Guava (Psidium guajava L.), native to Central America, belongs to the Myrtaceae family. It is a small tree that grows between 3m and 6m tall. The fruit is large, with a variety known as ‘xá lị’ which can weigh up to 930 grams, featuring white or slightly pink flesh when ripe.
In our country, there are also smaller guava varieties such as ornamental guava (P. cujavillus Burnf.) with fruit sizes ranging from 2cm to 3.5cm, pink flesh, and many seeds, and the coastal guava (P. littorale Raddi.), which has small, round fruit measuring 2.3cm to 3cm, with strawberry-like flesh and small seeds…
The guava fruit is considered a nutritious food that is low in calories (making it suitable for those looking to lose weight), and it serves as a source of vitamins A and C. Most of the vitamins are concentrated in the flesh close to the thin outer skin of the fruit. Guava can be eaten fresh or used to make cakes, ice cream, beverages, and jelly.
On the effectiveness of treating diarrhea, guava leaves have been recognized in numerous clinical and pharmacological studies. Guava leaves are officially listed in the Dutch Pharmacopoeia for use as a diarrhea treatment.
– In a clinical study involving 62 children with diarrhea caused by viral infection (rotaviral enteritis), the healing time recorded was 3 days (87.1%), which showed a significant reduction compared to the control group.
– A study in Brazil noted that a dosage of 8 micrograms/ml of guava leaf extract demonstrated activity against simian rotavirus, which causes diarrhea (82.2%).
– A study in Thailand, utilizing guava leaf powder to treat 122 diarrhea cases, yielded results equivalent to tetracycline at the same dosage (500 mg).
On the effectiveness for intestinal diseases, flavonoids such as quercetin in guava leaves affect acetylcholine secretion in the intestines, stimulating smooth intestinal muscles to alleviate abdominal pain caused by intestinal spasms. Additionally, guava leaves influence water reabsorption in the intestines. Lectins in guava leaves can bind to E. coli (a common bacteria causing diarrhea), preventing the bacteria from adhering to the intestinal wall and consequently preventing intestinal infections.
On the antibiotic, antiviral, and antifungal properties, laboratory tests have shown that extracts from guava leaves and stems are effective against bacteria such as Staphylococcus, Shigella, Salmonella, Bacillus, E. coli, Clostridium, and Pseudomonas…
– An extract from guava leaves using a 1:40 saline solution effectively kills Staphylococcus aureus.
– Fresh juice from guava leaves at a concentration of 66% exhibits activity against the Tobacco mosaic virus.
– Extracts from guava leaves inhibit the growth of fungi such as Trichophyton rubrum, T. mentagrophytes, and Microsporum gypseum…
A study in Jordan noted the effect of preventing acne caused by Propionibacterium acnes: Although not as effective as the antibiotics doxycycline and clindamycin, it can be effective in cases of antibiotic-resistant acne or when antibiotics cannot be used.
On cardiovascular effects, a study in Brazil reported that guava leaf extracts have various activities on the cardiovascular system and are effective in treating arrhythmias. Guava leaves also provide antioxidant benefits that protect the heart and improve heart function.
On hypoglycemic effects:
– A study in South Korea noted the inhibition of protein tyrosine phosphatase 1B by guava leaf extracts. This activity suggests that guava leaf water tested on rats has an effect on treating type 2 diabetes.
– In a study in Taiwan on rats, fresh guava juice administered intraperitoneally at a dose of 1g/kg helped lower blood sugar levels induced by alloxan, indicating that eating fresh guava may be beneficial for diabetic individuals.
– Some researchers concluded that fresh guava, containing high levels of soluble (pectin) and insoluble fiber, can help reduce blood sugar levels safely…
