the super benefits of sweet potatoes

Jill Bridges, SATI STAFF

When putting together a healthy diet plan, starchy carbohydrates typically are not on the list. That said, sweet potatoes are much healthier than their white potato counterpart, and they offer many health benefits that other starches can’t compete with. In addition, sweet potatoes are a nutrient-dense alternative to traditional grains in gluten-free or lower-carb diets.

Not only do sweet potatoes rank low on the glycemic index, which limits their impact on your blood sugar, but they also offer many vitamins, minerals, and antioxidants that help with weight loss, healthy skin, healthy cholesterol, and cancer prevention. The impressive nutrient profile and array of health benefits of sweet potatoes makes them a valuable addition to your healthy diet.

Learn more about the super sweet benefits of sweet potatoes.

Sweet potato nutrition

One cup of sweet potatoes contains 162 calories, 37.3 grams carbohydrates, 5.9 grams of dietary fiber, 12.7 grams of starch, 11.7 grams of sugar, and 3.6 grams of protein, but their real value lies in their nutrient profile[1,6,47].

One cup of sweet potato contains 34,590 IU of vitamin A, which is 692 percent of the daily value. They are the highest natural source of vitamin A, which is why they’ve been a healing plant in South American folk medicine for over 5,000 years[4]. In addition, sweet potatoes are a rich source of water-soluble flavonoids that are responsible for their colors, and research suggests that the different flavonoids in the varieties of sweet potatoes have different health benefits.

Sweet potatoes are also a good source of vitamin C, at over half the recommended daily value, as well as vitamin E, vitamin K, thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, choline, betaine, calcium, iron, magnesium, phosphorus, potassium, sodium, zinc, copper, manganese, selenium, and fluoride. All these valuable nutrients contribute to the many health benefits of sweet potatoes[3,5,7,36].

Types of sweet potatoes

Yams and sweet potatoes are not the same thing, though they’re often mislabeled as such. This is important to know, since they offer different health benefits, and some healthy variations on sweet potatoes are labeled as yams. Sweet potatoes are lower in calories and higher in antioxidants, and yams contain a higher level of potassium[12,22,32,37].

The common mislabeled sweet potato varieties are garnet, jewel, and Beauregard yams. All are reddish-orange or brown, a little sweet, and contain more water than a common sweet potato. Most of us are used to eating our bright orange sweet potatoes, but the common sweet potato is actually a light tan color with a yellow interior. In fact, it strongly resembles the color of the Yukon gold potato. Regardless of which you choose, these sweet potatoes offer many of the same nutrients[23,29,33,39,45].

The stokes purple sweet potato is a sweet potato with purple skin and flesh that offers a different flavor and texture. The stokes purple sweet potato is an excellent source of vitamin C, fiber, anthocyanins, and has a low glycemic index. Studies have also shown that purple sweet potatoes can stop fat cell degeneration, which may help reverse various types of brain dysfunction[35,38,40].

Carbohydrate content

Sweet potatoes are high in carbohydrates, but 53 percent of the content is starches. Simple sugars, such as glucose, fructose, sucrose, and maltose, make up the other 32 percent. Sweet potatoes have a medium glycemic index, which means they have a moderate effect on blood sugar[9].

The starches in sweet potatoes are divided into 80 percent rapidly-digested starch, which is quickly broken down and absorbed; 9 percent slowly-digested starch, which breaks down slowly and has less impact on the blood sugar levels; and 12 percent resistant starch, which is an undigested starch that behaves like fiber and feeds friendly gut bacteria[2,8,48].

Sweet potatoes are somewhat high in fiber, with 5.9 grams. The fiber content is divided between soluble fiber, pectin, and insoluble fiber, in the form of cellulose, hemicellulose, and lignin. Soluble fibers increase satiety, which lowers your appetite and controls sugar spikes, and insoluble fibers improve gut health and may prevent certain illnesses[13,25].

Beta-carotene

Beta-carotene is a pigment found in plants that gives them their red-orange color. In the body, beta-carotene is converted to vitamin A, which is a powerful antioxidant that plays a critical role in maintaining healthy vision, skin, and neurological function. Antioxidants protect the body from free radical damage, one of the main causes of premature aging, cell degeneration, and chronic illnesses[14,41].

Beta-carotene helps prevent the formation of UV-induced erythema, or irritation and redness. While it may not be as beneficial as sunscreen, there’s evidence that beta-carotene can provide a natural protection against sunburn by increasing the body’s own defenses against skin damage[27,42].

Beta-carotene also helps delay the progression of age-related macular degeneration, which causes vision changes so severe that blindness can occur. Antioxidants can slow the progression of macular degeneration symptoms because they prevent oxidative stress, which plays a significant role in the degenerations of cells and nerves in the retina.

Vitamin C

Vitamin C is a water-soluble vitamin that works to maintain the health of the body’s connective tissue, as well as acting as a powerful antioxidant. Vitamin C stimulates the production of white blood cells and helps immune cells function properly. The antioxidant properties of vitamin C also protect white blood cells from oxidative damage. Vitamin C can also lessen the length, frequency, and severity of common illnesses[15].

Vitamin C is important for healthy skin and collagen production. Studies have shown that high levels of vitamin C can decrease the appearance of wrinkles and skin dryness. In addition, vitamin C is a powerful antioxidant that reduces the effect of oxidative damage caused by pollution, stress, and poor diet. Free radicals can speed up the aging process, but vitamin C can slow down its effects and improve skin’s appearance[50].

Research suggests that vitamin C is important for maintaining healthy circulation and heart function, and one study found that those with high levels of vitamin C in their blood had a 50 percent decreased risk of stroke. Sweet potatoes contain over half of the daily recommended intake of vitamin C[49].

Vitamin B6

Vitamin B6 is a water-soluble vitamin that influences over 100 different reactions in the body. It is used to make amino acids, which are the building block of proteins and hundreds of cellular functions. Vitamin B6 is also used to make niacin, or vitamin B3, and the amino acid tryptophan, as well as the aiding in the formation of hemoglobin and some neurotransmitters, and regulating blood sugar[11].

Vitamin B6 impacts brain function by controlling homocysteine levels, which damage the neurons of the central nervous system. Vitamin B6 also makes the hormones serotonin and norepinephrine, which regular mood, energy levels, and concentration. Certain behavioral disorders, such as ADHD, are caused by low serotonin levels and consuming vitamin B6 foods may be beneficial for children with these learning and behavioral issues.

The regulation of homocysteine levels is important for heart health as well. In the absence of vitamin B6, homocysteine levels build up and damage the lining of blood vessels. When this happens, plaque can build up on the lining, which can lead to heart attack or stroke. Vitamin B6 also plays a role in managing blood pressure and cholesterol levels, which also contribute to heart disease.

Potassium

Potassium is an essential nutrient that maintains the fluid and electrolyte balance in the body. It is required for normal heart, kidney, brain, and muscular tissue, but many people don’t get enough from their diets. Potassium plays a direct role in maintaining a normal heart rhythm, so a potassium deficiency can have potentially dangerous consequences. In addition, high potassium levels can decrease the risk of stroke and lower high blood pressure, which are risk factors for heart disease[18].

Osteoporosis, an illness that causes bone density loss and weakness. Citrate and bicarbonate, two potassium salts, can improve the health of your bones and ward off osteoporosis by decreasing the urinary excretion of calcium, which helps the bones maintain mineral content.

Low potassium can cause decreased muscle strength, muscle cramps, and soreness. Athlete’s become dehydrated much more easily than less active people, which depletes their potassium. Because of this, potassium is an important nutrient both before and after exercise, and has been shown to decrease cramping and improve muscle strength. One cup of sweet potatoes contains 26 percent of the daily intake of potassium[19].

Manganese

Manganese is an essential trace mineral that plays a role in many chemical processes. It works with other minerals to affect many aspects of your health. In combination with calcium, zinc, and copper, manganese can help reduce bone loss. A deficiency in manganese, though rare in developed countries, poses a risk for bone-related disorders since manganese helps with the formation of bone-regulatory hormones and enzymes involved in bone metabolism. Studies have shown that increasing the intake of manganese, alongside other bone-supporting nutrients, can improve bone mass and naturally treat osteoporosis[30].

Sweet potatoes are a great source of manganese and antioxidants, but manganese is important for the use of arginase, glutamine, synthetase, and manganese superoxide, which work as antioxidants in the body. All of these enzymes fight free radicals, but a deficiency in manganese limits their function. In addition, manganese also forms important enzymes related to bone formation, as well as digestive enzymes that increase nutrient absorption[31].

Lastly, manganese is needed to help with the proper production of the digestive enzymes responsible for gluconeogenesis, which is the conversion of amino acids into sugar and the balance of sugar within the bloodstream. Because of this, manganese is helpful in preventing the excessively-high blood sugar levels common in type 2 diabetes. In addition, the proper function of gluconeogenesis can help improve insulin sensitivity, an important factor in the development of diabetes, as well as other chronic illnesses.

Resistant starch

Resistant starches are indigestible starches that function like soluble fiber. Resistant starch passes through the digestive system until it reaches the colon, where it feeds beneficial bacteria in the gut. Our gut bacteria outnumber our body’s cells 10 to 1, and the number and type of bacteria present have a huge impact on our health.

The digestion of resistant starch by bacteria creates butyrate, a short-chain fatty acid that is the preferred fuel of the cells in the lining of the colon. Because of this, resistant starch can reduce the pH level in the gut, which reduces inflammation and lowers the risk of colorectal cancer, as well as treating ulcerative colitis, Crohn’s disease, constipation, diverticulitis, and diarrhea. Unused butyrate travels to the bloodstream, where it is transported to the other tissues in the body[44].

Resistant starch has been proven to lower blood sugar and improve insulin sensitivity, both of which are markers for type 2 diabetes, metabolic syndrome, obesity, cardiovascular disease, and Alzheimer’s disease. In addition, the satiety effect of resistant starch can cause you to eat fewer calories over the course of the day, which may lead to weight loss[20,43].

Anthocyanins

Anthocyanins are a type of flavonoid that is present in red-orange and blue-violet fruits and vegetables, like sweet potatoes. Studies have shown that anthocyanins, as well as other flavonoids, can inhibit the absorption of cholesterol, as well as increasing HDL (good) cholesterol and lowering LDL (bad) cholesterol. High levels of LDL cholesterol is a major risk factor for heart disease[21].

Antioxidants fight oxidative damage, which can contribute to cognitive decline and memory impairment. Studies have shown that eating anthocyanin-rich foods can delay mental aging by two and a half years, and the higher the intake of anthocyanins, the slower the rate of cognitive decline. In addition, these flavonoids can boost learning and memory in individuals with healthy brains, as well as improving symptoms of depression.

The antioxidant effects of anthocyanins may also prevent cancer. In laboratory studies, anthocyanin intake inhibited the growth of breast cancer cells, blocked tumor cells from forming in prostate cancer, prevented precancerous mouth tumors from becoming malignant, and showed improvement in the symptoms of colon cancer[16]. Overall, anthocyanins can prevent the spread of tumors, which is a significant cause of cancer-related death.

Chlorogenic acid

Chlorogenic acid is the most abundant polyphenol antioxidant in sweet potatoes, which helps regulate the flow of bile from your liver. This prevents bile from building up and becoming stagnant, which may help lower the risk of developing gallstones and gallbladder cancer. In addition, keeping the flow of bile steady can ease the burden on the liver, which decreases the likelihood of developing liver cancer and liver cirrhosis.

Chlorogenic acid is also helpful for weight loss. It slows down the body’s absorption of fat from the diet, as well as increasing the metabolism. In addition, chlorogenic acid can reduce the absorption of carbohydrates from the digestive tract, which lowers blood sugar and insulin spikes. Some studies have shown that chlorogenic acid can reduce body weight, reduce fat stored in the liver, and improve the function of the fat-burning hormone, adiponectin, as well as lowering cholesterol and triglyceride levels[34].

Because chlorogenic acid can regulate blood sugar, lower your metabolism, and help you lose weight, it may also be beneficial for managing type 2 diabetes[10,17]. In addition, diabetics typically have difficulty losing weight or maintaining a healthy weight, and chlorogenic acid’s positive effects on weight loss may help.

Precautions

Though sweet potatoes are generally well-tolerated, they may not be appropriate for some individuals. Sweet potatoes are rich in carbohydrates, which may benefit high-intensity athletic training, but may be too much for someone on a low-carb diet. In addition, sweet potatoes are low in protein, which is an important nutrient for dieting[24].

Sweet potatoes also have high levels of oxalates, which can crystallize if they reach high levels in the body. Oxalates play a role in the formation of calcium-oxalate kidney stones, so individuals with impaired kidney or gallbladder function may have trouble processing and excreting the oxalates in sweet potatoes[26].

Sweet potatoes also contain a type of sugar called mannitol, which can cause stomach pain in individuals with a sensitive stomach. Mannitol can also trigger bloating and diarrhea, so if you experience digestive discomfort whenever you eat sweet potatoes, you may have a sensitivity to mannitol[28,46].

The sati line

Sweet potatoes may be high in carbs, but their remarkable nutrient profile and many health benefits make them a worthwhile addition to your diet. The many varieties of sweet potato offer high antioxidant content, healthy starch, fiber, and many vitamins and minerals that may otherwise be lacking in a typical Western diet.

Starch may be a concern for diabetes and obesity, but the specific type of starch and combination of other beneficial nutrients can actually help with weight loss, blood sugar regulation, insulin sensitivity, and cholesterol levels. In addition, sweet potatoes help maintain healthy digestion, healthy skin, and may prevent certain types of cancers and chronic illnesses.

As part of a balanced diet of whole, unprocessed foods, sweet potatoes can provide a healthy, flavorful alternative to traditional grains and white potatoes, a nutrient-packed source of complex carbohydrates, and a nutritional profile that complements the other vitamins and minerals present in your diet.


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