What are sweet potatoes?
Sweet potatoes belong to the Convolvulaceae plant family and are known by the scientific name Ipomoea batatas. The sweet potato is one of the oldest known root vegetables and has been cultivated for 1000s of years, and with good reason! Science has shown that the edible roots of the sweet potato are exceptionally rich in nutrients that can help us stay healthy and ward off disease.
Although they may share the same common name, the sweet potato is nothing more than a distant relation of the regular potato and pound for pound, they pack a considerably heavier nutritional punch. The sweet potato is thought to have originated in central or south America but over the centuries it has been introduced and domesticated in many tropical or sub-tropical countries like China, Indonesia, Vietnam and many African nations like Nigeria, Tanzania, and Uganda.
If you are looking for a healthy food staple, the sweet potato is a delicious and versatile option. It is a nutrient-rich superfood that is jam-packed with macronutrients, micronutrients, phytonutrients and, antioxidants.
Sweet potatoes are available in hundreds of different varieties – each with slightly different colors, flavors and nutritional profiles. They can be white, cream, tan, orange, rose and purple depending on their variety.
Archeologists have carbon dated the sweet potato at about 8000 – 10000 years old from dried roots found in a Chilca Canyon cave in Peru.
The Paleo-Indians would have been the very first people to eat the earliest form of sweet potato. Although the sweet potato that the Paleo-Indians gathered probably wasn’t quite as delicious as the ones we buy at the supermarket today, they would still have been an excellent source of nutrition.Italian explorer Christopher Columbus stumbled upon America in the 15th century on his quest to find gold and treasure.
He may not have found the riches he was looking for but he did come across another little gem – the sweet potato.Columbus returned to Spain in due course and introduced the sweet potato to European cuisine at the end of the 15th century.
Sweet Potato Health Benefits
Even as far back as the 16th-century academics were speculating on the health benefits of the sweet potato. English botanist John Gerard commented in his “Generall Historie of Plantes” book (published in 1597) that the sweet potato “comforts, strengthens, and nourishes the body,” as well as “procuring bodily lust.”
Modern science has since removed much of the guesswork and speculation and given us a much deeper understanding of nutrition and how specific foods affect the body.
Sweet potatoes are a rich source of nutrients that have antioxidant activity. (Read More)
Antioxidant properties of sweet potatoes
Antioxidants are known to protect and extend the life of cells in the human body. A diet that is rich in antioxidants can help promote excellent health by reducing the effects of aging and reducing the risk of cancer, heart disease and, neurological diseases. Sweet potatoes are exceptionally high in vitamin A and beta-carotene which are known to significantly reduce the risk of certain cancers. In addition, it is also known that people who eat foods that are loaded with beta-carotene are less likely to suffer from heart disease. Recent research has highlighted the powerful antioxidant activities of two unique metallothionein proteins (MT-I and MT-II) that are found in sweet potatoes.
Anti-inflammatory properties of sweet potatoes.
The science behind anti-inflammatory diets suggests that phytonutrients in sweet potatoes can help protect the body from the host of diseases that are linked to inflammation. Many diseases like cancer, heart disease, diabetes, arthritis, Crohn’s disease and Alzheimer’s are all being associated with chronic inflammation. A healthy diet plays an important part in the prevention and reversal of inflammation.
Vitamin A is important for maintaining the health of the tissue lining the lungs. Research has also shown that there are links between vitamin A, smoking and lung health. Benzo(a)pyrene, a group 1 carcinogen which is found in cigarette smoke is known to decrease vitamin A levels and cause emphysema. Studies have shown that smokers who eat a diet rich in vitamin A have less chance of developing smoking-related lung diseases. Eating sweet potatoes as part of a healthy diet is a great way to maintain optimum vitamin A levels and keep your lungs functioning properly. Research suggests that a diet high in vitamin A is doubly important for people who smoke regularly.
Despite their sweet taste, sweet potatoes are actually classed as diabetic-friendly because of their ability to stabilize blood sugar levels and lower resistance to insulin. Sweet potatoes are high in dietary fiber which slows down digestion and the release of sugar into the bloodstream. Research that tested and compared the effects of white-skinned sweet potatoes and troglitazone (an anti-diabetic drug) on insulin resistance found that sweet potatoes displayed remarkable results that were comparable to the anti-diabetic drug.
Sweet potatoes are rich in vitamin A which is strongly related to eye health. Vitamin A is sometimes referred to as the vision vitamin because of its importance to the health of the light-sensitive tissue at the rear of the eye. A diet rich in vitamin A may also reduce the risk of age-related eye disorders like AMD cataracts.
Sweet potatoes represent a good source of fiber for helping to maintain a healthy digestive system. Fiber helps slow down the passage of food through the digestive tract preventing you from feeling hungry too soon and controlling blood glucose and cholesterol levels. In addition, a diet that is loaded with fiber helps maintain healthy bowel movements and reduce the risk of certain diseases like cancer, heart disease, diabetes.
Even as far back as the 16th-century academics were speculating on the health benefits of the sweet potato. English botanist John Gerard commented in his “Generall Historie of Plantes” book (published in 1597) that the sweet potato “comforts, strengthens, and nourishes the body,” as well as “procuring bodily lust.” Modern science has since removed much of the guesswork and speculation and given us a much deeper understanding of nutrition and how specific foods affect the body.
There is more vitamin A in one sweet potato than in 23 cups of broccoli.
The sweet potato has so many positives in its favor, it would be a mistake not to include it in your balanced diet. The sweet potato is often referred to as a superfood due to the high density of nutrients contained in its skin and flesh. Highlights from the sweet potato nutritional profile include:
The sweet potato is one of the best natural sources of vitamin A. Just one medium/large sweet potato contains enough vitamin A to provide over 100% of a persons recommended dietary allowance. Vitamin A is an important nutrient that is essential for the following organ health and body functions. Because the vitamin A sourced from fruit and vegetables needs to be converted by the body to a chemical similar to retinol, the recommended dietary allowance is measured in micrograms RAE (retinol activity equivalents). One medium sized 114g sweet potato contains around 1096 micrograms (mcg) RAE of vitamin A.
Vitamin A is known as the vision vitamin because an adequate supply is important for ensuring the health of the eyes. People who regularly eat foods that contain high levels of vitamin A are also less likely to suffer from eye disorders like age-related macular degeneration (AMD) and cataracts.
Vitamin A helps keep the skin smooth and supple. In addition, it also keeps the mucous membranes that line the mouth, nose, throat, vagina, rectum, and urethra well lubricated. Healthy and plentiful mucous is important for keeping the underlying skin moist and preventing bacteria from entering deep tissue.
Bones and teeth
In order to keep bones strong and healthy, the human body is constantly replacing the old bone with new by reabsorbing minerals and calcium into the bloodstream and then synthesizing fresh bone tissue. Vitamin A is vital for this process. Vitamin A is also important in the formation of ameloblasts for healthy teeth enamel and odontoblasts for healthy teeth dentin.
Vitamin A recommended dietary allowance.
- Men – 900 micrograms(mcg)/day
- Women – 700 micrograms(mcg)/day
- Pregnant Women – 770 micrograms(mcg)/day
- Breastfeeding Women – 1300 micrograms(mcg)/day*
Sweet potatoes are a very good source of vitamin C. One medium-sized sweet potato provides 22.3 mg of vitamin C which would provide about 25% of a person’s recommended daily allowance. Vitamin C is an important nutrient that is essential for the following organ health and body functions:
There is some compelling evidence to suggest that a higher level of vitamin C intake may play a role in reducing the risk of cardiovascular disease.
Research has shown that a higher intake of vitamin C may reduce the signs of aging by lessening the appearance of wrinkles.
Cells of the immune system require vitamin C to function efficiently. A higher intake of vitamin C can help to boost resistance to infection whilst a deficiency can weaken and deplete the immune system’s effectiveness.
VITAMIN C RECOMMENDED DIETARY ALLOWANCE.
- Men – 90 milligrams(mg)/day*
- Women – 75 milligrams(mg)/day*
- Pregnant Women – 85 milligrams(mg)/day*
- Breastfeeding Women – 120 milligrams(mg)/day*
Sweet potatoes are a very good source of the mineral manganese (Mn). There are no Recommended Daily Allowance (RDA) guidelines for manganese but for general advice, the Adequate Intake (AI) levels can be used. One medium-sized sweet potato contains about 0.6 mg of manganese which provides about 25% of a person’s Adequate Intake amount. Manganese is considered to be an essential mineral that important for health and wellbeing.
Manganese is an important trace mineral in the mineralization and formation of bone tissue, bone cartilage, and bone collagen.
Manganese is important for improving fertility and supporting a healthy reproduction system.
Manganese is beneficial for healthy brain and nervous system functioning.
MANGANESE ADEQUATE INTAKE (AI) LEVELS
- Men – 2.3 milligrams(mg)/day
- Women – 1.8 milligrams(mg)/day
- Pregnant Women – 2 milligrams(mg)/day
- Breastfeeding Women – 2.6 milligrams(mg)/day
Sweet potatoes are a good source of copper (Cu). The Recommended Daily Allowance (RDA) for copper is 0.9 Mg One medium-sized sweet potato contains about 0.2 mg of manganese which provides about 22% of a person’s Recommended Daily Allowance (RDA). Copper is important for strong bones, a healthy immune system, and child development.
Copper promotes the growth of strong bones. Inadequate copper levels in the body can lead to weak and fragile bones.
Copper is beneficial for healthy brain and nervous system functioning.
Copper is an antioxidant that prevents free radicals from damaging body tissue.
Copper recommended daily allowance
- Men – 0.9 milligrams(mg)/day
- Women – 0.9 milligrams(mg)/day
- Pregnant Women – 1 milligrams(mg)/day
- Breastfeeding Women – 1.3 milligrams(mg)/day
Sweet potatoes are a good source of vitamin B6. One medium-sized sweet potato contains about 0.3 mg of vitamin B6 which provides about 23% of a person’s Recommended Daily Allowance (RDA). Vitamin B6 is important for many body processes including digestion, boosting energy and brain and nervous system health.
Vitamin B6 helps convert food into to energy to fuel the body. Low vitamin b6 levels can result in dips and crashes in energy levels.
Vitamin B6 helps the body produce serotonin. Low levels of serotonin are associated with depression.
Vitamin B6 may reduce the risk of age-related vision loss by keeping the lining of the blood vessels in the eyes healthy.
Vitamin B6 recommended daily allowance
- Men (19-50 years) – 1.3 milligrammes (mg)/day
- Men (51+ years) – 1.7 milligrammes (mg)/day
- Women (19-50 years) – 1.3 milligrams (mg)/day
- Women (50+ years) – 1.5 milligrammes (mg)/day
- Pregnant Women – 1.9 milligrams (mg)/day
- Breastfeeding Women – 2 milligrams (mg)/day
Potassium is a key mineral that is vital for a number of important physiological functions. Maintaining optimum levels of potassium in the blood and cells is crucial for balancing blood pressure, regulating nerve and muscle action, avoiding calcium loss and promoting strong bones. Adding sweet potatoes to your diet is a good way to help maintain potassium levels – one medium-sized sweet potato contains about 542 mg of potassium which equates to about 12% of an average adult’s adequate intake level.
There is a growing body of research-based evidence to suggest that potassium can play an important role in lowering a person’s risk of having a stroke.
A diet that is rich in potassium can help to control blood pressure levels and prevent heart disease, stroke, dementia and kidney failure.
Potassium is necessary for healthy muscle contraction (this includes the heart). Low potassium levels can cause fatigue, poor coordination, and heart palpitations.
Potassium adequate intake level (AI)
- Men (19-50 years) – 4,700 milligrammes (mg)/day
- Women (19-50 years) – 4,700 milligrams (mg)/day
- Pregnant Women – 4,700 milligrams (mg)/day
- Breastfeeding Women – 5,100 milligrams (mg)/day
Frequently Asked Questions
What is the best way to select sweet potatoes?
When selecting sweet potatoes, always look for ones that are firm to the touch and free from soft spots, cracks and bruises. As with most vegetables it is preferable to choose organically grown produce that is free from pesticides and insecticides.
When are sweet potatoes in season?
Although sweet potatoes are always available in groceries and supermarkets, their true peak season is November and December. During these months their nutritional value and taste are at their highest.
Are sweet potatoes just sweeter tasting potatoes?
Sweet potatoes are a completely different vegetable compared to normal potatoes. The sweet potato comes from the wonderfully named “morning glory” family of plants whereas the common potato belongs to the “nightshade” group.
Sweet potatoes have a number of nutritional benefits over normal potatoes.
How do you store sweet potatoes?
Sweet potatoes should be stored in a cool, dry, dark place like a cellar or a well-ventilated cupboard. They should never be kept above 60ºF or in sunlight as this will encourage them to sprout. It is also important not to keep raw sweet potatoes in the refrigerator as the moisture will alter their taste. If they are kept in suitable conditions, sweet potatoes will stay fresh for about 4 weeks.
Is is Ok to eat sweet potato skins?
Yes, sweet potato skins are both edible and highly nutritious. If you eat both the sweet potato skin and flesh you will gain the maximum health benefit from your meal. If possible alway buy organic produce because mass produced vegetables may contain pesticide residue and waxes on the skins. To prepare organically grown sweet potatoes, just rinse them under the colder water tap to remove dirt and grime. If you are going to eat mass produced sweet potatoes, it is best to wash them with a fruit and vegetable wash to remove as much of the farm chemicals and waxes as possible.