Dioscorea alata is a species of yam commonly referred to as purple yam, ube, violet yam, or water yam.
This tuberous root vegetable originates from Southeast Asia and is often confused with taro root. An indigenous staple of the Philippines, it’s now cultivated and enjoyed worldwide.
Purple yams have greyish-brown skins and purple flesh, and their texture becomes soft like a potato when cooked.
They have a sweet, nutty flavor and are used in a variety of dishes ranging from sweet to savory.
What’s more, they are loaded with vitamins, minerals, and antioxidants, all of which may benefit your health.
Here are 7 surprising health benefits of purple yam.
The purple yam (ube) is a starchy root vegetable that’s a great source of carbs, potassium, and vitamin C.
One cup (100 grams) of cooked ube provides the following (1):
- Calories: 140
- Carbs: 27 grams
- Protein: 1 gram
- Fat: 0.1 grams
- Fiber: 4 grams
- Sodium: 0.83% of the Daily Value (DV)
- Potassium: 13.5% of the DV
- Calcium: 2% of the DV
- Iron: 4% of the DV
- Vitamin C: 40% of the DV
- Vitamin A: 4% of the DV
In addition, they are rich in powerful plant compounds and antioxidants, including anthocyanins, which give them their vibrant hue.
What’s more, purple yams are rich in vitamin C, which helps keep your cells healthy, boosts iron absorption, and protects your DNA from damage (5).
Summary Purple yams are starchy root vegetables that are rich in carbs, potassium, vitamin C, and phytonutrients, all of which are important for maintaining good health.
Purple yams are rich in antioxidants, including anthocyanins and vitamin C.
Antioxidants help protect your cells from damage caused by harmful molecules called free radicals (
Free radical damage is linked to many chronic conditions, such as cancer, heart disease, diabetes, and neurodegenerative disorders (
Purple yams are a great source of vitamin C, which acts as a potent antioxidant in your body.
The anthocyanins in purple yams are also a type of polyphenol antioxidant.
Promising research suggests that two anthocyanins in purple yams — cyanidin and peonidin — may reduce the growth of certain types of cancers, including:
- Colon cancer. One study showed up to a 45% reduction in tumors in animals treated with dietary cyanidin, while another test-tube study found that it slowed the growth of human cancer cells (
- Lung cancer. A test-tube study observed that peonidin slowed the growth of lung cancer cells (
- Prostate cancer. Another test-tube study noted that cyanidin reduced the number of human prostate cancer cells (
That said, these studies used concentrated amounts of cyanidin and peonidin. Thus, it’s unlikely that you would reap the same benefits from eating whole purple yams.
Summary Purple yams are a great source of anthocyanins and vitamin C, both of which are powerful antioxidants. They have been shown to protect against cell damage and cancer.
The flavonoids in purple yams have been shown to help lower blood sugar in those with type 2 diabetes.
Obesity and inflammation caused by oxidative stress increase your risk of insulin resistance, poor blood sugar control, and type 2 diabetes (
Insulin resistance is when your cells don’t respond properly to the hormone insulin, which is responsible for maintaining your blood sugar control.
One test-tube study observed that flavonoid-rich purple yam extracts reduced oxidative stress and insulin resistance by protecting insulin-producing cells in the liver (19).
In addition, a study in 20 rats found that administering them higher amounts of purple yam extract lowered appetite, encouraged weight loss, and improved blood sugar control (20).
Finally, another study reported that a purple yam supplement reduced the rate of blood sugar absorption in rats with elevated levels, resulting in improved blood sugar control (21).
This is likely due in part to purple yams’ low glycemic index (GI). The GI, which ranges from 0–100, is a measure of how fast sugars are absorbed into your bloodstream.
Summary The flavonoids in purple yams may help promote blood sugar control in people with type 2 diabetes. Also, purple yams have a low glycemic index, which can help prevent blood sugar spikes.
Purple yams may have blood-pressure-lowering effects. Researchers believe this is likely due to their impressive antioxidant content (25).
A test-tube study found that purple yams contain antioxidants that may help lower blood pressure in a way similar to that of common blood-pressure-lowering medications called angiotensin-converting-enzyme inhibitors (ACE inhibitors) (26).
Another test-tube study showed that the antioxidants in purple yams could prevent the conversion of angiotensin 1 to angiotensin 2, a compound responsible for elevated blood pressure (26).
While these results are promising, they were obtained in a lab. More human research is needed before concluding whether eating purple yams can lower your blood pressure.
Summary Lab research has demonstrated the impressive blood-pressure-lowering effects of antioxidant-rich purple yam extracts. Still, more human studies are needed.
Asthma is a chronic inflammatory disease of the airways.
One review of 40 studies found that the occurrence of asthma in adults was associated with low vitamin A intake. In fact, those with asthma were only meeting about 50% of the daily recommended intake of vitamin A, on average (29).
In addition, the incidence of asthma increased by 12% in those who had low dietary vitamin C intake.
Purple yams are a good source of antioxidants and vitamins A and C, helping you reach your daily intake levels for these vitamins.
Summary Antioxidants like vitamins A and C in purple yams may help reduce the risk and symptoms of asthma.
Purple yams may help improve your gut health.
They are full of complex carbs and a good source of resistant starch, a type of carb that is resistant to digestion.
One test-tube study showed that resistant starch from purple yams increased the number of Bifidobacteria, a type of beneficial gut bacteria, in a simulated large bowel environment (
They may even help reduce your risk of certain conditions, such as colorectal cancer, inflammatory bowel disease (IBD), and irritable bowel syndrome (IBS). They also produce healthy fatty acids and B vitamins (
Furthermore, one study in mice found that purple yams had anti-inflammatory effects and decreased symptoms of colitis (
However, more research is needed to know if eating whole purple yams has anti-inflammatory effects in humans with colitis.
Summary The resistant starch in yams helps increase the growth of Bifidobacteria, which are healthy bacteria that play a vital role in maintaining your gut health.
Purple yams have a wide range of culinary uses.
These versatile tubers can be boiled, mashed, fried, or baked. They are often used in a variety of dishes in place of other starchy vegetables, including:
In the Philippines, purple yams are made into a flour called ube, which is used in many desserts.
Furthermore, ube can be processed into a powder that can be used to make vibrantly colored foods, including rice, candy, cakes, desserts, and jams.
Summary Purple yams can be converted into various forms, making them one of the most versatile vegetables in the world.
Taro root (Colocasia esculenta) is a root vegetable native to Southeast Asia.
Often called the potato of the tropics, it varies in color from white to grey to lavender and has a mildly sweet taste.
Purple yams and taro root look similar, hence the confusion between the two. Nonetheless, when stripped of their skins, they are different colors.
Taro is grown from the tropical taro plant and is not one of the nearly 600 types of yams.
Summary Taro root grows from the taro plant, and unlike purple yams, they are not a species of yam.
Purple yams are an incredibly nutritious starchy root vegetable.
Their powerful antioxidants may help reduce your blood pressure and blood sugar levels.
They are tasty and versatile with a vibrant color, making them an exciting ingredient that can be used in a variety of sweet and savory dishes.