At a dusty playground in southwest Nigeria, school children line up to return to their classrooms. Many of their faces have exact matches within the group. That is because an unusually large number of children in this part of Nigeria are identical twins.
Sights like this can be seen everywhere in Igbo Ora. A sign even welcomes visitors to the “twins capital of the world.”
Twins are common in the Yoruba ethnic group found in this part of the country. A 1970s study by a British doctor found that about 50 sets of twins were born out of every 1,000 births in the country’s southwest. That is one of the highest rates of twin births in the world.
In Yoruba culture, twins are so common that they are traditionally given specific names. They are called either Taiwo or Kehinde -- depending on whether they were born first or second.
But even for Yoruba people, Igbo Ora is considered to be exceptional. Among the nearly 100 school children who gathered at the end of their break, 18 were twins.
“There are so many twins because of the okra leaf that we eat,” said 15-year-old Kehinde Oyedepo, who is a twin.
Many in the town believe this is the reason for the high twin birth rate. The leaves are used to make a hot meal that is popular in Igbo Ora.
Others have pointed to the popularity of Amala - a local food made from yams. One theory is that yams activate the production of a chemical agent that stimulates egg production in women.
Ekujumi Olarenwaju is a doctor based in the Nigerian capital of Lagos, about 160 kilometers from Igbo Ora. Olarenwaju believes the cause must be something else, because the same kind of yam is eaten in many parts of the world -- without the same results.
He suggested the cause may be because the genes that often lead to twins have become highly concentrated in this area.
But the women who sell okra leaves at a town market are quick to disagree with the doctor. They say how locals eat the leaves is critical. For example, a stew made from the okra leaves should be eaten immediately and never stored.
Oyenike Bamimore said she was living proof that diet helped explain the high number of twin births. She said, “Because I eat okra leaves a lot, I gave birth to eight sets of twins.”
I'm Ashley Thompson.
The Reuters news agency reported this story. Ashley Thompson adapted it for VOA Learning English. Hai Do was the editor.
Words in This Story
specific - adj. special or particular
identical - adj. exactly the same
twin - n. either one of two babies that are born at the same time to the same mother
concentrated - adj. existing or happening together in one place : not spread out
stew - n. a dish of vegetables and usually meat cooked in hot liquid for a long time
diet - n. the food that a person or animal usually eats
stimulate - v. to make (something) more active
okra -n. a tall plant whose pods are eaten as a vegetable and are used in soups and stews
yam - n. a long, thick root of a tropical plant that has rough brown skin and usually white or yellow flesh and that is eaten as a vegetable