7 Evidence-Based Health Benefits of Sweet Potatoes
Sweet potatoes are sweet, starchy root vegetables that are grown worldwide. They come in a variety of sizes and colours—including orange, white, and purple—and are rich in vitamins, minerals, antioxidants, and fibre.
Not to be confused with yams, sweet potatoes belong to the morning glory family (Convolvulaceae), whereas yams are tubers related to lilies and grasses. From a nutritional standpoint, sweet potatoes are often hailed as a superfood due to their high concentration of nutrients relative to their calorie content.
Whether mashed, baked, or roasted, adding this root vegetable to your diet can provide significant health advantages. Here are 7 evidence-based health benefits of sweet potatoes.
1. Highly Nutritious and Rich in Vitamins
Sweet potatoes are a powerhouse of nutrition. They are an excellent source of fibre, vitamins, and minerals. A single 200-gram sweet potato (baked with skin) provides:
| Nutrient | Amount | % of Daily Value (DV) |
|---|---|---|
| Calories | 180 | – |
| Carbohydrates | 41.4 g | – |
| Protein | 4 g | – |
| Fat | 0.3 g | – |
| Fibre | 6.6 g | 26% |
| Vitamin A | – | 769% |
| Vitamin C | – | 65% |
| Manganese | – | 50% |
| Vitamin B6 | – | 29% |
| Potassium | – | 27% |
In addition to the nutrients listed above, sweet potatoes are rich in antioxidants that protect your body from free radicals. Free radicals are unstable molecules that can damage DNA and trigger inflammation.
Orange and purple varieties of sweet potatoes are particularly rich in antioxidants, which protect your body from free radicals. Free radical damage has been linked to chronic illnesses like cancer, heart disease, and aging.
For a deeper dive into the nutritional data, you can refer to the USDA FoodData Central database.
2. Promote Gut Health and Digestion
The fibre and antioxidants in sweet potatoes are advantageous for gut health. Sweet potatoes contain two types of fibre: soluble and insoluble.
Your body cannot digest either type. Therefore, fibre stays within your digestive tract and provides a variety of gut-related health benefits.
Certain types of soluble fibre—known as viscous fibres—absorb water and soften your stool. On the other hand, non-viscous, insoluble fibres do not absorb water and add bulk.
Some soluble and insoluble fibres can also be fermented by the bacteria in your colon, creating compounds called short-chain fatty acids (SCFAs) that fuel the cells of your intestinal lining and keep them healthy and strong.
Diets rich in fibre containing 20–33 grams per day have been linked to a lower risk of colon cancer and more regular bowel movements.
Research suggests that the antioxidants in purple sweet potatoes promote the growth of healthy gut bacteria, including specific Bifidobacterium and Lactobacillus species. Greater amounts of these bacteria within the intestines are associated with better gut health and a lower risk of conditions like irritable bowel syndrome (IBS).
For more on how fibre affects the microbiome, see this study from the National Institutes of Health.
3. May Have Cancer-Fighting Properties
Sweet potatoes offer various antioxidants, which may help protect against certain types of cancers. Anthocyanins, a group of antioxidants found in purple sweet potatoes, have been found to slow the growth of certain types of cancer cells in test-tube studies, including those of the bladder, colon, stomach, and breast.
Similarly, mice fed diets rich in purple sweet potatoes showed lower rates of early-stage colon cancer, suggesting that the anthocyanins may have a protective effect.
Orange sweet potatoes are also high in beta-carotene. Though evidence is mixed, some studies suggest that beta-carotene may help reduce the risk of lung and prostate cancers. However, it is important to note that most of these studies are observational or conducted on animals; more human research is needed.
For further reading on anthocyanins and cancer prevention, consult this review in PubMed.
4. Support Healthy Vision
Sweet potatoes are incredibly rich in beta-carotene, the antioxidant responsible for the vegetable's bright orange colour. In fact, one cup (200 grams) of baked orange sweet potato with skin provides more than seven times the amount of beta-carotene that the average adult needs per day.
Beta-carotene is converted to vitamin A in your body and is used to form light-detecting receptors inside your eyes.
Severe vitamin A deficiency is a concern in developing countries and can lead to a special type of blindness known as xerophthalmia. Eating foods rich in beta-carotene can help prevent this condition.
Furthermore, purple sweet potatoes seem to have vision benefits as well. Test-tube studies have found that the anthocyanins provided by sweet potatoes can protect eye cells from damage, which may be significant for overall eye health.
You can read more about the essential role of Vitamin A in vision health at Healthline.
5. May Enhance Brain Function
Consuming purple sweet potatoes may improve brain function. Animal studies have found that the anthocyanins in purple sweet potatoes can protect the brain by reducing inflammation and preventing free radical damage.
Supplementing with anthocyanin-rich sweet potato extract has been shown to improve learning and memory in mice, possibly due to its antioxidant properties.
No studies have been done to test these effects in humans, but generally, diets rich in fruits, vegetables, and antioxidants are associated with a 13% lower risk of mental decline and dementia.
Inflammation is a key driver in cognitive decline, so anti-inflammatory foods are crucial. See this study on brain health and nutrition.
6. Support Your Immune System
Orange-fleshed sweet potatoes are one of the richest natural sources of beta-carotene, a plant-based compound that is converted to vitamin A in your body.
Vitamin A is critical to a healthy immune system, and low blood levels have been linked to reduced immunity. It is key for maintaining healthy mucous membranes, especially in the lining of your gut.
The gut is where your body is exposed to many potential disease-causing pathogens. Therefore, a healthy gut is an essential part of a healthy immune system.
Studies have shown that vitamin A deficiency increases gut inflammation and reduces the ability of your immune system to respond properly to potential threats. Ensuring adequate intake through whole foods is a primary recommendation by the World Health Organization.
7. Help Regulate Blood Sugar Levels
It might seem counterintuitive that a sweet, starchy vegetable could help stabilise blood sugar, but sweet potatoes have a low-to-medium glycaemic index (GI), depending on how they are cooked.
Boiled sweet potatoes have a low GI, meaning they release sugar into the bloodstream slowly, preventing sharp spikes in blood glucose. This makes them a suitable carbohydrate source for people managing type 2 diabetes.
However, baking or roasting sweet potatoes can significantly increase their GI because the heat breaks down the starch into simpler sugars. To maintain a lower GI, boiling is the preferred method.
Furthermore, some research indicates that sweet potatoes may help improve insulin sensitivity. A study published in Diabetes Care suggests that certain compounds in sweet potatoes might help improve blood sugar regulation.
How to Add Them to Your Diet
Sweet potatoes are very easy to add to your diet. They can be enjoyed with or without the skin and can be baked, boiled, roasted, fried, steamed, or pan-cooked.
Their natural sweetness pairs well with many different seasonings, and they can be enjoyed in both savoury and sweet dishes.
Popular preparation methods include:
- Sweet Potato Chips: Peeled, sliced, and baked or fried.
- Sweet Potato Toast: Sliced thinly, toasted, and topped with nut butter or avocado.
- Mashed Sweet Potato: Peeled, boiled, and mashed with milk and seasoning.
- Baked Sweet Potato: Baked whole in the oven until fork-tender.
- Hash: Peeled, diced, and cooked with onion in a pan.
Important Culinary Tip: Since vitamin A is fat-soluble, you should consume sweet potatoes with a source of fat—such as olive oil, butter, or avocado—to dramatically increase the absorption of beta-carotene.
Preparing sweet potatoes with a little fat significantly enhances nutrient uptake. Refer to this study on fat-soluble vitamin absorption.
Potential Downsides
While highly nutritious, sweet potatoes contain oxalates. Oxalates bind to calcium and other minerals. For individuals prone to kidney stones, consuming high amounts of oxalates can be problematic.
If you have a history of calcium-oxalate kidney stones, you may need to moderate your intake or ensure you stay well-hydrated. Boiling sweet potatoes can reduce their oxalate content.
For more information on oxalates and kidney health, visit the National Kidney Foundation.
The Bottom Line
Sweet potatoes are a nutrient-dense root vegetable that comes in a variety of colours. They are high in fibre and antioxidants, which protect your body from free radical damage and promote a healthy gut and brain.
They are also incredibly rich in beta-carotene, which is converted to vitamin A to support good vision and your immune system.
Because they are versatile and can be prepared in many sweet and savoury dishes, sweet potatoes are an exceptional carbohydrate choice for most people. By cooking them appropriately—such as boiling to retain a lower glycaemic index—and pairing them with healthy fats, you can maximise their health benefits.
