Kola Nut

Kola trees are evergreen rainforest species growing up to about 20 metres, with glossy leaves and star-shaped, yellowish flowers. The fruit is a cluster of star-shaped, knobbly pods, each containing four to ten large seeds in a white or pink-red seed coat. The seeds are fleshy, about 3 to 5 cm long, and range from white to red or pink. Fresh nuts are crisp and bitter, with an astringent taste that is followed by a slight sweetness. Cola nitida has seeds with two cotyledons, while Cola acuminata usually has more. Seeds are sold fresh, wrapped in leaves to keep moist, or dried, powdered or as extract.

Both species are native to the tropical rainforests of West Africa, from Sierra Leone and Guinea through Ivory Coast, Ghana and Nigeria. Cola nitida is concentrated in the western part of the range, while Cola acuminata is more common in the east. The word kola is derived from West African languages, and the nut is called goro in Hausa and obi in Yoruba and Igbo, depending on the type. Kola trees were introduced to the Caribbean and Brazil during the transatlantic slave trade, and to other tropical regions.

Kola nut has had a central place in West African culture for centuries. It is offered to guests as a gesture of hospitality, shared in ceremonies of marriage, naming and conflict resolution, and used in oaths and rituals, especially among the Igbo, Yoruba and Hausa. Caravans carried the nuts north across the Sahara along trade routes, and the trade linked forest and savanna regions, with the nuts valued as a stimulant that suppressed hunger and fatigue, and in Muslim regions as an acceptable stimulant. Arab and European travellers described the trade from the Middle Ages onwards. In the nineteenth century, kola extract became an ingredient in tonics and soft drinks, notably Coca-Cola, which originally contained kola and coca extracts, although today most cola drinks use synthetic or other flavourings and only trace amounts, if any, of kola. West Africa remains the main producer, with Nigeria the largest, and the nuts are traded across the region. Cultivation has faced competition from other cash crops, and the tradition continues to be socially important.

Fresh nuts are chewed whole or in pieces, usually after removing the seed coat, as a stimulant, and are offered in social and ceremonial settings. Powder and extract are used in energy drinks, tonics and some herbal products. Traditionally, kola was chewed to ward off hunger and fatigue, and to improve the taste of water. The pods and bark have local medicinal uses. Dried nuts are used in some dyes, and red kola is distinguished from white in ritual use.

Kola nuts contain caffeine, usually around 1 to 3 percent, plus theobromine and polyphenols such as catechins. Their stimulant effect is similar to that of coffee, including improved alertness and temporary reduction in fatigue. Research on other health effects is limited, and traditional claims, for example about digestion or appetite, are not well supported by clinical trials.