Sweet Potatoes 101: Nutrition Facts and Health Benefits

Sweet potatoes contain important vitamins like beta carotene, vitamin C, and potassium. They also contain fiber and can support a nutrient-rich diet.

Sweet potatoes are rich in beta carotene, a powerful antioxidant that effectively increases blood levels of vitamin A, particularly in children.

These nutritious, high-fiber, and filling vegetables can be enjoyed in various ways, including boiling, baking, steaming, or frying. While they are commonly orange, sweet potatoes also come in other colors like white, red, pink, violet, yellow, and purple.

In some parts of North America, sweet potatoes are mistakenly called yams, but yams are a different species altogether. Interestingly, sweet potatoes are only distantly related to regular potatoes.

This article provides everything you need to know about sweet potatoes.

Nutrition facts

Here are the nutrition facts for 3.5 ounces (100 grams) of raw sweet potatoes:

• Fat: 0.1 grams
• Calories: 86
• Water: 77%
• Protein: 1.6 grams
• Carbs: 20.1 grams
• Sugar: 4.2 grams
• Fiber: 3 grams

Carbs

A medium-sized sweet potato (boiled without the skin) contains 27 grams of carbohydrates, with starches accounting for 53% of the total.

Simple sugars, including glucose, fructose, sucrose, and maltose, make up 32% of the carb content.

Sweet potatoes have a medium to high glycemic index (GI), ranging from 44 to 96, which measures how quickly they raise blood sugar levels after eating.

Due to their relatively high GI, consuming large amounts of sweet potatoes in one meal may not be ideal for people with type 2 diabetes. Boiling sweet potatoes tends to result in lower GI values compared to baking, frying, or roasting.

Starch

Starches are typically divided into three categories based on how easily they are digested. The breakdown of starch types in sweet potatoes is as follows:

• Rapidly digested starch (80%): This type of starch is quickly broken down and absorbed, leading to a higher glycemic index (GI) value.
• Slowly digested starch (9%): This type is broken down more gradually, leading to a more moderate increase in blood sugar levels.
• Resistant starch (11%): This type resists digestion and functions like fiber, nourishing beneficial gut bacteria. The amount of resistant starch can increase slightly when sweet potatoes are cooled after cooking.

Fiber

Cooked sweet potatoes are a good source of fiber, with a medium-sized sweet potato providing 3.8 grams.

This fiber consists of both soluble (15–23%), primarily pectin, and insoluble (77–85%), including cellulose, hemicellulose, and lignin.

Soluble fibers like pectin can promote feelings of fullness, reduce food intake, and help prevent blood sugar spikes by slowing the digestion of sugars and starches.

Insoluble fiber intake is linked to health benefits such as a lower risk of diabetes and improved gut health.

Protein

A medium-sized sweet potato contains 2 grams of protein, making it a relatively low source of protein.

Sweet potatoes contain unique proteins called sporamins, which make up over 80% of their total protein content. These sporamins help the plant heal when it experiences physical damage and have been shown to possess antioxidant properties.

Although sweet potatoes are not high in protein, they are a valuable source of this macronutrient in many developing countries.

Vitamins and minerals

Sweet potatoes are a rich source of beta carotene, vitamin C, and potassium. The key vitamins and minerals found in this vegetable include:

• Pro-vitamin A: Sweet potatoes are high in beta carotene, which the body converts into vitamin A. Just 3.5 ounces (100 grams) of sweet potatoes provide the recommended daily intake of this essential vitamin.
• Vitamin C: This antioxidant may help shorten the duration of the common cold and enhance skin health.
• Potassium: Essential for regulating blood pressure, this mineral may help reduce the risk of heart disease.
• Vitamin B6: This vitamin is crucial for converting food into energy.
• Vitamin B5: Also known as pantothenic acid, this vitamin is present in nearly all foods to some degree.
• Vitamin E: A potent fat-soluble antioxidant that may help protect your body from oxidative damage.

Other plant compounds

Like other whole plant foods, sweet potatoes contain several plant compounds that can influence your health. These include:

• Beta carotene: An antioxidant carotenoid that your body converts into vitamin A. Consuming it with fat can enhance its absorption.
• Chlorogenic acid: The most abundant polyphenol antioxidant found in sweet potatoes.
• Anthocyanins: Purple sweet potatoes are abundant in these compounds, known for their powerful antioxidant properties.

Notably, the antioxidant activity of sweet potatoes increases with the intensity of their flesh color. Varieties with deep hues, like purple, deep orange, and red, have the highest levels of antioxidants.

Cooking sweet potatoes enhances the absorption of vitamin C and certain antioxidants, though levels of some other plant compounds may decrease slightly.

Sweet potatoes vs. regular potatoes

Many people choose sweet potatoes over regular potatoes, considering them the healthier option.

Both species have similar amounts of water, carbs, fat, and protein. However, sweet potatoes typically have a lower glycemic index (GI) and contain higher levels of both sugar and fiber.

While both are good sources of vitamin C and potassium, sweet potatoes provide a significant amount of beta carotene, which the body converts into vitamin A.

Regular potatoes may be more filling, but they also contain glycoalkaloids, compounds that can be harmful in large quantities. Due to their higher fiber and vitamin content, sweet potatoes are often regarded as the healthier choice.

Health benefits of sweet potatoes

Sweet potatoes are associated with multiple benefits.

Prevention of vitamin A deficiency

Vitamin A is crucial for various bodily functions, and deficiency in this essential nutrient is a significant public health concern in many developing countries.

A deficiency can lead to temporary or permanent eye damage, including blindness, and can also weaken the immune system, increasing mortality, particularly among children, pregnant, and lactating women.

Sweet potatoes are an excellent source of beta carotene, which the body efficiently converts into vitamin A. The deeper the yellow or orange hue of a sweet potato, the higher its beta carotene content.

Research shows that orange sweet potatoes are particularly effective at raising vitamin A levels in the body, making them an excellent tool in combating vitamin A deficiency in developing countries.

Improved blood sugar regulation

Imbalances in blood sugar levels and insulin secretion are key characteristics of type 2 diabetes.

Caiapo, a variety of sweet potato with white skin and flesh, may help improve symptoms in individuals with type 2 diabetes. It has been shown to lower fasting blood glucose and LDL (bad) cholesterol levels, while also improving insulin sensitivity.

However, the existing data is not sufficient to recommend sweet potatoes as a treatment for type 2 diabetes, and further human studies are needed.

Reduced oxidative damage and cancer risk

Oxidative cell damage is linked to an increased risk of cancer, a condition marked by uncontrolled cell division.

Diets high in antioxidants, like carotenoids, are associated with a reduced risk of cancers, including stomach, kidney, and breast cancers.

Research suggests that the powerful antioxidants in sweet potatoes may help lower cancer risk, with purple sweet potatoes showing the highest antioxidant activity.

Potential downsides

Sweet potatoes are generally well tolerated by most people.

However, they are relatively high in oxalates, compounds that may increase the risk of kidney stones. Individuals prone to kidney stones may want to moderate their consumption of sweet potatoes.

The bottom line

Sweet potatoes are underground tubers that provide an excellent source of beta carotene, along with various vitamins, minerals, and plant compounds.

This root vegetable may offer several health benefits, including enhanced blood sugar regulation and improved vitamin A levels.

Overall, sweet potatoes are nutritious, affordable, and easy to include in your diet.