This year’s summer drink for health-conscious celebrities appears to be coconut water. Madonna, Demi Moore, Kim Kardashian, Molly Sims, Heidi Klum, and Brooke Shields have all been spotted sipping the beverage. Madonna has even invested over a million dollars in Vita Coca, one of the brands of the drink. It is estimated that the coconut water market is now at $50 million and climbing. Even Coca-Cola and Pepsi are getting into this market.
What is coconut water, and why might celebrities be flocking to it?
Coconut water is the clear liquid inside young coconuts. As the fruit matures, the coconut water gradually is replaced by the coconut meat and air. It is different than coconut milk, which is a mixture of water and pulped coconut meat. Coconut water has been a popular drink in the tropics, where it has been served fresh, canned, or bottled for many years.
There it’s been served with the outer husk of the coconut removed and a hole cut into the top for access to the water. In this country, it is found packaged under the brand names O.N.E., VitaCoco, and ZICO. Ten years ago, the United Nations' Food and Agricultural Organization (FAO) was granted a patent -- the first ever to a U.N. agency -- for bottling coconut water in a way that preserves its nutrients.1
There it’s been served with the outer husk of the coconut removed and a hole cut into the top for access to the water. In this country, it is found packaged under the brand names O.N.E., VitaCoco, and ZICO. Ten years ago, the United Nations' Food and Agricultural Organization (FAO) was granted a patent -- the first ever to a U.N. agency -- for bottling coconut water in a way that preserves its nutrients.1The mineral composition of coconut water resembles that of intracellular electrolytes and was used as intravenous therapy in 12 pediatric patients in Cuba in 1942.2 It is believed that both the Japanese and British used coconut water intravenously in World War II.
The Intravenous use of coconut water was studied by Eiseman and colleagues in a series of 157 patients in 1954.3 Although no toxicity or allergic reactions were observed, it did cause diuresis and Eiseman et al. concluded that it was of no clinical value for rehydration, but might be useful (after adding sodium salts) for the emergency treatment of hypovolemia when other sterile, pyrogen-free fluids are unavailable. A more recent case documented the successful use of coconut water as a short-term intravenous hydration fluid in a Solomon Island patient.4
Coconut water has been proposed as an oral rehydration fluid for patients with diarrhea in underdeveloped countries5 but the great variability in chemical composition during maturation of the fruit makes its use for this purpose problematic.6 Sodium-enriched, fresh, young coconut water is "as good as ingesting a commercial sports drink for whole body rehydration after exercise-induced dehydration but with better fluid tolerance."7
The Intravenous use of coconut water was studied by Eiseman and colleagues in a series of 157 patients in 1954.3 Although no toxicity or allergic reactions were observed, it did cause diuresis and Eiseman et al. concluded that it was of no clinical value for rehydration, but might be useful (after adding sodium salts) for the emergency treatment of hypovolemia when other sterile, pyrogen-free fluids are unavailable. A more recent case documented the successful use of coconut water as a short-term intravenous hydration fluid in a Solomon Island patient.4
Coconut water has been proposed as an oral rehydration fluid for patients with diarrhea in underdeveloped countries5 but the great variability in chemical composition during maturation of the fruit makes its use for this purpose problematic.6 Sodium-enriched, fresh, young coconut water is "as good as ingesting a commercial sports drink for whole body rehydration after exercise-induced dehydration but with better fluid tolerance."7
So much for the science. What about the hype? The web site for the Vita Coco brand of coconut water claims that their product is "super-hydrating," "Life-enhancing" and "Immunity boosting" without providing any evidence at all for these assertions. The O.N.E. web site, in a section called "Health Facts," makes the following claims:
- Coconut water is effective in dissolving kidney stones. "A coconut a day keeps the urologist away." They cite a single 33-year-old study8 that has not been reproduced.
- Coconut water is a "natural alternative to Viagra" because it "stimulates and strengthens reproductive functions, especially in men. In a medical study, women in their mid-sixties reported an increase in their libido after drinking coconut water." No such medical study exists. The reference given is to pp.146-147 of a 2005 book by Bruce Fine, entitled Coconut Cures, which contains nothing more than several unsupported assertions about the "reputed" effects of coconut water on libido and virility.
The basis for other health claims (such as a hangover cure9) derive from the facts that coconut water has no fat or cholesterol (it’s the coconut meat, which develops later, that has the oil), is low in sugar and contains more potassium than a banana. It also contains small amounts of calcium, phosphorus and magnesium. But once exposed to air, the liquid rapidly loses most of its nutritional characteristics, and begins to ferment. Most manufacturers use a process called “flash pasteurization” to preserve nutrients while eliminating possible contaminants.
When evaluating the health claims for coconut water, kombucha tea, or any similar natural product, be sure you have your close at hand.
References
1.
2. Goldsmith, H.S. (1962) . British Journal of Surgery, pp.42-422
3. Eiseman, B., Lozano, R.E. and Hager, T. (1954) . AMA Archives of Surgery, pp.87-93.
4. Campbell-Falk, D et al. . Am J Emerg Med 2000 Jan;18(1):108-11
3. Eiseman, B., Lozano, R.E. and Hager, T. (1954) . AMA Archives of Surgery, pp.87-93.
4. Campbell-Falk, D et al. . Am J Emerg Med 2000 Jan;18(1):108-11
5. Kuberski T. et al. . N Z Med J. 1979 Aug 8;90(641):98-100 http://www.ncbi.nlm.nih.gov/pubmed/290921
6. Fagundes Neto U. et al. . J Am Coll Nutr. 1993 Apr;12(2):190-3 Note: Be sure to check the "Nutrition Facts" labels on commercial products. We have observed significant variations in their nutrient concentrations.
7. Ismail I et al. . Southeast Asian J Trop Med Public Health. 2007 Jul;38(4):769-85
8. Macalalag EV Jr., Macalalag AL. . Int Surg. 1987 Oct-Dec;72(4):247
8. Macalalag EV Jr., Macalalag AL. . Int Surg. 1987 Oct-Dec;72(4):247
9. Duerr C. Coconut Water: . Time. May 31, 2010.