Coconut water: Is it really "nature's sport drink"?

By Jennifer Koslo, MS, RD, CSSD, CPT

Coconut water is not new. The liquid inside young, green coconuts has long been enjoyed in tropical countries due to its availability, cultural traditions, and beliefs regarding its health benefits. But recently the drink has gone mainstream in the U.S. and can be found in colorful juice-box styles and in a variety of flavors in most supermarkets. Sales of coconut water in the U.S. have jumped in the last 5 years from about $4 million to $40 to $60 million dollars annually. Part of this increase can be attributed to A-list celebrity endorsers who have recently invested in Vita Coco®, and the investment of Pepsi in O.N.E.™1 But is this drink really “nature’s sports drink” and can it “promote smoother, more hydrated skin”? What are the facts behind the hype? As a skeptic of almost every new food or beverage that seems to have the makings of a fad, I thought I would do some research and decide for myself.

 Just the Nutrition Facts

Coconut water is not to be confused with coconut milk which is squeezed from the inside pulp and used as a common ingredient in many Thai recipes. Coconut water is from young, green coconuts and is low in calories and a natural source of electrolytes including sodium and potassium. Eight ounces of coconut water has 46 calories, 9 grams of carbohydrates, 250 mg of sodium, 600 mg of potassium, 60 mg of magnesium, 45 mg of phosphorus, and 2 grams of protein.2 The electrolyte content is more than double that of traditional sports drinks with about half of the carbohydrates. So, if you wash that bagel down with fresh coconut water after your workout then, yes, it can contribute to optimal hydration and recovery. In addition to electrolytes and carbohydrates, coconut water contains other beneficial components including vitamins, minerals, antioxidants, and amino acids.

Not so Fast!

The commercial brands sold in the U.S. (I looked at the nutrient data for 5 brands) have a potassium content that is similar to the water fresh from the fruit; however, the sodium content is much lower with an average of 35–60 mg per eight ounces. Compare this to Gatorade which contains 70 calories, 19 grams carbs, 154 mg sodium, and 42 mg potassium per serving and as a sports drink the sodium level in consumer coconut water is far too low for adequate electrolyte replacement.

Commercial coconut water brands versus traditional sports drink:

Product (per 8 ounces

Calories

Carbs (g)

Sodium (mg)

Potassium (mg)

Popular coconut waters:

Harvest Bay Original Coconut Water

47

12

25

480

Naked Juice Coconut Water

44

10

14

473

O.N.E. 100% Coconut Water

44

10

44

487

Vita Coco 100% Pure Coconut Water

44

10

29

494

Traditional sports drink:

Gatorade Thirst Quencher

50

14

110

30

I also researched the use of coconut water as a fluid replacement drink for physical activity and found two published studies. The first study compared rehydration after exercise with young coconut water, a carbohydrate electrolyte beverage, and plain water.3 The results indicated that recovery was similar when either coconut water or the carbohydrate electrolyte beverage was ingested. However, as stated previously, water straight from the nut has a higher sodium content then the commercial varieties sold in stores. The second study used a sodium enriched coconut water for testing rehydration4 and compared it to a sports drink and fresh coconut water from the nut. The results indicated that the sodium enriched coconut water was as effective as the sports drink in whole body rehydration.

Not All Bad News

Although coconut water may not beat traditional sports drinks at rehydration it can serve as a healthy alternative to soda and other sugary drinks. Most Americans fall short of their potassium requirements, an electrolyte that plays an important role in regulating blood pressure and muscle contractions. The Dietary Guidelines for Americans recommend that Americans follow a potassium rich diet by including adequate servings of fruits and vegetables. Despite this recommendation only 14 percent of adults and 9 percent of adolescents eat the recommended 5 servings of fruits and vegetables per day.5

Bottom Line

If you are looking for a low calorie refreshing beverage with a high amount of potassium, then this is your drink. But in terms of recovery from intense exercise lasting more than 60 minutes, I recommend sticking with traditional sports drinks. Through years of research, sports drinks are specifically formulated for athletes with the amount of electrolytes and carbohydrates at the levels found to promote optimal hydration. Drinks like Gatorade contain 4–8 percent carbohydrate concentration (10-18 grams per 8-ounce serving), around 100 mg of sodium, and 30 mg of potassium. This formula has been shown to promote fluid absorption from the intestines and encourage fluid retention in order to prevent dehydration and prolong exercise.

Coconut water is a nutritious potassium rich drink and can fit into a balanced diet as a low sugar alternative for hydration. What about the promise of “smoother, more hydrated skin”?  Well you will have to test that out for yourself.


References

1. ABC News. M. Locke, Coconut Water Aims to Crack Sports Drink Market. Retrieved from http://abcnews.go.com/Entertainment/wirestory?id=10170765&page=2 (accessed August 2010).
2. USDA NutrientData, Nuts, Coconut Water (liquid from coconuts). Retrieved from http://www.nutritiondata.com/facts/nut-and-seed-products/3115/2 (accessed August 2010).

3. I. Ismail, R. Singh, and RG. Sirisinghe, RG, “Rehydration With Sodium-Enriched Coconut Water After Exercise-Induced Dehydration,”  Southeast Asian Journal of Tropical Medicine Public Health, 38 no. 4 (2007).
4. M. Saat, R. Singh, R. Sirisinghe, and M. Nawawi, “Rehydration After Exercise With Fresh Coconut Water, Carbohydrate-Electrolyte Beverage and Plain Water, “Journal of Physiological Anthropology and Applied Human Science, 21 no. 2 (2002).
5. Centers for Disease Control and Prevention, National Health and Examination Survey Data. Retrieved from http://www.cdc.gov/nutrition/professionals/data/index.html (accessed August 2010).


Jennifer Koslo, PhD, RD, CSSD, CP

Jennifer Koslo is a full-time faculty member with Kaplan University’s School of Health Sciences and teaches courses such as Vitamins, Herbs, and Nutritional Supplements, Sports Nutrition, and Contemporary Diet and Nutrition.  Ms. Koslo is a Registered Dietitian (RD) and one of the few Certified Specialists in Sports Dietetics (CSSD) in the country.  In addition to teaching online, Ms. Koslo is a sports nutrition consultant on a private consultation basis.

Ms. Koslo received her Bachelor of Science in Biology from Juniata College, and earned a dual Master of Science in Human Nutrition and Exercise Science from Colorado State University. She earned her Registered Dietitian certification from the American Dietetic Association (ADA) and Colorado State University, and is a Certified Specialist in Sports Dietetics certification from the ADA. She also holds a PhD in Education with an emphasis in instructional design for online learning from Capella University.

In addition to serving in the US Peace Corps in Sierra Leone, West Africa, for 2-1/2 years, Ms. Koslo also worked as a cardiac rehabilitation dietitian, and at the Arizona Department of Health Services as the chronic disease nutritionist.  She is also an American Council on Exercise Certified Personal Trainer. 

Kaplan Higher Education Corporation is a division of Kaplan, Inc., a subsidiary of The Washington Post Company.

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