In Nigeria there is a town known as the twin capital of the world, they put banners up all over to show how proud they are of this title, despite not really knowing why there are so many twins in the area. Anyone who walks around Igbo Ora in Nigeria will see many duplicate faces, rows, and rows of children in their schools have identical siblings.
In the Yoruba ethnic group twins are very common, and as it is the group that dominates Nigeria, it means there are a lot of twins in Nigeria. In the southwest, a study took place in the 1970s by a British gynecologist who found out there were around 50 sets of twins to ever 1000 births. And that is the highest twin birth rate in the world.
In Yoruba culture twins are actually so common they have special names to differentiate them, Taiwo and Kehinde which depends on if they were born first or second. However, even by Yoruba standards, the town of Igbo Ora is considered a rarity and to be extremely exceptional. If you look through one hundred children, you will most likely find 10 sets of twins in the town.
The common view is it caused by the okra leaf they love to eat and munch throughout the day, the leaves are also used for a very popular stew that is eaten in Igbo Ora. And others believe it to be due to the other popular dish Amala which is made from yams and cassava flour. The theory is this food stimulates the production of eggs and this is why there are more twins.
But a local obstetrician Ekujumi Olarenwaju based out of Lagos believes that the phenomenon has to be related to something else. Other cultures in different parts of the world have the same yams based diet and do not have this many twins being recorded. Ekujumi believes the answer is simply genetics, the region has had a lot of inter-marry over the years and this has caused the genes that cause twins to be pooled and concentrated.
The local woman of Igbo Ora disagrees and says it is down to their okra leaves and how they prepare them specially. Oyenike Bamimore who has had eight sets of twins, says she is living proof that the okra leaves cause twins as she eats them constantly.