How bitter yam helps with diabetes, fertility, others

Bitter yam, also called ona in Igbo and esuru in Yoruba, is a delicacy that has a lot of medicinal values, according to experts.

It is an African species of yam with a fleshy, potato-like root (tuber).

A study by MediClinic revealed that bitter yam could be used to treat certain ailments like diabetes, rheumatoid arthritis (RA), stomach pain (colic), menstrual disorders, and schistosomiasis. Schistosomiasis is a disease caused by parasitic worms.

Bitter yam also contains important minerals such as iron, magnesium, phosphorus, calcium, and zinc, even at a very high level when stored for some time, and therefore has some useful applications in the food and pharmaceutical industries.

A nutritionist and lecturer at Emirate College of Health and Technology, Saadatu Sulaiman, said this variety of yam has been found to treat diabetes by helping in lowering blood sugar level among other benefits.

She said there are wild types of bitter yam which are likely to contain poisons, adding that the one raised by farmers generally do not have toxins because they are cultivated selectively.

She said the yellow variety of bitter yam is the most preferred of the edible varieties, and that the edible varieties cannot be pounded, unlike white yam (dioscorea, rotundata).

“The toxic varieties are not edible but they are commonly used for pharmaceutical or medicinal purposes by African and Asian people. Research shows that it contains dihydrodiscorine isoclines, a heart stimulant and dioscorcoretine, a hypoglycemic agent,” she said.

Also, a nutritional health coach, Dr. Nnedinma Iwueke, said other common names of the yam are threeleaved yam, bitter yam and cluster yam, adding that there are four common varieties of bitter yam; two are edible, while the other two are toxic.

“Yellowish-white is toxic to animals alone and the white is toxic to both animals and man. Bitter yam, like any other yam tuber, is a very good source of energy and carbohydrate when consumed. It is also used in the production of local beer from the detoxified variety. The yellow variety of bitter yam is the most preferred of the edible varieties.”

She said bitter yam has been found to contain secondary metabolites such as saponins, tannins, flavonoids which support various health benefits associated with it.

The health benefits include:

- It contains saponins, responsible for the lowering of blood cholesterol

- It has been shown to contain dihydrodiscorine isoclines, a heart stimulant and dioscorcoretine.

- It has been reported that the use of Discorea dumentorum tuber by Nigerian herbalists for the treatments of clinical diabetes.

- Bitter yam contains most of the important minerals such as iron, magnesium, phosphorus, calcium and zinc, useful in the food and pharmaceutical industries.

- Bitter yam can be used in the treatment of rheumatoid arthritis (RA), stomach pain (colic), menstrual disorders and schistosomiasis etc.

The nutritional health coach said bitter yam has also long been proven to play active roles in the treatment of diabetes in traditional medicine due to its hypoglycemic effect.

Some values of bitter yam as a fertility booster identified by experts are:

Bitter yams contain a form of natural progesterone (dioscin). During the reproductive cycle, the body begins to produce increased amounts of progesterone in the luteal phase immediately following ovulation. Progesterone helps the lining of the endometrium grow and thicken. If an egg is fertilized after ovulation, the thickened endometrial lining creates a healthy environment for the growth of a fetus.

- The phytoestrogens and progesterone-like properties in yams can help regulate the hormone balance. Bitter Yam balances hormones to help regulate the body’s menstrual cycles. Regular cycles are crucial for women who are trying to conceive.

- Research has shown that bitter yams have an ovulation stimulating substance that can help boost fertility.