Water yam (Dioscorea alata) is a type of tuber that originated in Asia, Africa, and the Caribbean. They are also called English winged yam, greater yam, or purple yam.
In Africa, yams are the third most important tuber crop after cassava and sweet potato.
They are incredibly nutritious, full of fiber, antioxidants, and may benefit your health in many ways.
Read on to discover the nutrition, health benefits, and culinary uses of water yams.
Water yam is rich in vitamins, minerals, fiber, and carbohydrates. 100 grams (g) of fresh edible tubers of water yam will give you :
- Energy:140 Kilocalories
- Moisture content: 65 g
- Carbohydrates: 31 g
- Protein: 2 g
- Fats: 0 g
- Dietary fiber: 3 g
- Vitamin C: 8 milligrams (mg)
- B-carotene: 10 mg
- Vitamin B1: 0.1 mg
- Vitamin B2: 0.04 mg
- Iron:11 mg
- Calcium: 28 mg
- Phosphorus: 28 mg
- Magnesium: 10 mg
Water yams are also excellent sources of copper, manganese, zinc, and potassium – important minerals needed for the proper functioning of cells in your body.
Health benefits of water yam
The possible health benefits of water yams include:
1. Eases menopausal symptoms
Water yams contain loads of antioxidants and nutrients that are good for menopausal women.
One study in 24 postmenopausal women who switched from their staple food of rice to eating 390 g of water yam – two to three times a day – found that after 30 days, their estradiol and estrone levels increased by 27% and 26% respectively. 
During menopause, improving the levels of estradiol and estrone (two female hormones), may relieve menopausal symptoms.
However, further studies are required to determine the exact mechanism of action.
2. Lowers blood sugar level
Water yams are rich in resistant starch – a type of fiber that causes food to be slowly absorbed from your gut because it is not easily digested.
This type of starch is linked to many health benefits, including preventing metabolic disorders like diabetes, cancer, and coronary heart disease.
One animal study found that a modified water yam flour lowered the blood sugar levels in hyperglycemic animals after four weeks. However, further human studies are needed. 
3. May protect heart health
Water yam is rich in minerals (potassium, zinc), dietary fiber, and antioxidants that protect heart health.
Additionally, studies found that processed water yam products may be beneficial in reducing high blood pressure in animal models. 
4. Promotes weight loss
Water yam is rich in resistant starch, a type of fiber that keeps you full for longer periods.
Also, its high water content fills you up quickly – preventing overeating.
It is an ideal food for anyone trying to lose weight, however, remember to always keep your portions small.
5. Lowers cholesterol level
Research has found that women who ate 390 grams of water yams per day for 30 days experienced a 6% decrease in blood cholesterol levels. 
One animal study also found that resistant starch in water yam reduced bad fat – low-density lipoprotein (LDL) in high-fat-fed hamsters. 
A third study found a reduction of total cholesterol, LDL cholesterol, triglyceride, and blood glucose in animals fed with a modified white water yam flour. 
6. Improves digestive health
The high fiber and resistant starch content of water yams may help prevent constipation and other gut-related problems.
One study implies that the resistant starch in water yam (Dioscorea alata) may help increase digestive enzymes that will assist in food break down and increase the number of good bacteria in your gut. 
Other potential health benefits
Water yams may have other health benefits, including:
7. Rich in antioxidants: Vitamin C and B-carotene are powerful antioxidants present in water yam that help fight free radicals that cause cancer and other metabolic disorders.
8. May reduce inflammation: The rich antioxidant content of water yam may help fight chronic inflammatory reactions like diabetes, obesity, and coronary heart disease.
9. May boost fertility: Yam are full of important nutrients that boost fertility. According to an old African myth, women who eat lots of yams are most likely to conceive twin babies.
Culinary uses of water yam (Dioscorea alata)
Water yams are very versatile and easy to prepare.
However, take note that water yam may be different from other species of yam because of their wet-slippery texture.
Here are some easy ways to add them to you diet:
- Yam porridge: Cut yams into small wedges, add palm oil, seasonings, pepper mix, fish or beef, and allow to boil until done.
- Yam chips: Slice yams thinly, add salt, and fry till crispy.
- Purée: Grate water yam, add seasoning, then boil until soft.
- Baked goods. Use yam purée to add moisture to breads, pies, and muffins.
- Mbogiri or Ikokore (local Nigerian dish): Grate water yam and keep it aside. Add palm oil and locust beans in a pot and fry. Then add beef, chicken, or fish and cook till done. Finally add your grated water yam and simmer for 3-5 minutes. Enjoy!
The bottom line
Water yams (Dioscorea alata) are incredibly healthy and nutritious.
They are excellent sources of dietary fiber, potassium, zinc, and antioxidants.
Also, they are linked with various health benefits, and may promote weight loss and boost blood sugar control.
Finally, they are easy to prepare, and a great tuber to include in your diet.
- Baah. F (2009), “Characterization of water yam for existing and potential food products. Upload
- Wu, Wen-Huey et al. “Estrogenic effect of yam ingestion in healthy postmenopausal women.” Journal of the American College of Nutrition vol. 24,4 (2005): 235-43. doi:10.1080/07315724.2005.10719470
- Rosida et al. “Hypoglycemic Effect of Modified Water Yam Flour ( Dioscorea alata ) on Diabetic Wistar Rats ( Rattus norvegicus ).” Journal of Food and Nutrition Research 4 (2016): 20-25.
- Liu, Yuh-Hwa et al. “Effects of different types of yam (Dioscorea alata) products on the blood pressure of spontaneously hypertensive rats.” Bioscience, biotechnology, and biochemistry vol. 73,6 (2009): 1371-6. doi:10.1271/bbb.90022
- Li, Tao et al. “The beneficial effects of purple yam (Dioscorea alata L.) resistant starch on hyperlipidemia in high-fat-fed hamsters.” Food & function vol. 10,5 (2019): 2642-2650. doi:10.1039/c8fo02502a
- Susiloningsih. “Hypocholesterolemic and hypoglycemic effects of autoclaved-cooled water yam ( Dioscorea alata ) on hypercholesterolemia rats.” (2019).