If you are a lover of tubers, you will surely be interested in learning a little more about yams. Here we explain what yams are, their types, characteristics, properties, healthy benefits, the best way to take advantage of all their nutrients … and other curious facts about this delicious root vegetable.
What is a yam?
Yams are starchy tubers of African origin, botanically belonging to the genus Dioscorea. The word yam comes from the African word “nyami,” which means “to eat.” Although yams are consumed almost all over the world today, their cultivation is located in Africa and Asia since prehistoric times. Today it is a staple food in South America, Africa, the West Indies, and the Pacific Islands.
Fun facts and features
- In 8,000 BC, more than 10,000 years ago, yams were already cultivated in parts of Asia.
- This tuber is considered an essential food crop, especially in Africa. Some of its varieties can be stored for months without refrigeration.
- The water yam, commonly grown in Southeast Asia, grows 8 feet long and can weigh over 100 pounds.
- There are about 600 species of yams, of which only 25 are grown for food or medicinal purposes.
- It is a very nutritious food that provides carbohydrates, proteins, vitamins (A, C), essential minerals, phosphorus, and potassium.
- Yams should be stored in a dry, dark, and well-ventilated place, and they should not be refrigerated. If stored correctly, they can last from 1 to 6 months, depending on the variety.
Types of yams
- White yam (Dioscorea rotundata): White yam is an edible yam widely cultivated in West Africa. It is characterized by its thick and large leaves (about 20 cm long) and the tiny spines that emerge from them. This species was introduced to South America from Africa through the slave trade.
- Yellow yam (Dioscorea cayenensis): This yam species is also native to Africa, although cultivated in America. Along with the white yam, this is one of the most cultivated yams in the world. Until now, it had been considered that white and yellow yams are two different types of yams (separate species). However, currently, most taxonomists consider them as the same species.
- Water yam (Dioscorea alata): These tubers, also known as purple yam, winged yam, ube, or ubi, are usually purple in color, although they can occasionally be white. Many people confuse this type of yam with taro (taro), as both tubers have similar appearances and tastes. Although not grown as much as the African yam (white and yellow), the water yam has the widest cultivation distribution, harvested in Asia, the Pacific Islands, Africa, and the West Indies.
- Chinese yam (Dioscorea) . The Chinese yam is a type of medicinal yam originating in the valleys and mountains of China, where it is also cultivated as a staple food, especially in the winter months. Chinese yam is a good remedy for the stomach in traditional medicine due to its allantoin, a substance with healing properties that accelerates the healing process of wounds in the gastric mucosa. It is widely used to relieve the symptoms of gastritis, ulcers, and stomach pain. Please click here to find out in detail the Chinese yam.
- Wild or Wild Yam (Dioscorea villosa): Wild yam grows wild mostly in North America, near lakes, swamps, rainforests, and hillsides. This species is not consumed very frequently due to its bitter taste; however, it is highly promoted as a “natural alternative” to estrogen therapy in women who suffer from vaginal dryness, premenstrual syndrome, severe menstrual cramps, and weak bones (osteoporosis). Wild yam is said to act as a stimulant of energy and sexual desire in both men and women.
- Bitter yam (Dioscorea dumetorum): This type of yam is native to West Africa. Its cultivation is not generalized because it is a species that includes poisonous varieties.
Nutritional properties of yams
Although yam contains starch, it is considered a low-glycemic food due to its contribution to complex carbohydrates and dietary fiber. It is an excellent source of vitamin C (27% of the recommended daily value), potassium, manganese, copper, calcium, iron, phosphorus, and B vitamins (thiamine, riboflavin, folic acid, pantothenic acid, and niacin). It also provides antioxidants, such as vitamin A, which is still a significant value although not as abundant as other vegetables ( sweet potatoes ).
Yam Nutrition Facts (3.5 ounces, or 100 grams, of raw yams):
- Calories: 118
- Fat: 0 g
- Cholesterol: 0 mg
- Sodio: 9 mg
- Carbohydrates: 28 g (9%)
- Dietary fiber: 4 g (16%)
- Azúcar: 0 g
- Protein: 2 g
- Vitamin A: 3%
- Vitamin C: 28%
- Calcium: 2%
- Iron: 3%
What is yam for? Benefits and uses
- It helps to cure skin diseases and respiratory problems. Yam has been used in traditional medicine in many countries, for example, China, Korea, and Japan. Its allantoin content stimulates cell proliferation and accelerates the healing process when applied topically on ulcers, boils, and other skin conditions. Its decoction also helps to stimulate and relieve bronchial irritation, cough, and other respiratory problems.1
- Helps prevent heart disease. Yams are an excellent source of vitamin B6, a nutrient the body needs to break down a substance called homocysteine. Homocysteine can damage the walls of blood vessels and cause heart attacks in certain cases.2 On the other hand, yam contains potassium, an important component in the production of body and cellular fluids, which also controls heart rate and blood pressure by counteracting the hypertensive effects of sodium.3 Some research claims that dioscorin, a protein found in yams, may benefit people with hypertension.
- Supports the female endocrine system. Yam is particularly useful for menopausal women, as it contains an enzyme capable of mimicking hormone replacement therapy in women who have reached menopause. This tuber has traditionally been used to treat breastfeeding problems, nausea during pregnancy, symptoms of premenstrual syndrome (PMS), muscle cramps, and hormone imbalance.4
- It is rich in antioxidants. Yams contain healthy antioxidants, such as beta-carotene and vitamin C, compounds that help the body undo the damage caused by free radicals (associated with the formation of cancer cells).
- It has a low glycemic index. Yams are mainly composed of complex carbohydrates and dietary fiber, which help keep blood glucose levels balanced. It is a highly recommended food for people with diabetes.
- It helps digestion and improves bowel habits. The dietary fiber present in yams helps prevent constipation. At the same time, its potassium content improves digestion and stimulates the contraction of smooth muscle in the stomach, helping to have proper bowel habits.5
- It is a healthy source of energy. Being a source of complex carbohydrates and fiber, yams are a good option to keep energy levels stable over time. It is also rich in manganese, a mineral that favors the metabolism of carbohydrates and is involved in energy production.
- It helps in the metabolic functions of the body. Carotenes are essential for metabolizing vitamin A. In turn, vitamin A improves vision and maintains the health of the mucous membranes and skin. Vitamin C boosts collagen production, fights to age, improves immunity, accelerates wound healing, and supports bone growth.
- Promotes hair health. Anthocyanins, beta-carotene, and vitamin A present in yams are beneficial for cell growth, including hair growth.
How to consume yams?
Yams can be consumed in many ways, whether boiled, steamed, baked or fried. People often puree-cooked yam, add yam pieces to soups, or use it to accompany some roast meats. It can also be used in the preparation of cakes, muffins, and bread.
In some countries, yam is available in supplement form (capsules), as its use can balance hormones and improve women’s reproductive health.
In general, it is recommended to consume roasted or steamed yams instead of eating them boiled since this cooking causes the dissolution and loss of several water-soluble nutrients.
Yam Cream (mote) recipe:
Frequent questions
Does yam make you fat?
Yams are starchy foods and relatively high in calories, so eating them in excess can weight gain. That said, these tubers are also rich in dietary fiber and complex carbohydrates that regulate the rate at which sugars are released and absorbed into the body. This can make you feel full and energetic for longer, so if you eat yams in moderation and substitute for other less healthy carbohydrates, it can be a great healthy option for overweight people or want to lose weight.
How to store yams?
Yams should be stored in a cool, dry, dark, well-ventilated place but should not be refrigerated. Depending on the species, they can be kept fresh for 1 to 6 months if properly stored.
What is the origin of the yam?
It is said that more than 10,000 years ago, yams began to be cultivated in both Africa and Asia. People grew this tuber rather than digging up the wild yams. Sometime later, its cultivation gained strength in some areas of the New World.
For hundreds of years, yams were the most important food in many parts of Africa and the Pacific islands. This is demonstrated by the current existence of various traditions associated with yam, including ceremonies and festivals.
What is the yam plant like?
The yam plant is a herbaceous vine that is 5 to 30 inches long and branches occasionally. Its slender stems have the ability to curl around vegetation and possible adjacent fences, ascending upwards and to the sides.
The stems are light green, pale yellow, reddish-green, or dark red. At maturity, the individual leaves of this plant are broad and smooth, with a medium green and wine red upper surface, while the lower surface is pale green.
How is yam grown?
After harvest, yams should have a “dormant” period of approximately three to four months, during the dry season, so that they can produce suitable seeds. After this period, the tubers should be cut crosswise into three pieces before planting.
Yams thrive in loose, well-drained clay soil. Tuber pieces should be planted 2 inches deep, leaving 18 inches apart between each planting.
About a month after they are planted, the threads emerge. Stakes should be placed between the plants at this time, creating an A-shaped structure for the two plants to climb and join. The vines of the yam plant need support to produce a good yield.
Considering that yams are a perennial crop, they can be planted and then harvested whenever desired (1, 2, or 3 years later)
What does yam taste like?
Yam is a tuber whose flavor is similar to a mixture between potato and taro (taro) but less intense.
What other names does it have?
Other common names for yams are mapuey, wanka, ube, and Ubi. More than 600 species of yams are included in the genus Discorea; the most common scientific names are Dioscorea alata and Dioscorea esculenta.