Sweet potatoes are one of the most popular vegetables.
However, their leaves are also edible, a fact that may come as a surprise to some. In some regions, sweet potato leaves play a popular part of the cuisine.
Notably, these leaves boast high nutritional value and might offer several potential health benefits.
This article will explore the potential benefits of sweet potato leaves and provides their full nutritional profile.
Sweet potato leaves are a leafy green vegetable that come in various shades of green, which vary depending on their age and the specific sweet potato cultivar. Some are relatively light green, while others sport a deeper, darker green color. These heart-shaped leaves have visible veins running through each leaf and elongated stems.
It’s worth noting that sweet potato leaves and sweet potatoes are both part of the same plant (Ipomoea batatas). However, sweet potato leaves are the above-ground foliage of the plant, whereas sweet potatoes are the underground storage roots (1).
In terms of flavor, sweet potato leaves taste milder compared to many other leafy greens. They are often likened to spinach, but they are much milder in flavor with earthy, subtly sweet tones.
This mild and slightly sweet may appeal to those who are not fans of the stronger, slightly bitter taste associated with leafy greens like kale.
While sweet potatoes may not be as prevalent in the United States and much of the Western world, they are a common vegetable in many Asian and African countries (2). These versatile vegetables feature in a variety of dishes, often featuring in stir-fries and stews. They can also be prepared by sauteing or steaming and being served as a side dish.
Key Point: Sweet potato leaves constitute the above-ground foliage of the sweet potato plant. They possess a mild and earthy taste, and unlike some leafy greens, they are slightly sweet rather than bitter.
Potential Benefits of Sweet Potato Leaves
Based on their nutritional values and the findings of published scientific research, here’s an overview of some potential benefits associated with sweet potato leaves.
1) An Excellent Source of Vitamin K
Sweet potato leaves provide a substantial quantity of vitamin K.
A 64-gram cup of cooked sweet potato leaves provides 69.8 mcg of vitamin A, which is equivalent to 58% of the recommended daily value (3, 4).
Vitamin K is a fat-soluble vitamin that holds significance for bone health. Furthermore, it plays a crucial role in blood clotting and may have potential long-term benefits in terms of reducing the risk of osteoporosis and heart disease (5, 6).
2) May Decrease Oxidative Stress
Oxidative stress refers to a state in which the body is exposed to higher levels of free radicals than the antioxidants available to prevent damage (7).
Free radicals are highly reactive compounds created naturally through metabolism and may also arise from environmental exposures, such as pollution (8).
Elevated levels of oxidative stress have been linked to aging and various chronic diseases (9, 10, 11). Turning our attention to sweet potato leaves, multiple studies have examined their composition of phytochemicals, which are bioactive compounds found in plants that may confer health-protective effects (12, 13, 14, 15).
Several studies have also examined the impact of consuming sweet potato leaves on oxidative stress. In a randomized controlled crossover study, 16 healthy adults consumed 200 grams of sweet potato leaves daily for two weeks (16).
Compared to a low-polyphenol control diet, blood samples revealed that the participants consuming sweet potato leaves exhibited increased levels of plasma polyphenols, significant reductions in markers of DNA damage, and decreased oxidation of LDL cholesterol (LDL-C).
Regarding oxidized LDL-C, a recent systematic review demonstrated that individuals with cardiovascular disease had significantly increased levels (17).
Furthermore, a prior randomized crossover trial published in the Journal of Applied Physiology found favorable effects of sweet potato leaves. In this study involving 15 participants, a diet incorporating sweet potato leaves decreased exercise-induced oxidative stress when compared to the control diet (18).
Key Point: Sweet potato leaves have the potential to mitigate oxidative stress, a condition associated with aging and a heightened risk of various chronic diseases.
3) High Nutrient Density
As previously mentioned, sweet potato leaves are a substantial source of vitamin K. Moreover, they offer a wide range of vitamins and minerals, fiber, and a diverse range of phytochemicals (3, 13).
What’s worth noting is that a 64-gram cup of cooked sweet potato leaves contains merely 22 calories (3).
This underscores the fact that sweet potato leaves offer significant nutritional benefits while containing very few calories.
In other words, they boast a high nutrient density.
4) May Have Benefits For Immune Function
It is prudent to approach this topic with caution, given the limited research available.
Nevertheless, a small randomized controlled crossover study published in the World Journal of Gastroenterology suggested that the consumption of sweet potato leaves may enhance the human immune response (19).
The study spanned six weeks and involved 16 healthy adult participants. When compared to the control group, blood tests revealed that participants consuming a ‘high-polyphenol diet’ (200 grams of sweet potato leaves per day) experienced:
A significant increase in the responsiveness of peripheral blood mononuclear cells.
Elevated lytic activity in ‘natural killer’ cells.
‘Peripheral blood mononuclear cells’ are white blood cells that play a pivotal role in the immune system. Similarly, ‘natural killer’ cells have the ability to induce lysis (cell death) in virus-infected, abnormal, or cancerous cells – an action known as ‘lytic activity.’
Key Point: Sweet potato leaves, with their polyphenol content, may have potential benefits for the immune system.
5) High Polyphenol Content
Many of the potential benefits associated with sweet potato leaves, as observed in studies, can be attributed to their substantial polyphenol content.
Polyphenols are a type of phytochemical thought to have benefits for human health. Notably, high-polyphenol diets consistently correlate with a reduced risk of mortality (20, 21, 22, 23).
Sweet potato leaves encompass a broad range of polyphenols, including (12, 13, 24):
Anthocyanins
Apigenin
Catechins
Kaempferol
Luteolin
Myricetin
Phenolic acids
Quercetin
Key Point: Sweet potato leaves are full of polyphenols, a kind of phytochemical linked to a lower risk of chronic disease and mortality.
The Nutritional Profile of Sweet Potato Leaves
Now that we’ve explored some of their potential benefits, let’s examine the complete nutritional profile of sweet potato leaves.
The tables below display the nutritional values of cooked sweet potato leaves, sourced from the USDA FoodData Central database (3).
Daily values have been computed using this USDA data alongside the FDA’s published daily values (4).
Name
Amount
% Daily Value
Calories
22 kcal
Carbohydrates
4.72 g
1.7%
Fiber
1.22 g
4.3%
Sugars
3.51 g
Fat
0.22 g
0.3%
Saturated
0.04 g
0.2%
Monounsaturated
0.01 g
Polyunsaturated
0.09 g
Omega-3
0.01 g
Omega-6
0.07 g
Protein
1.4 g
2.8%
Cholesterol
0 mg
0%
Water content
57.1 g
Table 1: Nutrition facts for cooked sweet potato leaves per 64-gram cup
As the table shows, sweet potato leaves are primarily a source of carbohydrates.
A cup serving provides a small provision of fiber, has a water content of nearly 90%, and supplies 22 calories.
Vitamins
Vitamin
Amount
% Daily Value
Choline
13.4 mg
2.4%
Folate, DFE
31.4 mcg
7.9%
Vitamin A, RAE
94.1 mcg
10.5%
Vitamin B1 (thiamin)
0.07 mg
5.8%
Vitamin B2 (riboflavin)
0.17 mg
13.1%
Vitamin B3 (niacin)
0.64 mg
4.0%
Vitamin B5 (pantothenic acid)
0.13 mg
2.6%
Vitamin B6 (pyridoxine)
0.10 mg
5.9%
Vitamin B12 (cobalamin)
0 mcg
0%
Vitamin C
0.96 mg
1.1%
Vitamin D
0 mcg
0%
Vitamin E
0.61 mg
4.1%
Vitamin K
69.8 mcg
58.2%
Table 2: Vitamin composition of cooked sweet potato leaves per 64-gram cup
As displayed in the table, a 64-gram cup of cooked sweet potato leaves provides a substantial amount of vitamin K. They also offer more than 5% of the daily value for folate and vitamins A, B2, and B6.
Minerals
Mineral
Amount
% Daily Value
Calcium
21.1 mg
1.6%
Copper
0.02 mg
2.2%
Iron
0.40 mg
2.2%
Magnesium
30.7 mg
7.3%
Manganese
0.15 mg
6.5%
Phosphorus
25.6 mg
2.0%
Potassium
200 mg
4.3%
Selenium
0.58 mcg
1.1%
Sodium
4.48 mg
0.2%
Zinc
0.17 mg
1.5%
Table 3: Mineral composition of cooked sweet potato leaves per 64-gram cup
A cup of cooked sweet potato leaves offer more than 5% of the daily value for magnesium and manganese.
Potential Downsides
As with any food, sweet potato leaves come with some context-dependent potential drawbacks.
One of these is their limited availability, as they are not considered a common vegetable in many Western countries. In this regard, an online search about where to procure them in your local area should suffice.
However, their main potential drawback, for some individuals, is their oxalate content.
High In Oxalate
Oxalate, also known as oxalic acid, is a naturally occurring compound found in some plants.
First, it’s important to note that oxalate is generally not a concern for most healthy people, and our bodies produce it as a waste product, whether we consume oxalates or not (25).
That said, for some individuals, a high intake of oxalate-rich foods can be a risk factor for developing kidney stones (26, 27).
For this reason, some individuals may need to follow a medically-prescribed low-oxalate diet (28, 29).
The oxalate content of sweet potato leaves has been measured at 58.3 mg per 100 grams (30). Since a low-oxalate diet is typically recommended to contain less than 50 mg of oxalate per day, sweet potato leaves may be unsuitable for someone following such a diet (29, 31).
It is also worth noting that an insufficient fluid intake is considered the primary dietary risk factor for developing kidney stones (27, 32).
Common Questions
To provide additional information about sweet potato leaves and address potential queries, here are answers to some frequently asked questions.
Can you eat sweet potato leaves raw?
As with many leafy green vegetables, it is possible to eat sweet potato leaves raw. However, they tend to have a stronger, slightly bitter taste in their raw form compared to when they are cooked. Consequently, most people prefer to cook them before consumption.
Are there different varieties of sweet potato leaves?
There are numerous varieties of sweet potato plants, and as a result, the leaves may slightly vary from one variety to another. That said, any nutritional differences among these varieties are likely to be minor.
How do sweet potato leaves compare to other leafy greens in terms of nutritional value?
Sweet potato leaves offer a decent nutritional profile, providing a range of vitamins and minerals for minimal calories. However, they are not as rich in vitamins and minerals as some other leafy greens. For example, amaranth leaves, beet greens, kale, and spinach offer a greater quantity of micronutrients.
What dishes feature sweet potato leaves?
Sweet potato leaves feature in many different recipes, particularly within Asian and African cuisines. Examples include Chinese ‘stir-fried sweet potato leaves‘ and the Congolese dish ‘Sweet Potato Leaf Stew.’
What is the best way to cook sweet potato leaves?
The ideal cooking method for sweet potato leaves depends on whether you prioritize taste or nutritional value. For taste purposes, many people prefer stir-frying the leaves or adding them to curries, soups, or stews. However, research has indicated that steaming is the “preferred way” to cook sweet potato leaves for maximum preservation of polyphenol content. Frying came second for polyphenol retention, whereas boiling was the least effective method (33).
Final Thoughts
While they may not match the vitamin and mineral content of some other leafy greens, they still offer good nutritional value.
As previously discussed, research suggests they may also provide immune health benefits and help lower oxidative stress.
For those who have never tried them before, sweet potato leaves may be worth sampling.
Michael works as a nutritionist in a community setting and holds a Master's Degree in Clinical Nutrition. He is a Registered Associate Nutritionist with the Association for Nutrition.
