Sweet Potatoes

Cultivation of sweet potatoes originated in Central and South America. Introduced to the Western nations by Columbus, sweet potatoes, often (wrongly) called yams, belong to the Convolvulaceae, or morning glory plant family. Yams (from the African word nyami) are from the Dioscoreae family and have only one embryonic seed leaf (monocot), while sweet potatoes have two (dicot).

 

There are about 400 varieties of sweet potato, some more rare than others, differentiated by their skin and flesh color, ranging from cream, yellow and orange to pink or purple. Oxidation turns them dark in spots after peeling, but don’t worry — the quality of the vegetable isn’t affected.

Baked sweet potatoes are a lovely alternative to plain white, especially with butter, salt and pepper. Sweet potato chips and fries (cooked in coconut oil) are tasty snacks. Baking isn’t recommended because this method can cause the sweet potato to lose many of its antioxidants and a whopping 80% of its vitamin A content.

The health benefits of sweet potatoes may even surpass their reputation as a holiday favorite, having unique attributes not seen in other plant-based foods.

Health Benefits of Sweet Potatoes

The deep orange color of sweet potatoes indicates the presence of beta-carotene, shown by a 2011 study to be especially rich in sweet potatoes. Its vitamin A content is also is impressive, providing 709 micrograms per 100-gram serving. The 2.4 milligrams of vitamin C and 30 milligrams of calcium aren’t too bad either.

Two key antioxidant enzymes in sweet potatoes are copper/zinc superoxide dismutase and catalase. Research published in the International Journal of Health Sciences noted that superoxide dismutase “acts as a good therapeutic agent against reactive oxygen species-mediated diseases.” Another study showed that superoxide dismutases may help lower the risk of mitochondrial dysfunction.

In light of their high sugar content, a surprising fact about sweet potatoes is their ability to help regulate blood sugar, even in Type 2 diabetics. Research has verified that sweet potato extract can increase adiponectin, a protein hormone produced by your adipocytes, to regulate the way your body metabolizes insulin.

However, make sure you consume sweet potatoes in moderation, as some varieties are high in fructose. The U.S. Department of Agriculture (USDA) notes that sweet potatoes have 4.18 grams of sugar per 100-gram serving. To give you an overview of the other nutrients in sweet potatoes, refer to the table below.

Sweet Potatoes Nutrition Facts Serving Size: 3.5 ounces (100 grams), raw
	Amt. Per Serving	% Daily Value*
Calories	86
Total Fat	0.05 g
Saturated Fat	0.018 g
Trans Fat
Cholesterol	0 mg
Sodium	55 mg
Total Carbohydrates	20.12 g
Dietary Fiber	3 g
Sugar	4.18 g
Protein	1.57 g
Vitamin A709 µg	Vitamin C	2.4 mg
Calcium30 mg	Iron	0.61 mg

Studies Done on Sweet Potatoes

Studies show that heat processing methods for sweet potatoes, such as steaming or boiling, not only releases beta-carotenes, but also makes them more accessible to the body, possibly because heat causes a disruption in the microstructure of the tissue.

Other studies have demonstrated that sweet potato extract has anti-obesity and anti-inflammatory potential, helping reduce inflammation in brain tissue and nerve tissue throughout the body.

Anthocyanidins, responsible for the pigmentation of deeply hued vegetables like purple sweet potatoes, contain flavonoid and antioxidant properties. Studies have attributed anthocyanidins for suppressing colon and breast cancer cell growth.

Other polyphenols in purple sweet potatoes include cyanidins and peonidins, which a study indicated have strong counter effects on cancer cell growth. Interestingly, these anticancer compounds are more concentrated in the sweet potato itself than the skin.

Another study showed both benign and cancerous colorectal tumors to multiply in the presence of substances such as pyridine (structurally related to benzene and ammonia), and dimethylhydrazine (a rocket propellant), but these toxins were inhibited by introducing purple sweet potato. The results “clearly demonstrated” that purple sweet potato has the capacity to help reduce colorectal carcinogens.

Sweet Potatoes Fun Facts

Sweet potatoes were introduced to the Western world when Christopher Columbus returned to Spain. However, what’s interesting is that the vegetable already crossed the Pacific even before he landed on the shores of America. According to a report from the NPR, there’s evidence of sweet potatoes in Polynesia that came from South America almost 400 years before the arrival of the Western explorers.

In 1740s, “sweet” potatoes became known as such in the American colonies to differentiate them from white “Irish” potatoes.

Summary

Don’t just serve deliciously honeyed or savory sweet potatoes on holidays; enjoy them regularly in a plethora of ways — sautéed, baked, steamed or fried — because they’re good for you! Antioxidants take the bite out of free radicals roaming throughout your body looking for a place to cause damage, but that’s just one of the tremendous health benefits you get from sweet potatoes. Anthocyanidins, which give them deep pigments such as orange and purple, contain flavonoid and cancer-fighting, anti-inflammatory, antioxidant and antimicrobial properties.

Sweet potatoes are abundant with beta-carotenes, along with copper/zinc superoxide dismutase and catalase, adiponectin for balancing your insulin and impressive doses of vitamin A, plus good levels of vitamin C and potassium. Studies have also shown that sweet potatoes may help reduce your risk of cancer, particularly in the colon and breast.

Including a serving of healthy fat with every meal significantly increases your beta-carotene uptake from sweet potatoes, easily done by using 1 tablespoon of extra virgin olive oil or coconut oil.