By Dr. D. P. Atukorale
The water of fresh tender coconut (king coconut or "Thembili" and "Weware") which is the liquid endosperm is the most nutritious wholesome beverage that the nature has provided for the people of the tropics to fight the sultry heat. It has a caloric value of 17.4 per 100 gm.

According to Ayurveda "it is unctous, sweet, increasing semen, promoting digestion and clearing the urinary path".

Medicinal Properties of Tender Coconut Water (T.C.W.)

Some of the medicinal properties of T.C.W. reported are:

1. Good for feeding infants suffering from intestinal disturbances

2. Oral rehydration medium.

3. Contains organic compounds containing growth promoting properties.

4. Keeps the body cool.

5. Application on the body prevents prickly heat and summer boils and subsides the rashes caused by small pox, chicken pox and measles etc.

6. Presence of saline and albumin makes it a good drink in cholera cases.

7. Excellent tonic for the old and the sick.

8. Diuretic (a substance which tends to increase flow of urine).

9. Can be injected intravenously in emergency cases such as cholera and dysentery when other pyrogen-free fluids are not available.

10. Can be used as a blood plasma substitute because it is sterile, pyrogen - free and does not produce heart and does not destroy blood cells.

11. Aids the quick absorption of drugs and make their peak concentration in the blood easier by its electrolyte effect.

12. Urinary antiseptic and eliminates poisons in case of mineral poisoning.

"Fluid of Life"

Tender coconut water is the natural isotonic beverage with almost the same level of electrolyte balance as we have in our blood. It is the "fluid of life" says Mr. Morton Satin, Chief of FAO’s Agricultural and Post Harvest Management Service.

A word of warning

When T.C.W. is injected intravenously, in view of its high potassium level (290 mp%) it may cause hyperkalaemia (high level of serum potassium) in patients with poor kidney function.

In cases of patients with dysentery and cholera and other types of severe diarrhoea, in whom, serum potassium level may be low, T.C.W can be used both orally and intravenously. T.C.W. has been used intravenously to treat diarrhoea both in Sri Lanka and abroad by various researchers.

As mentioned earlier, T.C.W. is best avoided in patients with hyperkalaemia such as renal failure, acute adrenal insufficiency and in patients with low urine output due to haemolysis following blood transfusions and in case of viper bite in whom serum potassium is usually very high.

Use of i.v. Tender Coconut Water In the Treatment of Diarrhoea

Prof. K Rajasuriya and Colleagues were the first to use i.v. T.C.W. to treat diarrhoea in Sri Lanka (CMJ, Vol. 2, 1954, 255-261) Prof. C. C. de Silva used intravenous T.C.W. in the treatment of infantile diarrhoea (Paediatric International Rome, 19, 1958, 225) Dr. (Mrs.) N. P. Fernando used T.C.W. as i.v. rehydrating fluid in malnourished children with diarrhoea (J.C.H., Vol. 4,1955, 57-59).

Tender coconut water has been used in other areas of the world where intravenous solution, cannot be obtained. Japanese have used T.C.W. intravenously in Sumatra in World War I. Pradera et al have used intravenous T.C.W. for paediatric patients in Havana, Cuba without any serious reactions (Am. J. Dis. Child, 64, 1942, 977). Dr. Ben Eisman at Barnes Hospital, St. Louis used fresh intravenous T.C.W. in 21 patients without evidence of any serious reactions (B. Eisman, A. M. A. Archives of Surgery, 68, 1954, 167).

Composition of Fresh Tender Coconut Water

Sugars in the form of glucose and fructose form an important constituent of T.C.W. The concentration of sugar steadily increases from 1.5% to about 5.5% in the early months of maturation and this slowly falls to about 2% at the stage of full maturity. Sucrose which is a non-reducing sugar, appears in the late stages and this increases with maturity. So tender king coconut water and "Wewara" water do not contain significant amounts of sucrose 90% of total sugar in mature coconut is sucrose and hence the different taste of mature coconut water.

Minerals

Tender coconut water contains most of the minerals such as potassium (290 mg%), Sodium (42 mg%), Calcium (44 mg%), magnesium (10 mg%), Posphorus (9.2 mg%), iron 106 mg%), and copper (26 mg%) (Source: Satyavate Krishnankutty, 1987).

T.C.W. also contains traces of sulphur and chlorides. Among the minerals, more than half is Potasium and the concentration is influenced by potash manuring. In view of the high level of potassium and other minerals, T.C.W. plays a major role in increasing the urinary output. (Keith et al (Archives of Internal Medicine, 71, 1943,675) and Platt (Clinical science, vol. 9, 1950, 369) have shown that in dehydrated patients treated with excess of potassium, the potassium clearance is greater as there is tubular excretion of potassium in addition to glomerular filtration.

T.C.W. also contains small amounts of protein. The percentages of arginine. Alanine, cystine and serene in T.C.W. are higher than those in cow’s milk. Since T.C.W. does not contain any complex protein, the danger of producing shock to the patient when given i.v. is minized. According to Pradera, T.C.W. protein is in the form of peptones or acid metaprotein and has no sensitizing properties in animals or man.

Amino-Acid Composition of Tender Coconut Water

Percentage of total protein is as follows: Alanine is 2.41, arginine 10.75, aspartic acid 3.60, cystine 0.97 to 1.17, glutamic acid 9.71 to 14.5, histidine 1.95 - 2.05, leucine 1.95 - 4.57, proline 1.21 - 4.12, phenylalamine 1.23, serene 0.59 - 0.91, tyrosine 2.83 - 3.00. (Source Pradera et al Am J. Dis. Child, 64, 1942, 977).

Vitamins in Tender Coconut Water

T.C.W. is not a good source of vitamins and contains both ascorbic acid (vit C) and vitamin B group and contains 0.64 micrograms per ml of nicotinic acid, 0.52 of pantothenic acid 0.02 of biotin, less than 0.003 micrograms of folic acid, traces of thiamine and pyridoxine (Source: The Wealth of India 1950).

Fat Content of Tender Coconut Water

The fat content of T.C.W. increases with ripening. Unripe fruit contains as little as 0.084g per 100C.C. This increases with maturity. For i.v. infusions unripe and tender fruits have been used.

To conclude, fluid from unripe coconut is sterile, pyrogen-free and non-haemolytic. It’s carbohydrate content is suitable for human intravenous use. The electolyte pattern resembles that of intracellular fluid. It’s high potassium concentration poses a potential hazard in patients with hyperkalaemia and those with poor kidney function. It is possible that the high concentration of calcium and magnesium found in T.C.W. may increase the body tolerance to high potassium level.

In underdeveloped parts of the world where it is impossible to prepare pure intravenous solutions, tender coconut water is an easily obtainable source of sterile pyrogen-free i.v. fluid.