WHILE MANY doctors in Jamaica do not yet feel comfortable to prescribe guava tea for diarrhoea, it is a safe complementary medicine, validated by over eight international clinical trials.
The fruit has a distinctive, savoury-fresh aroma that is thermostable and thus survives processing. Guava fruits are also a good source of pectin, an enzyme used in making jam as well as promoting digestion. Guava is higher in vitamin C than citrus and contains appreciable amounts of vitamin A as well.
The fruit can be eaten raw, used in jams, juices and as a popular dessert made by preparing a thick jelly paste, which is cut into squares before serving.
Guava (Psidium guajava) is an evergreen tree reaching a height of 3-10 m. The trunk is slender with a greenish-brown scaly bark, which peels off in thin flakes. The white flowers are either solitary or in groups of two or three. The fruit is round, ovoid or pear-shaped.
It has a thin greenish-yellow skin and a flesh of varying thickness, which may be white, yellow-pink or red. Some varieties are seedless. The flavour is variable but is distinguished by a characteristic and penetrating musky aroma of varying intensity.
Guava, a native of tropical America, is well distributed throughout the tropics and subtropics. Although the guava plant was domesticated more than 2,000 years ago, it was not until 1526 that the first commercial cultivation of guava was reported in the Caribbean islands.
All parts of this tree have been used for a variety of ailments in traditional medicine. Guava has been found to contain a large number of phytochemicals (>79) including lycopene and beta-carotene.
Gargling with a leaf infusion helps mouth sores (oral ulcers) and bleeding gums.
A tea made from the leaves and/or bark has been used for diarrhoea and dysentery, for stomach upsets, vertigo and to regulate menstrual periods. A cup of tea made by boiling guava leaves will stop diarrhoea within hours.
Leaf decoctions are used as a remedy for coughs, throat and chest ailments, an emmenagogue and vermifuge, to treat lencorrhoea; it has been effective against vomiting and diarrhoea in cholera patients. Also used to clean wounds and accelerate healing.
Guava fruit has been studied and has demonstrated hypoglycemic properties. Guava is also rich in fibre. It helps prevent constipation.
The wood is used in carpentry and turnery, or as fuelwood. The bark is used for tanning. Black dye can be obtained from the leaves.
Lycopene is a carotenoid producing the colour to tomatoes, guava, and pink grapefruit. It is not destroyed in cooking or processing and is twice as abundant in food as beta-carotene. Unlike other carotenoids, lycopene does not convert into vitamin A. Lycopene's biggest claim to fame is its cancer-inhibiting effects, especially prostate cancer. It also beefs up resistance to bacterial infections, is an excellent antioxidant and protects against cardiovascular disease.
Most of the health benefits attributed to guava is due to its antimicrobial activity against certain bacteria such as Staphylococcus aureus and beta-streptococcus group A, and enterobacteria pathogenic to man enteropathogenic Escherichia coli, Salmonella enteritidis, Salmonella typhi, Shigella dysenteriae and Shigella flexneri - (J Ethnopharmacology, 1990. 30(1): 55-73).
In traditional medicine today, guava is still employed as a natural medicine. Guava leaves still remain in the Dutch pharmacopoeia and the leaves are still used as a diarrhoea treatment in Latin America, Central and West Africa, and Southeast Asia. This long history of use has led modern-day researchers to study guava leaf extracts and its uses as an effective treatment for gastrointestinal disorders.
Source: <http://agrolink.moa.my/
comoditi/guava/guava.html>; <http://www.rain-tree.com/guava.htm>
Dr. Sylvia Mitchell, research fellow (Graduate School), Biotechnology Centre, University of the West Indies, Mona, email:smitchel@uwimona.edu.jm
