scientific name: Psidium guajava other common names: Guayaba, guayava, guayabo casero
growing areas: Native throughout Latin America physical description: It is a shade tree that grows to about 30 feet, has a red flaky bark, and produces a very aromatic fruit with a yellow skin and dark pink edible flesh. The inner pulp of the fruit is soft and contains many yellow seeds. traditional uses: Guava is one of a number of plants that do double duty in Hispanic communities. As a food source, it is widely consumed and used in beverages and desserts. The fruit is high in ascorbic acid. European traders spread the fruit to Asia and Africa. The tree's bark is used in the tanning of animal skins, and the wood can be used in construction. Guava has been widely used in Latin American traditional medicine as a treatment for diarrhea and stomachaches due to indigestion. Treatment usually involves drinking a decoction of the leaf, roots, and bark of the plant. It also has been used for dysentery in Panama and as an astringent in Venezuela. A decoction of the plant's bark and leaves is also reported to be used as a bath to treat skin ailments.
availability and dosage: Guava is readily available in food stores, botdnicas, and bodegas throughout Hispanic and non-Hispanic communities in the United States. Dosages vary.
contraindications: None noted.
special precautions: Consult your physician before beginning any use of an ethnobotanical substance for medicinal purposes.
The seeds of the guava fruit have been labeled as digestion-resistant by researchers, which explains how the seeds are dispersed by animals and humans. Guava has also been shown to have the ability to lower blood sugar, but blood sugar levels that are too low can be dangerous, with the risk of disorientation, coma, and even death.
medical research: There have been a number of laboratory studies done on guava, mainly as a way of controlling noninfectious diarrhea, long a significant cause of infant mortality in developing countries. Studies have shown that extracts of dried guava leaves can slow down peristalsis (movement of food through the digestive tract), which increases absorption of fluid and electrolytes and thus reduces both diarrhea and the dehydration it can cause.
In traditional medicine, guava has also been used to lessen pain, combat insomnia, and help children suffering from convulsions, properties that sparked more scientific inquiry. Additional studies done in Malaysia, where the plant grows abundantly, showed that an extract of dried guava leaves had a narcoticlike effect on rats, something researchers attributed to flavonoids present in the plant.
Some of the flavonoids present in guava leaves are also viewed by researchers as having potential antitumor properties. A study done in Mexico used guava leaf extracts in a laboratory setting and found that it showed significant activity against certain human and mouse cancer cell lines.
Chinese and Caribbean traditional medicine have used guava in the control of diabetes, but a study in Mexico found that guava did not lower blood sugar levels in rabbits.