers have discovered have antibacterial and antifungal properties.
7) They may have anti-cancer properties – Concentrated carotenoids in the sweet potato are powerful antioxidants that may play a role in reducing cancer. A Harvard study found a 32 percent reduction in lung cancer among those who had a healthy, carotenoid-rich diet.
8) A sweet potato by any other name – Most United States groceries sell sweet potatoes, not yams. Commercial production of yams is negligible. So even if the sign claims they sell yams, it’s likely a sweet potato.
Storing and Preparing
When you go shopping for sweet potatoes, choose firm ones that don’t have bruises, soft spots or cracks. If your supermarket unwisely put them in a refrigerated area of the produce section, leave them alone. The cold will alter their taste and make them bitter. You want a sweet potato, not a bitter potato!
After bringing home your bounty, keep the sweet potato in a cool, dry, dark and well-ventilated place. They will usually stay fresh for about 10 days. A brown paper bag with multiple air holes is the ideal place to put them. Just make sure the cupboard where you store them does not absorb excess heat from the stove or other sources.
If you buy an organic sweet potato, you can eat it as is; some stores treat them with dye or wax, so you’ll likely want to peel the skin off before consuming it. You can do that after cooking them. Just make sure to prepare them after cooking or cutting because they darken on contact with air. If you prep them before cooking, keep them immersed in water to prevent oxidation.
How you enjoy your sweet potato is a matter of personal taste. Just keep in mind that they’re not just for Thanksgiving or other holidays. The sweet potato is a perfectly good dish to serve with just about any meal.