Guava
Parts Usually Used
The leaves, fruit, bark, roots, and flowers. Various parts of the plant, including the leaf and the fruit, are used as medicine, with leaves being the most commonly used for medicinal purposes.
Description of Plant(s) and Culture
Guava is a small tree that grows up to 10 meters high with thin, smooth, patchy, peeling bark. The leaves are opposite, short-petiolate, with oval blades featuring prominent pinnate veins, measuring 5-15 cm long. The flowers are somewhat showy with whitish petals up to 2 cm long and numerous stamens. The fruit is a fleshy yellow globose to ovoid berry about 5 cm in diameter with an edible pink mesocarp containing numerous small hard white seeds.
Where Found
Guava is native to tropical areas from southern Mexico to northern South America, extending throughout Central and South America. It now grows in all tropical and subtropical areas of the world, adapting to different climatic conditions but preferring dry climates. The plant is widely cultivated in India, Indonesia, Pakistan, Bangladesh, the Philippines, Africa, Asia, and many other tropical and subtropical regions worldwide.
In India, although planted in almost all states, Andhra Pradesh, Assam, Bihar, Maharashtra, Uttar Pradesh, and West Bengal are important cultivators.
Medicinal Properties
Guava possesses numerous medicinal properties that have been extensively researched and documented. The plant exhibits antimicrobial, antioxidant, anti-inflammatory, antidiabetic, anticancer, antidiarrheal, hepatoprotective, cardioprotective, antispasmodic, analgesic, antipyretic, immunomodulatory, antihypertensive, anti-allergic, wound healing, and nephroprotective properties.
The guava fruit is a source of vitamin C, fiber, and other substances that act as antioxidants. Antioxidants slow down or stop the harmful effects of oxidation. Guava leaves also contain chemicals with antioxidant and other effects, including phenolic compounds, flavonoids, triterpenoids, sesquiterpenes, glycosides, alkaloids, and saponins. Studies have demonstrated the plant’s effectiveness against various conditions including gastrointestinal infections, respiratory infections, oral and dental infections, skin infections, diabetes, cardiovascular diseases, cancer, malnutrition, women’s health problems, pain, fever, liver problems, and kidney problems.
The antimicrobial properties are effective against 34 bacterial species, 19 fungal species, six protozoal species, and four types of viruses.
Biochemical Information
Guava leaves contain a rich array of bioactive compounds responsible for their medicinal properties. Key components include: Flavonoids: Quercetin, avicularin, apigenin, guaijaverin, kaempferol, hyperin, myricetin, catechin, epicatechin, isoquercitrin, rutin Phenolic acids: Gallic acid, chlorogenic acid, caffeic acid, ferulic acid, ellagic acid Tannins: Various condensed and hydrolyzable tannins Triterpenoids: Betulinic acid, lupeol, ursolic acid Essential oils: β-caryophyllene, α-pinene, 1,8-cineole, limonene Polysaccharides: Water-soluble polysaccharides with antioxidant properties Meroterpenes: Guajadial, psidial A, psiguadial A and B Quercetin is identified as one of the most predominant and pharmacologically active flavonoids in guava leaves, exhibiting strong antidiarrheal, anti-inflammatory, and antioxidant activities.
Uses
Historically, herbalists and folk practitioners worldwide employed guava for a variety of ailments, most notably utilizing preparations of the leaves for gastrointestinal complaints such as diarrhea, stomach aches, and indigestion. Traditional practitioners also administered the plant for respiratory issues like coughs and sore throats, as well as for menstrual disorders and cramps.
In folk medicine, guava preparations were utilized for oral care, including toothaches, mouth ulcers, and gum irritation, while topical applications such as poultices were historically applied to wounds and eczema. Various traditions also recommended the plant for managing joint discomfort, rheumatism, fevers, elevated blood pressure, and blood sugar levels. Depending on the custom, different parts of the plant were traditionally prepared as decoctions, infusions, poultices, or chewed directly.
How Sold
Guava medicinal products are available in various forms: Fresh fruit and leaves Dried leaf powder Guava leaf tea bags Standardized leaf extracts in capsules Liquid extracts and tinctures Essential oils Topical creams and ointments Dietary supplements
Warning
General Safety: Guava fruit is generally safe when eaten as food. Guava leaf extract may be safe when used short-term as medicine, but may cause temporary nausea or stomach pain in some people. Pregnancy and breastfeeding: Guava is likely safe when eaten as food during pregnancy and breastfeeding. However, there isn’t enough reliable information about the safety of using guava as medicine during these periods.
Stay on the safe side and stick with food amounts. Diabetes: Guava might lower blood sugar. People with diabetes should monitor blood sugar carefully when using guava medicinally, as medication doses may need adjustment. Surgery: Guava might lower blood sugar and potentially increase bleeding risk. Stop using guava as medicine at least 2 weeks before scheduled surgery. Eczema: Guava leaf extract might make eczema worse due to skin-irritating compounds.
Use with caution if you have eczema. Drug interactions: Guava may interact with diabetes medications, potentially causing blood sugar to drop too low. Monitor blood sugar closely and consult healthcare providers about potential dose adjustments. Digestive effects: Due to high fiber content, consuming large amounts may cause digestive discomfort or constipation in some people.