How did the columbian exchange affect the African people

The columbian exchange involved many species being brough over from the New Old to the Old World (crops, diseases), but I think I will choose one, one that is very important,

A part of it was the cocoa plant. It's native to the Americas, but today it's mostly produced in Africa, in fact just two small countries: Ivory coast and Ghana produce more than half of world's cocoa!

This has a great influence on their economy.