Guava is one of the best gifts presented by nature, according to a Korean company producing health and beauty products. I couldn't agree more. The US Department of Agriculture's handbook No8, which details the composition of foods, says the fruit is rich in vitamins A and B, calcium and iron, and contains five times more vitamin C than oranges, five times more fibre than apples, and more potassium than bananas. But there is one other reason why I think every backyard should have a guava tree: It is medicinal.
every backyard should have a guava tree, not just for its fruit but also for its leaves.
When I was young, my mother would boil guava leaves and mix the decoction with my bathwater after I had recovered from an illness. This, she told me, would eliminate toxins from the body and hasten recovery. I know someone who believes his peptic ulcer was cured by drinking a decoction of the leaves, which is also a good diuretic for those who have kidney trouble. The decoction is also great as a gargle for those with mouth ulcers, and as a foot bath for those suffering from athlete's foot. The decoction is also used as a wash for eczema and ulcers, and as a remedy for gastroenteritis and chronic diarrhoea. A poultice made from young leaves and shoots heals wounds and cuts. For internal use, the dose is 30g to 60g for one litre of water, four to five cups a day.
Who needs herbal remedies in this age of modern medicine, you might ask. Used over a long period of time, modern medicines can be addictive or have serious consequences on the liver. Medicinal plants, on the other hand, rarely have any harmful effects in the body even when one takes a cup or two more than the amount suggested. My brother-in-law who had a peptic ulcer took chemical remedies but found no relief, and turned to the guava leaves in case the decoction could help. According to him, it did.
Korean researchers found that guava leaves contained three insulin-like compounds which effectively reduced the blood sugar level of insulin-dependent diabetic animals. In collaboration with the International University of Korea, a Korean company developed a tea product which it claims to be anti-diabetic. But why buy guava tea from Korea when Thailand is one of the leading producers of guava in the region?
Of all fruits, guava ranks as one of the best sources of vitamin C.
If you have a tree, you can just pick and dry some leaves and make your own tea. To be effective, the leaves must be fully developed, neither too mature nor too young. Dry thoroughly, then grind until fine. Pour boiling water, steep for 15 minutes, and strain. This can be used as a healthful and harmless substitute for commercial tea imported from Sri Lanka, India or China.
Analysis by the food laboratory of Kochi Women's University in Japan found guava tea to contain a high level of polyphenols, a type of antioxidant which increases immunity and helps prevent diseases. Specifically, it prevents cardiovascular diseases, hypertension and obesity, and suppresses cancer. Tests conducted by the Yakult Central Research Institute in Japan on 19 people aged 40 and above with mild obesity found that their blood sugar content dropped by 8-10% 30 minutes after drinking guava tea.
The same analysis also found that 100g of dried guava leaves contained 327-729.2mg of phosphorous, 186.7-257.9mg of magnesium, 136.4-257.9mg of calcium, 132.5-263.3mg of sodium and 112.9-164.7mg of potassium. Its iron content was higher than that of the fresh fruit, 8.7-18.5mg compared to the fruit's 0.36-2.49mg, but contained little vitamin C, 11.4-33.3mg, compared to the fruit's 117.9-301.6mg.
The Korean company which came up with the guava tea now also produces pills from the fruit and a line of beauty products including shampoo, body wash, soap, skin lotion and moisturiser. Apparently, the fruit is not only good for the health but good for the skin as well. But why buy a bottle of guava pills containing 500g total of the leaves for US$60 (1,800 baht) when in Thailand you can eat fresh fruit for 30 baht a kilogramme?
A member of the Myrtaceae family of plants which also includes the roseapple, Psidium guajava is believed to have originated in the American tropics between Mexico and Peru. The Spaniards took it across the Pacific to the Philippines and the Portuguese introduced it to India. It is now widely distributed throughout the tropics and subtropics, but the guava widely grown in Thailand with big fruit was brought into the country from Vietnam, hence it is called farang Vietnam, or Vietnamese guava. Thailand now grows a new and improved variety with few seeds.
Grafted saplings which bear fruit in just two years are available at plant fairs, like the agricultural fair being held annually at Kasetsart University during the first week of February. Like all fruit trees, it needs full sun and soil with good drainage. As flowering takes place on newly emerging shoots, frequent light pruning and regular watering will promote continuity of production throughout the year. From flowering to harvest, the fruit takes 14-20 weeks to develop, depending on the cultivar. After harvest apply fertiliser around the base of the tree, and supplement this with a top dressing of decomposed animal manure. Alternatively, you may apply small doses of fertiliser every month or two.
Guava is susceptible to fruit fly attack when allowed to ripen on the tree, hence commercial growers wrap the fruit to prevent it from insect attack. It is ready for harvest when the colour has turned from dark to light green with the first sign of yellowing.
The fruit's nutritive value is at its highest when it is eaten fresh before it becomes fully ripe.
About the author
- Writer: Normita Thongtham