Coffee, Tea and Cocoa – Botany, Therapeutic Uses, Constituents, Pharmaco, Adverse Effects

Caffeine, a central nervous system stimulant, is the most widely used plant product in the world. Virtually everyone has experienced its pharmacological effects. It is estimated that the amount of caffeine consumed daily is the equivalent of one cup of coffee for every man, woman, and child on Earth. This rate of intake is understandable as caffeine is a component of numerous consumer products. Besides coffee, caffeine is present in tea, cocoa, chocolates, maté, soft drinks, and various over-the-counter medications. The chief plant sources for caffeine are the shrubs Coffea arabica and Coffea canephora, and the trees Camellia sinensis and Theobroma cacao. The species epithet arabica was given to the coffee plant because of its place of origin. Camellia is the latinized version of Kamel, the surname of a Jesuit pharmacist and botanist who lived in the Philippines, and sinensis is Latin for “from China.” Theobroma is Greek for “food of angels,” and Cacao derives from the Aztec term cacahuatl, which means “bitter water.” This describes the taste of the brew made from the unprocessed chocolate. Cacao is the name of the plant and its extract, whereas cocoa is the beverage made from the chocolate produced by this plant.

The genus Coffea is native to Africa and the Arabian Peninsula, Camellia to China and Southeast Asia, and Theobroma to tropical portions of the Americas. Over the centuries, armed conquest, exploration, and trade routes spread these plants, and their uses, around the globe. The popularity of caffeine has continued to grow unabated. Although it is possible to synthesize the caffeine molecule, it is still chiefly obtained from plants.

Prior to the fifteenth century, coffee beans were produced only in Africa. The use of coffee as a beverage spread from Ethiopia and Yemen to Egypt and then to Turkey. Bunchum, an Arabian coffee, was first described in the ninth century by al-Razi, a Persian physician. It was noted that consumption of coffee could prolong the number of hours worked. By the seventeenth century coffee was being enjoyed throughout Europe.

The documented history of tea predates that for coffee. Records indicate that tea was prepared for Chinese royalty as early as 3000 BC.

Archaeological findings suggest that beverages from the cacao plant were consumed in Mexico 4,000 years ago. Constituents of the cacao bean have also been identified in 2,600-year-old Mayan pottery. It is known that Mayans held an annual celebration to pay homage to the cacao god. It was used by Native Americans as an herbal remedy and for cooking. Their awareness of its stimulant properties is evident from writings indicating they consumed a chocolate drink to relieve fatigue. It is thought that Columbus was the first European to taste a cacao bean. Cacao and chocolate remained unknown in Europe until the seventeenth century when the plant was brought to the European continent by Spanish explorers.

Caffeine is an excellent example of a plant product that can affect brain function. Because it is derived from a variety of unrelated species, no single plant is highlighted in this post. Rather, the focus is to consider the sources and pharmacological properties of caffeine to demonstrate how such information is useful for defining the clinical utility of a plant constituent. A discussion of caffeine also emphasizes the pharmacological potential of alkaloids as compared with other types of plant chemicals. Whereas the relatively recent discovery of galantamine in daffodil illustrates how difficult it can be to identify plant constituents having subtle effects on brain function, caffeine is an example of how straightforward the discovery process is when the central nervous system effects are obvious. This provides an important lesson for consumers interested in assessing the potential effectiveness of an herb for treating a central nervous system disorder. As shown by caffeine, it is relatively easy to obtain data demonstrating a definitive, predictable, and consistent response to a plant constituent if its effects are readily apparent. While the stimulating effects of these plants have been appreciated for thousands of years, it was not until the nineteenth century that caffeine was first isolated from them. This made it possible to demonstrate that caffeine was the constituent most responsible for the central nervous system effects of these plants. Unlike many of the herbal products sold today, it was evident to all even before the modern era that these plants contain pharmacologically active constituents.