Kola Nut

Edmund Abaka. Cambridge World History of Food. Editor: Kenneth F Kiple & Kriemhild Conee Ornelas. Volume 1. Cambridge, UK: Cambridge University Press, 2000.

Kola nut is an important stimulant and masticatory in Africa. It is about the size of a walnut or a chestnut and varies in color from dark red to creamy white (Chevalier and Perrot 1911; Cohen 1966; Agiri 1972; Lovejoy 1977-8, 1980). This fruit of the kola tree grows in pods that contain from 3 to 15 or more nuts. Pink and white nuts are generally valued highest because they have a sweeter taste and a greater caffeine content than other kola nuts. Kola is richer in caffeine than coffee and most teas and has 3 times as much starch as cacao (Heckel and Schlagdenhauffen 1884; Kraemer 1910; Chevalier and Perrot 1911; Pratt and Youngken 1956; Ramstad 1959). Known by various African names—goro or gourou, ombéné, nangoué, kokkorokou, and matrasa—kola is known as a heart stimulant because it contains kolanin along with caffeine, traces of the alkaloid theobromine (which exists in cacao as well), glucose, and strychnine (Table III.8.1). Both caffeine and theobromine stimulate the nervous system and the skeletal muscles, making kola a psychoactive substance (Kennedy 1987; Jones 1995).

Kola Production

The genus Cola is of tropical African origin (Freeman 1893; Irvine 1948; Cohen 1966; Dickson 1969) and belongs to the Sterculiaceae family, the species of which are most abundant in tropical Asia (Oliver 1868; Heckel and Schlagdenhauffen 1884). A number of different species grow in the region between Sierra Leone and the Congo (Heckel and Schlagdenhauffen 1884; Kreiger 1954; Kola 1957; Dickson 1969; Morgan and Pugh 1969; Brooks 1980; Anquandah 1982). But of some 40 varieties, only Cola nitida and Cola acuminata are well known and widely used. The former was the kola of long-distance trade, whereas the latter was grown mainly for local consumption in the forest regions of Africa.

Before the nineteenth century, C. nitida was only produced west of the Volta River, and C. acuminata grew to the east, especially in Nigeria (Lovejoy 1980; Goodman, Lovejoy, and Sheratt 1995). In the nineteenth century, however, the cultivation of Cola anomala and Cola ballayi had spread to southern Cameroon, with the nuts exported to the savanna region (Goodman et al. 1995). In Ghana, in addition to C. nitida and C. acuminata, there are Kola other varieties that include Cola cardifolia, Cola togoensis (Engl & Krause), Cola johnsonii (Stapf.), and Cola verticilata (Stapf. & Chev.) (Irvine 1969).

Although kola is indigenous to the forest zone of West Africa, the plant has traveled widely. It can be found in East Africa around Lake Nyanza, along the north coast of South America, and in portions of South Asia. In large part, this is because of European colonization. The British, for example, introduced kola into the East Indies, the Seychelles, Ceylon (Sri Lanka), Demerara (Guyana), Dominica, Mauritius, and Zanzibar. Similarly, the French introduced kola into Martinique, Guadeloupe, and Cayenne (Heckel and Schlagdenhauffen 1884).

Cultivation

Kola does well in forest soils and also in savanna areas of forest outliers so long as there is adequate moisture in the rooting zone and the soil has a high content of organic matter. The tree likes low elevations, deep, well-drained soils, and moderate rainfall. Good drainage is essential because the plant cannot withstand flooding (AERLS Guide 1982). It grows best in rich, deep soil in forest zones where rainfall does not exceed 50 to 60 inches annually—conditions characteristic of areas where the kola industry has persisted on a commercial scale (Heckel and Schlagdenhauffen 1884; Miles 1931).

The kola tree also flourishes in moist lands either at sea level or a little above. In Labogie in Nupe (Nigeria), kola plantations are situated in sheltered valleys at an elevation of 450 to 550 feet above sea level, where, according to a Royal Botanical Garden bulletin, “[t]he soil is a deep, black, sandy loam and is kept in a continuous state of moisture by streams that are in the valley” (1906: 89).The annual rainfall in this region is about 40 to 50 inches. Similarly, in southwestern Nigeria, kola is generally found in the better-drained areas with light, loamy soils of good depth (Russell 1955;Agiri 1972).

Germination

Polyembryo (in which more than one embryo results from a single ovule) occurs in C. nitida (Bodard 1954) and C. acuminata, along with multiple shoot/root production and adnation of auxiliary shoots to the main stem axis (Oladokun and Adepipe 1989). In fact, splitting or cutting the nuts brings quicker germination, although this reduces nut size, as well as initial growth after germination is slowed down. In addition, some of the cotyledons produce multiple roots and shoots, whereas others produce roots with no shoots (Oladokun and Adepipe 1989; Brown 1970).

High temperatures and light seem to have no effect on kola germination. Seeds that are freshly harvested take 3 to 9 months to germinate, although seeds stored for about 7 months usually do so within 3 or 4 months of sowing. There is also a pronounced difference between the germination patterns of stored and fresh kola seeds, with seedlings from stored seeds tending to grow faster, larger, and more vigorously than those from fresh seeds (Ashiru 1969; Brown 1970; Karikari 1973).

Propagation

The propagation of kola nuts takes place after the land is prepared at the beginning of the rainy season. The farmer initially clears a portion of the forest and scrapes the soil into “hills” that are “beds” for yam, cassava, and cocoyam. Kola seeds are planted between these beds and spaced about 20 to 27 feet apart so that the food crops will provide shade for the young seedlings (Ashiru 1969; Brown 1970; Karikari 1973).

A kola tree bears fruit after 4 or 5 years and reaches maturity by the tenth year. Because it is a tree of the tropical forest, it is useful to interplant with food crops or with shade trees, such as coffee and cacao. Many of the kola groves or plantations in Ghana are found growing together with cacao (Ossei 1963). Because growth is very slow (about 3 meters in 4 years), the use of seed, rooting of cuttings, grafting of shoots on suitable rootstocks, budding, and aerial layering—or marcottage—are all techniques that have been employed to make seedlings available to farmers who have embraced the crop.

If kola is to be propagated from the seed, the nuts are taken from the pod and wrapped in plantain leaves. Then they are buried in the ground and watered every day until they sprout, after which the young seedlings are transplanted to bear fruit some 4 to 5 years hence (N.A.G. [Kumasi] 1905; Quarcoo 1969; AERLS Guide 1982; Szolnoki 1985). Seedlings are also raised in bamboo pots before being transplanted in the field. In some cases, bananas and plan-tains provide shade for the young plants (Ossei 1963).

Kola is also planted by one or another of four methods of vegetative reproduction (Pyke 1934). In the first, a branch of a healthy kola tree is cut into 2-to 3-foot-long pieces, which are then planted. After germination, these bear fruit in 2 or 3 years (N.A.G. [Kumasi] 1905; AERLS Guide 1982). Plant cuttings, one of the most frequently used present-day techniques in cloning fruit trees, is also one of the most ancient methods of vegetative propagation (Archibald 1955; Jones 1968; Ashiru and Quarcoo 1971; Ibikunle 1972; Ashiru 1975). It is very important that cloning be done only from high-yielding kola trees and, more importantly, from trees with a high degree of self- and cross-compatibility.

A second method of vegetative propagation is grafting. Various methods of grafting have been used in the production of kola clones (Ashiru and Quarcoo 1971; Gnanaratum 1972), with wedge grafting, saddle grafting, and the splice and whip-and-tongue grafts said to yield the best results (Jones 1968). In Nigeria, the side-and-wedge grafting technique is widely used.

Budding is a third method of vegetative propagation of kola. Nursery budding ensures the production of vigorous budlings and offers the possibility of virtually all of them continuing to bud in the field. By contrast, in situ budding cannot guarantee that 100 percent of the buds will take, although these usually do grow faster than those transferred from the nursery (Archibald 1955;Are 1965;Ashiru and Quarcoo 1971; Ibikunle 1972;Ashiru 1975).

Aerial layering (also known as marcottage) is the fourth method of vegetative propagation by which “an intact branch of a kola tree is induced to produce roots before it is severed from the mother tree” (Ashiru and Quarcoo 1971). After being severed, the cutting may be raised in a nursery or planted directly in the field. Branches that are growing vertically, or nearly so, are the best types to select for marcotting, and such branches should be between 2 and 3 years old. As a method of kola propagation, marcottage is old and well known, but it is also very cumbersome (Toxopeus and Okololo 1967).

Kola is—or at least was—sometimes planted on special occasions. In some cultures of sub-Saharan Africa, for example, it was the custom to bury the umbilical cord of a newborn baby with a kola seed. This indicated a safe delivery, and the kola tree that subsequently grew up became the property of the child. Cultural taboos also play a role in kola planting: In some parts of West Africa, a belief (perhaps spread to limit competition) that “he who plants kola will die as soon as the plant has flowered” militated against its cultivation. Instead, farmers looked for self-sown seedlings and transplanted them (Russell 1955).

The Kola Trade

From time immemorial, the forest and the savanna regions of Africa have been complementary in basic natural products. This complementariness—based on the very different requirements of forest and savanna dwellers—stimulated long-distance exchange between the Volta basin and the Upper Niger (Denham and Clapperton 1826; Lander 1830; Dupuis 1894; Hallet 1965; Bowdich 1966; Arhin 1987). Gold, kola nuts, and salt from the coast constituted the most important items of trade in the Volta Basin of West Africa (Wilks 1962; Fynn 1971).

Evidence from the Esmeraldo de Situ Orbis—penned by one of the earliest Portuguese explorers, Duarte Pacheco Pereira—attests to the existence of the West African kola trade as early as the sixteenth century. A materia medica written in 1586 for the Moroccan sultan, Ahmed al-Mansur, mentions that kola was brought from the western Sudan—from “a place called Bitu where there are mines of gold and gold dust” (Wilks 1962: 15).

C. nitida, as an export crop, is reported to have originated in the hinterland of what is now Sierra Leone and Liberia, where it appears to have been commercialized by people who spoke a language of the West Atlantic family of Niger-Congo. People of the Mande branch, who subsequently moved to the forest zone, became the major producers in the fourteenth century.The kola nut trade was then monopolized by Muslim Mande traders who traveled widely throughout the western Sudan (Goodman et al. 1995). By the fifteenth century, the cultivation of C. nitida had spread throughout the Ivory Coast region and the Volta basin. It was also being grown in the forests of Sierra Leone, Liberia, and the Ivory Coast, and in the Volta basin of Ghana.

Coastwise trade in kola led to the creation of two diasporic communities—the Bahun commercial network, linking the lower Cacheu River with the Casamance River and the Gambia River, and a parallel Mandinka network to the east, linking the Upper Geba and Upper Casamance with the Middle and Upper Gambia and Upper Niger (Brooks 1980). Although this kola trade antedated the arrival of the Europeans, when Portuguese traders did reach West Africa, they quickly recognized the commercial importance of kola. With the help of African mariners, they began to participate in the kola trade while systematically concealing that participation from royal regulation and sanction (Brooks 1980).

In the eighteenth and nineteenth centuries, the Gold Coast and Sierra Leone supplied kola to northern and, later, southern Nigeria (Gold Coast Blue Books 1884-1925; Miles 1931). During the last half of the nineteenth century, however, demand for Gold Coast kola nuts mounted in Britain (Table III.8.2), France, Germany, and the United States, where the nuts were employed in the production of “neo kola,” cola-based soft drinks, and pharmaceuticals (Gold Coast Blue Books 1884-1925).

The overseas kola trade from the Gold Coast to Europe and the United States developed in three phases. It began with the export of two packages of unknown weight to England in 1867 (Dickson 1969) and continued to grow until, in 1884 and 1885, 400 packages of kola, worth more than £2,000, were sent to Europe and the United States (Gold Coast Blue Books 1884, 1885; Freeman 1893; Dickson 1969).

The second phase of the southern kola trade, which saw the export of kola to Brazil from the 1890s until the 1920s, took the form of exports directly from Ghana, as well as reexports of Ghanaian kola nuts from Nigeria to Brazil (Gold Coast Blue Books 1888-1920; Alex 1890).

The third and final phase of the southern kola trade involved exports to Nigeria in the first decades of the twentieth century. The ports of Accra, Winneba, Saltpond, Apam, and Cape Coast became outlets for the these shipments of kola by sea.

The southern axis of the kola trade was also spurred by the purchase of kola by African and European companies trading along the coast of Ghana and by improvements in communication, such as the construction of roads and railways and the introduction of motor transportation, along with mail boats, steamers, and ferries (Danquah 1928; N.A.G. [Accra] 1959; Dickson 1961).The result was a significant increase in kola trade volume.

From the mid-1920s onward, however, the market demand for Ghanaian kola began to decline. One reason was the beginning of large-scale kola cultivation in Nigeria in the 1920s and 1930s (N.A.G. [Accra] 1959; Cohen 1966;Agiri 1977). But another factor was that cacao, now an international crop, had gradually supplanted kola as the backbone of the Gold Coast economy. It is worthy of note, however, that because of interior African markets, the decline in kola exports to Nigeria did not mean a collapse of kola production in Ghana.

Uses of Kola

In the Past

Initially a luxury item, kola later became an item of common usage. Those who grew it, as well as those who used it, often ascribed therapeutic, dietetic, and pharmacological properties to kola. In addition, according to volume 14 of the American Druggist (1885), kola was to some extent employed as a substitute for food, in much the same way as coca has been used by residents of the Andes. Indeed, kola is to the African what tobacco or coffee is to the European or betel is to the southeastern Asian—a stimulant and a psychoactive substance (Simmonds 1891; Kumm 1907; Goodman et al. 1995).

The importance of kola as a drug was first recognized outside Africa in the twelfth century by an Arabian physician, who wrote that it was used in the form of a powder for colic and stomachache and had warming properties. A later Portuguese observer testified to the importance of kola nuts thus: “The Black population would scarcely undertake any enterprise without the aid of kola” (Fluckiger 1884: 524), which, among other things, was supposed to protect against the pangs of thirst. However, the first definite mention of kola as a drug came in the work of Odoard Lopez in 1591, and shortly afterward, Andre Alvares de Almada, who had visited Guinea in 1566, wrote his Tratada Breve dos Rios de Guiné do Cabo Verde (1594), in which he claimed that kola and betel were used in more or less the same way. At the end of the sixteenth century, James Garet, an apothecary and amateur collector of foreign curios, brought the nuts to the attention of the celebrated Flemish botanist-physician Carolus Clusius (Charles de l’Ecluse) (Fluckiger 1884).

As knowledge of kola reached the outside world, the plant itself began to travel, apparently reaching the Caribbean as early as the seventeenth century. This came about following an urgent request, sent through a Guinean trader by an agent for Jamaican slaveholders, for kola seedlings—urgent, because of kola’s well-known property as “a medicinal prophylactic agent or as an ordinary article of food, to avert, as far as practicable, those attacks of constitutional despondency to which … Negroes were peculiarly liable” (Attfield 1865: 456-7).

Many accounts of the properties of kola by early writers were borrowed from travelers and were therefore probably exaggerated or distorted to some degree. Since the 1850s, however, research has been carried out by botanists, chemists, and pharmacists on some of the properties ascribed to the kola nut. For example, A. M. F. J. Palisot-Beauvois (1805) asserted that the Negroes of Oware used kola nuts because of the nuts’ remarkable ability to impart a pleasant taste to all food or water consumed. Subsequent experiments have confirmed this observation, at least for drinking water, which, even when comparatively stale or impure, becomes quite palatable to the consumer after chewing kola. It is possible that the action of the chemicals in kola on the palatal mucosa creates the “illusion” of sweetness, or perhaps this is the result of kola’s high caffeine content.

Another report—this by N. Hudson (1886), a medical inspector in the U.S. Navy—on the results of administering kola paste to a patient suffering from rheumatism, dyspnea, and headache, amply demonstrates some of the pharmaceutical and pharmacological properties of the kola nut. Hudson wrote:

The patient, a lady of 36, had suffered during childhood from rheumatism. Up to a recent period, however, she had been in good health and able to lead a busy, active life. Eighteen months since, she was attacked with severe endocarditis, from which she recovered slowly, and with a damage to the mitral valves… The action of the heart was feeble and irregular, and there was a good deal of dyspnoea, faintness, and fatigue upon even slight exertion. She had always been subject to occasional headaches, and these now became periodic and severe, occurring at first at intervals of four or five weeks, and lasting two days. Latterly they had increased in frequency and intensity, coming on about twice a month, each attack causing three days of suffering so severe as to fill the patient’s mind with constant dread of a recurrence.The discovery of a ratio of urea much below that of normal urine, with the existence of an occasional granular cast, established the conviction that the headaches were uraemic in character (1885-6: 711).

After about three months of administering kola paste in hot milk at a dosage of about 10 grams once or twice daily, Hudson reported:

During the first nine weeks of its use there was no recurrence of headache. Then there was a comparatively mild attack, which may fairly be attributable to a suspension of the use of the kola in consequence of the marked improvement. The general condition has materially improved, the heart’s action is more regular, and the attacks of dyspnoea and faintness have nearly disappeared. The most characteristic effect seems to have been an immediate relief of a sense of fatigue, a sense of bien-être and cheerfulness to which the patient had been long a stranger. The employment of the kola seemed to be satisfying the appetite, for whenever taken, it appeared to serve as a substitute for the following meal. But the nutritive processes were not impaired: on the contrary, the bodily weight increased from ninety-eight to one hundred and five pounds. No marked change in the character of the urea has been observed. The quantity voided has somewhat increased, but the total urea excreted remains at about ten or twelve grammes daily (1885-6: 711).

As Hudson noted, the results of the administration of kola paste were marked and immediate, producing a definite and positive change in the well-being and comfort of the patient (Hudson 1885-6: 712).Thus, as stated by another observer who was a contemporary of Hudson, kola can become a “sustaining and stimulating adjunct in exhaustive and wasting diseases” (Simmonds 1891: 10).

It was also believed that kola “exercises a favourable influence upon the liver, and that white people, living in those regions [where it grows], who chew a small quantity before meals escape constitutional changes due to affections of that organ” (Heckel and Schlagdenhauffen 1884: 585). Finally, kola was said to be advantageous for sportsmen, athletes, and “brain workers” in reducing tension (Uses of kola nut 1890).

Current Ethnopharmacology in Africa

Kola nuts are used for the treatment of certain infections and conditions, such as guinea worm, migraine, and ulcer (Mr.Ansong, Kumasi Cultural Centre, March 5, 1995, personal communication). In the case of guinea worm, the nut is chewed into a paste and applied to the affected portion of the body, and in Ghana, such a paste is used to treat a skin ailment commonly called ananse. Fresh kola nuts are also chewed as a stimulant to counteract fatigue (Szolnoki 1985; Burrowes 1986). Kola is used in beverages—such as coffee, tea, and cocoa—to cure indigestion and nervous or bilious headache. It should be pointed out that the medicinal action of kola is not the same as that of an analgesic taken for pain. Kola is not used because of an isolated chemical ingredient; it is used as a complex whole.

Along with the nut, other parts of the kola tree are also employed for their medicinal properties by traditional healers and the peoples of rural Africa (Mr. Anin-Agyei, Dwaben State Oil Palm Plantation, February 28, 1995, personal communication; Mr. Forster, Dwaben State Oil Palm Plantation, February 28, 1995, personal communication; Mr.Ansong, Kumasi Cultural Centre, March 5, 1995, personal communication).The bark is used to treat swellings and fresh wounds, and the roots provide excellent chewing sticks for cleaning the teeth. The pod bark is mixed with other ingredients to become a traditional medicine for reducing labor pains during childbirth (Akhigbe 1988). The latter is very important because traditional birth attendants play a dominant role in rural Africa’s health delivery system. Most of the people live outside the cities, and the overwhelming majority of these cannot afford the expense of Western-style medicine. Thus, kola-bark preparations for reducing labor pains are highly prized by traditional birth attendants, even though very little research has been done to determine the properties in kola bark that make childbirth more comfortable for African mothers.

Many people use kola because of its very high caffeine content—one nut contains more caffeine than two large cups of American coffee. It is generally believed that chewing small amounts increases mental activity and reduces the need for sleep (Attfield 1865; Ogutuga 1975; Lovejoy 1980). Consequently, kola is widely used by Ghanaian watchmen (who call it the “watchman’s friend”) in the course of their vigils, as well as by students who work late into the night. Chewing kola also massages the gums and exercises the teeth.

Yet, that kola can be poisonous to animals raises flags of caution. The chemical composition of kola paste makes it a good bait for trapping mice, who often die when they eat it. Similarly, dogs do not survive when they are given maasa (a baked flour meal) mixed with kola paste (Mr. Ansong, Kumasi Cultural Centre, January 30 and March 5, 1995, personal communication). There has, however, been no laboratory analysis to explain the action of the kola paste on either mice or dogs.

Social Uses

Kola provides flavoring for beverages in Africa, Europe, North and South America—indeed, in all parts of the world (Freeman 1893; Irvine 1948; Bovill 1958; Dickson 1969). In the 1870s, kola was mixed with sugar and vanilla as a tonic for invalids and convalescents and was recommended to travelers as an antidote to fatigue and even hunger (Freeman 1893). In 1886, John S. Pemberton, a druggist in Atlanta, Georgia, invented Coca-Cola when he combined coca and kola extracts as a headache and hangover remedy (Louis and Yazijian 1980). Over time, Coca-Cola (minus the narcotic coca) has become the most popular nonalcoholic beverage in the Western world.

The most common social use of kola in several African countries is as a gift of welcome to friends and guests. Doubtless in part, at least, because of the Islamic prohibition against alcohol consumption, kola is widely used by Muslims (Dalziel 1948; Cohen 1966; Dickson 1969; Morgan and Pugh 1969; Church 1975; Agiri 1977; Lovejoy 1980; Anquandah 1982).A Sokoto tradition not only associates kola with the prophet Muhammed but also asserts that he relished it and gave the nuts as gifts to his favorites. His wealthier followers, in turn, gave kola as alms during high festivals (Tremearne 1913, cited in Ferguson 1972; Russell 1955; Lovejoy 1980).

Dietetic Uses

Kola possesses physiological properties that enable those who eat it to undergo prolonged exertion without fatigue or thirst. Kola has also been said to serve as a preventive of dysentery and other intestinal disorders (Fluckiger 1884), and it has been claimed that kola makes people brave in—even eager for—battle. For all these reasons, kola nuts have historically been dispensed to troops on African battlefields. Askia Mahmoud is reported to have supplied kola to his troops in the sixteenth century, and at the beginning of the nineteenth century, soldiers of the Asante army often chewed kola for days during their campaigns, when there was frequently not enough food to go around (Kreiger 1954; Quarcoo 1971).

In 1852, the German explorer Heinrich Barth thought that soldiers of the Sokoto army were addicted to kola because it was usually distributed to them in the evenings before campaigns (Goodman et al. 1995). Similarly, James Richardson observed that the Emir of Zinder used kola to incite his soldiers before slave raids. In 1890, the German war office ordered 30 tons of kola for the army after conducting experiments with the plant during autumn maneuvers the previous year (Uses of kola nut 1890). At about the same time, troops of the West African Frontier Force stationed in East Africa were given kola rations to enhance their battle readiness (Anyane 1963).

Toward the end of the nineteenth century, a series of interesting experiments on the possible military importance (in dietetic and pharmacological terms) of kola was conducted by R. H. Firth on British soldiers in India. Ordered by the surgeon-general of Her Majesty’s forces, these studies indicated that chewing kola nuts not only seemed to depress the appetite and keep thirst at bay but also increased the individual’s energy level and sense of well-being. In addition, the nuts may have proved efficacious in curing hangovers (Firth 1890).

Nearly a century later, studies carried out on the biochemical effects of kola nut extract administered to rats once again demonstrated the stimulating properties of kola in relatively large doses (Ajarem 1990). This is doubtless explicable in part by the caffeine content; however, many more such efforts are required to show why it is that kola has a long-standing reputation as a laxative (but prevents dysentery and other intestinal disorders) and as a heart stimulant (but can also be a sedative). Also demanding explanation are kola’s alleged ability to make foul water palatable and its historical fame as an aphrodisiac, a restorer of potency, and an aid to childbirth (Nzekwu 1961; Quarcoo 1969; Goodman et al. 1995).

Certainly kola seems potent as a drug, but save for the research just mentioned, its potentiality remains to be investigated. Given its many current uses in Africa, as well as its role in the soft-drink industry around the world, it is to be hoped that such research will soon be forthcoming.