Hoodia gordonii: an overview of biological and botanical characteristics: Part I

Townsend Letter for Doctors and Patients, Nov, 2006 by Stephen Holt, Thomas V. Taylor

Hoodia gordonii is a cactus-like plant from Southern Africa that contains substances which suppress hunger, appetite, and thirst. (1-24) The use of Hoodia as an appetite suppressant is supported by colorful folklore history and recent scientific studies. (1-24) Hoodia is well known to the San bushmen of South Africa who are associated with the folklore medical use of this plant. (1-3) From the teachings of their forefathers, the San learned to eat this plant to reduce hunger sensations. (1-3) It is reported that the San bushmen of South Africa believe that Hoodia is their food, water, and medicine. (1,2)

The Hoodia plant grows in the Kalahari desert region of Southern Africa, including Namibia, Angola, and Botswana. (1-2) History records that the San people of the Kalahari desert used the Hoodia plant to reduce hunger and thirst when they traveled across the desert. (25) This nomadic, ancient group of people was often deprived of food on long hunting expeditions in the desert, and famine was common. (1-3,25,26) In this Part I, of a two-part article, general background information on Hoodia gordonii is reviewed, with a focus on its botanical and biological characteristics.

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Botanical Information on Hoodia gordonii

The succulent plant Hoodia gordonii belongs to the family of plants known as Asclepiadaceae. (1-3,26-31) There are at least 2,000 species of the Asclepiadaceae group of plants, and half of these species are succulents. (1,2) The term succulent, applied to a plant, implies that the body of the plant is full of juice and has fleshy tissues that will conserve water. Breaking the skin of the plant Hoodia results in the flow of juices and presentation of "plant flesh."

Hoodia is a genus within the family of Asclepiadaceae. (32) Although a variety of species of Hoodia are found in the desert regions of Southern Africa (Kalahari, Botswana, and Namibia), not all varieties of Hoodia have been used as appetite suppressants. (1,2) The principle, prized plant of the San bushmen of Southern Africa is Hoodia gordonii. (3)

There may be more than 20 different species of Hoodia that grow in Southern Africa. (1,2) These plants grow in short clumps with a vertical stem that is pale green in color. (1-3,26-31) Attempts to farm the species Hoodia gordonii outside its normal habitat have been generally unsuccessful, with notable exceptions. (1,3) Hoodia plants are extremely difficult to grow, and they need a lot of care and attention, with obligatory requirements of watering, sunlight exposure, and specific seasonal temperatures. (1-3,32,33)

It is very difficult to provide a simple understanding of the botanical characteristics of Asclepiadaceae for several reasons. This family of plants shows remarkable biodiversity, but many are fly-pollinated, leafless succulents with fleshy stems that branch close to the ground. (1,2) Many of these succulent plants have small thorns, and some present different colored flowers at various times of the year. (1,2,32) Certain species of Hoodia bear fruit (Hoodia currorii), whereas some show prominent flowers that look like miniature satellite discs (Hoodia gordonii or currorii). In addition, some Hoodia flowers look like small thorny stars (Hoodia flava). Hoodia currorii and gordonii have purplish or reddish flowers, whereas Hoodia flava has a yellow flower. (1,2,32) In general, the flowers of Hoodia species produce a smell similar to rotten food. This scent is believed to attract insects that cross pollinate several species of Hoodia. (1,2)

There is no doubt that several species of Hoodia have been eaten for thousands of years as raw or cooked food, especially by rural inhabitants of the Northern cape of South Africa and adjacent countries. (1-3) It would appear that Hoodia is still consumed by individuals who tend animals in arable locations. (1,2) B-E. Van Wyck and N. Gericke report that shepherds of the Kalahari desert use fresh, raw Hoodia as a way of suppressing appetite and thirst. (2) These authors describe species of Hoodia as an emergency source of food and water in the harsh and dry desert environment.

The stems of Hoodia plants that have had their spines removed are the preferred portion of the Hoodia plant for eating. (1,2) Some manufacturers of dietary supplements describe the use of stems in their product, but this statement is quite inaccurate, because it is the whole aerial part of the plant that is dried for the preparation of bulk Hoodia powder. (3) Hoodia species have a bitter taste, which is quite noticeable after eating Hoodia gordonii. (3,18)

Against this background, one may understand that there may be difficulty in identifying only one species of Hoodia during harvesting for use in dietary supplements. Of course, it is Hoodia gordonii that has the principle, reported properties of appetite suppression. This is the species that has been the focus of most contemporary scientific research. (1-40)

The similar appearances of different species of Hoodia mean that the correct harvesting of this plant relies very much on the knowledge of local farmers or harvesters in Southern Africa. (1-3,18,28,29) It is believed that descendants of the San bushmen are the most knowledgeable concerning the identification of edible species of Hoodia. (1-3)