King coconut is a type of coconut fruit cultivated in Sri Lanka where it is known as Thembili. It is sweeter than regular coconuts. There are several varieties of "Thembili" as "Tembili", "Ran Thembili"(රන් තැබිලි), "Gon Thembili"(ගොන් තැබිලි) etc.
King coconut is short in stature and commonly found in Sri Lanka, and the nuts of which Sri Lankans regard as a "living pharmacy" is the most versatile and medically practical form of the coconut plant available. Sri Lankans sell and consume thousands of them on a daily basis.
In almost every Sri Lankan home irrespective of class, a king coconut palm is a common sight. Another familiar sight are the bunches of king coconuts displayed for sale in many wayside kiosk throughout the country.
These nuts come in many varieties, the most commonly found being the "red dwarf" (kaha thambili, commonly referred to as gon thambili). The other variety is "ran thambili", a smaller variety containing about forty nuts in a bunch.
"Kurumba", the green coloured young coconut that is easily available in the villages is cheap and popular.
Compared to the aerated waters that are usually artificially coloured and flavoured, the natural coconut drink refreshes and purifies the body. In many Sri Lankan ayurvedic remedies the king coconut has been prescribed to cure many ailments related to impurities in the system.
The king coconut is a well-known source of carbohydrates, vitamin E, iron, calcium and phosphorus. It also has a high dietary soluble fibre and appreciable amounts of protein and fat.
King coconut water has been used from time immemorial as an ayurvedic cure. One of the most common cures is a mixture of "aralu" powder (myrobalan) added to the water of one king coconut. This concoction acts as a very effective laxative.
This "aralu brew" according to Sri Lankan ayurvedic practitioners (also known as veda mahattayas) has the necessary properties to "expel heat from the body" therefore resulting in a feeling of freshness. This feeling of freshness according to the veda mahattayas is due to the brew’s ability to balance the body’s electrolytes.
The water of the king coconut is naturally sterile and therefore it is a good substitute for saline. In World War 2 both American and Japanese military doctors injected king coconut water into a patient’s veins instead of sterile glucose solutions.
Countries like India, Malaysia, Indonesia, Fiji and the Philippines have started to popularise the use of this all-purpose-wonder "drug" and have now started to process and preserve it for export.
Sri Lanka has now started to package the palatable coconut water into tetra packs that are being exported. Coconut water has a nutritive energy value of 17.4 calories per 100 gm and 0.1 g protein, 0.1 g fat, 4 g carbohydrates, 0.02 mg calcium, 0.01 mg phosphorus and 0.5 mg iron.
Dr. D. P. Atukorale, the well known cardiologist, has stated that tender coconut water has the medical capability of being used to feed infants suffering from intestinal disturbances, oral rehydration, to keep the body cool, to apply on the body to prevent prickly heat and summer boils and also treat the rashes caused by small pox, chicken pox and measles. He says it’s a good tonic for the old and the sick.
It also increases the flow of urine and can be used as a blood plasma substitute because it is sterile, pyrogen—free and does not destroy blood cells. It also contains organic compounds that have growth promoting properties. According to Dr. Atukorale ayurvedic concepts believe that "it is unctuous, sweet, increasing semen, promoting digestion and clearing the urinary path".
However, the doctor also added a word of warning stating that if tender coconut water were to be injected intravenously, it would cause hyperkalaemia (high level of serum potassium) in patients with poor kidney function because it contains a high potassium level of 290 mp%.
Therefore with this word of warning in mind it is best to remember that tender coconut water is best avoided in cases of hyperkalaemia such as renal failure, acute adrenal insufficiency and in patients with low urine output due to haemolysis following blood transfusions and also in cases of viper bite victims because the serum potassium level is very high.