Coconut Water: King of Beverages?

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Regular readers will know our aim is to equip you with reliable information on health trends that will help you make empowered decisions about your health… and to do so in a timely manner. To that end, here we examine the properties of one of the most popular beverages of the last decade or more: coconut water. Joking aside, it has been taken for granted as a super healthy beverage and regularly consumed by many for some time now… but the body of evidence is actually still in its infancy. How well do we know the facts?

Key Points:

  1. Coconut water is a source of various micronutrients, including a good source of electrolytes
  2. Despite claims of some superior power, coconut water is only about as hydrating as water or sports drinks. It is potentially lethal if used to rehydrate from severe diarrhoea, or by people with kidney disease, uncontrolled type 1 diabetes and some other conditions, or people using certain medications.
  3. There is weak evidence that it may protect your cardiovascular system, reduce the impact of diabetes, be anti-inflammatory, and possibly anti-clotting, anti-cancer, skin and neural protecting properties, among others.
  4. The nutritional and nutraceutical value of the beverage varies widely according to type of coconut, maturity, processing and storage.

Coconut water basics: nutritional properties and chemical composition

Coconut water is the clear liquid that comes from the centre of a coconut. Not to be confused with coconut milk, which is the white meat pulverished into this water. It is slightly acidic, and sterile- which means drinking it straight from the coconut shouldn’t pose a problem even in medical situations. 

It’s important to note that its composition varies depending on the type of coconut… and also with processing and storage methods, and changes as the coconut matures (see more about this below). For example, the quantity of salicylic acid and antioxidants decreases… Young coconuts are green and generally classified as those that are six-seven months old; mature ones are one year old. 

It’s hardly surprising that coconut water has numerous biologically active bits, given it comes from a plant. These include the amino acid arginine, vitamin C, several minerals, including decent amounts of calcium, magnesium, potassium and selenium, and small amounts of the B-group vitamins that are essential as coenzymes to many cellular reactions. You can see specific nutrition data in the table below. Keep in mind that these values may not be representative of all coconut water products.

Although the figures in this table look pretty precise, they can’t be relied upon as so, as the values differ according to the source… this can be related to both the product being tested and the testing procedures.

Nutrition information table (click to see)

Component Young coconut waterMature coconut water
Proximatesg/100g% NRVg/100g% NRV
Protein0.12<1%0.52≤1%
Total Fat0.7n/a0.12n/a
Total Carbohydrate4.76n/a4.41n/a
Total sugars5.43n/a3.42n/a
Sucrose0.06n/a0.51n/a
Glucose2.61n/a1.48n/a
Fructose2.55n/a1.43n/a
Dietary FibreNone detected0%None detected0%
Mineralsmg per 100g (*or as otherwise stated)% NRVmg per 100g(* as otherwise stated with)% NRV
Calcium27.352.1-2.7%31.642.4-3.2%
Iron0.020.1-0.25%0.020.1-0.25%
Magnesium6.401.5-2.19.442.2-3%
Phosphorous4.660.5%12.771.3%
Potassium203.705.4%-7.3%257.526.8-9.2%
Selenium *1µ/100mL1.4-1.7%1µ/100mL1.4-1.7%
Sodium1.750.2-0.4%16.101.75-8%
Zinc0.070.5-0.9%0.020.1-2.5%
Copper0.010.6-0.8%0.031.7-2.5%
Manganese0.122.2-2.4%0.081.5-1.6%
Aluminium0.07n/a0.06n/a
Boron0.05n/a0.08n/a
Vitaminsmicrog per litre (* or as otherwise stated)% NRVmicrog per litre(* or as otherwise stated)% NRV
Vitamin C74.10.2%70.80.2%
Thiamin (B1)*0.01mg/100mL0.8-0.9%0.02mg/mL1.6-1.8%
Riboflavin (B2)0.1<0.1%0.1<0.1%
Niacin (B3) derived equivalents*0.11mg/100mL0.7-0.8%0.16mg/mL1-1.1%
Pyridoxine (B6)*0.03mg/100mL1.8-2.3%0.03mg/100mL1.8-2.3%
Folate (B9)*3µg/100mL0.75%3µg/100mL0.75%
Data adapted from Rao, S. S., and Najam, R. (2016). Coconut water of different maturity stages ameliorates inflammatory processes in model of inflammation. Journal of intercultural ethnopharmacology, 5(3), 244–249. https://doi.org/10.5455/jice.20160402120142.

EXCEPT in the case of nutrients marked ‘*’, which was obtained from FSZANZ, the Australian Food Composition Database-  Release 1.0 .F002986: Coconut, fresh, young or immature, water or juice. https://www.foodstandards.gov.au/science/monitoringnutrients/afcd/Pages/fooddetails.aspx?PFKID=F002986, and  F002984: Coconut, fresh, mature, water or juice. https://www.foodstandards.gov.au/science/monitoringnutrients/afcd/Pages/fooddetails.aspx?PFKID=F002984
% NRV values calculated based on NRV’s for adults who are neither pregnant nor lactating. National Health and Medical Research Council and Ministry of Health. (22 September, 2017). Nutrient Reference Values for Australia and New Zealand. https://www.nrv.gov.au/node/3

Not just nutritious- nutraceutical-ous…?

Let’s dissect the facts relating to some of the special health and medicinal benefits that have been attributed to coconut water…

Does coconut water have super rehydrating power?

No.

Oh, you want more detail? Well, this claim seems reasonable seeing as the bev sure tastes and feels refreshing… and it contains electrolytes that are key to rehydration. In fact, there have even been reported cases where it’s been used for short term IV rehydration- as far as I know this has only happened in remote regions where standard IV fluids are unavailable though.

Hold on though- the electrolyte composition of coconut water is unbalanced (i.e. out of sync with the blood)… it contains magnesium and calcium, but is particularly high in potassium while being low in sodium. (The potassium:sodium ratio is approximately 2:1). Excessive potassium in the blood can actually be life threatening, wreaking havoc with your heart. So young coconut water can be used in the beginnings of mild diarrhoea (i.e. when moderate amounts are used to rehydrate). BUT neither young nor mature varieties should be used when diarrhoea or dehydration is severe, or if you have kidney disease or uncontrolled type 1 diabetes among other conditions, are using some medications (consult your doctor). 
When it comes to recovering from dehydrating exercise, young coconut water is about as useful as good ol’ water or a carbohydrate-electrolyte sports drink. Albeit this evidence came from a small study of  only eight people. One potential advantage is that it may be better tolerated than these other options. More research should be conducted to back up such subjective reports. It’d also be worth examining the value of coconut water with added sodium.

As you’ll see below, though, there are also cases where coconut water seems to have a diuretic effect.

Does coconut water protect your heart?

Leaving aside the risk of consuming too much potassium if you are at risk or drink excessive amounts, there is some evidence of a positive effect cardiovascular risk factors and markers. However, more robust human evidence is required.

According to rat studies anyway, coconut water (whether young or mature) improves cholesterol. That is, when rats were given cholesterol-enriched feed, coconut water lowered LDL-cholesterol and triglycerides, and increased HDL-cholesterol. In fact, it was seen to basically be as effective as the medication lovastatin.

Some other unfortunate rats were given induced heart attacks. Those that were also fed young coconut water displayed lower activities of several enzymes that can mark damage to the heart muscle. (If you want to know specifics, these were creatine phosphokinase, serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase and lactate dehydrogenase). 


There is also some suggestion that some people with high blood pressure may benefit from regularly drinking coconut water. For once we have human evidence for this- albeit from small studies. In one, 71% of hypertension sufferers drinking coconut water saw some drop in their systolic blood pressure. There is suggestion that it may achieve this through diuretic effects (people have reported they urinate more), or by increasing blood potassium levels.

Can coconut water contribute to diabetes management?

Maybe, if you ask yet another group of rats. They were given diabetes by way of the drug alloxan. Those receiving coconut water for 45 days had improved blood glucose and insulin levels. Furthermore, enzymes that metabolise carbohydrate became more active, more glycogen was stored in the liver (a process that reflects insulin sensitivity). Perhaps most impressively, the damage caused to the pancreas by alloxan was reduced, and regeneration of the pancreatic cells that synthesise and release insulin was observable.

Does coconut water have anti-inflammatory effects?

You guessed it… we turn to more rats to give us an inkling on this. They had inflammation (in the form of paw oedema) induced, and this was combated by coconut water. 

Assuming we humans can also experience anti-inflammatory effects, the question is how? Well, Coconut water has an unique composition including flavonoids and micronutrients with antioxidant potential- for example kinetin, which in cell cultures has been seen to protect proteins and DNA from the calf thymus (see more about this molecule below). It contains abscisic acid which inhibits inflammation and also has antihistaminic effects. It may  also have something to do with salicylic acid, a component that gives aspirin its anti-inflammatory effects.

The authors of the rat study noted that the anti-inflammatory effect was stronger when young coconuts are used; and there is more salicylic acid present in young vs mature coconuts. Unfortunately the antioxidant content  decreases as the coconut matures.

Miscellaneous benefits from phytohormones

Coconut water is home to a lot of plant hormones, including kinetin,  trans-zeatin and their derivatives (all belong to the cytokinin class of phytohormones). 

Kinetin and derivatives

In cell culture studies (and fruit flies), kinetin and derivatives have been seen to have anti-ageing effects eg: in skin cells and cells which line blood vessels. If this is in time proven to be true in human clinical trials, kinetin will join phytoestrogen in the ranks of skin-supporting phytohormones. 

Thanks to cell culture studies it’s also been (prematurely) spruiked as a potential means of preventing blood clots (through anti-platelet effects) and possibly inhibiting growth or being toxic to some types of tumours. If these were true on a clinical level, questions would remain regarding dosage required vs that provided by coconut water. 

Trans-zeatin and derivatives

Recent evidence suggests trans-zeatin inhibits the breakdown of the key parasympathetic nervous system neurotransmitter, acetylcholine. That is to say, it can safeguard the sending of neural messages. Because of this, some researchers have indicated it can be used to treat conditions such as Alzheimer’s disease and dementia. Furthermore, it also seems to prevent the formation of amyloid β-proteins, which contribute to Alzheimer’s disease. 

Also, just like kinetin, cell culture studies suggest it can have anti-ageing effects on skin and may have anti-tumour activity. These may be worth exploring in clinical studies. 

What makes the best coconut water?

The best option would be drinking straight from a young, green coconut that has recently been taken from a tree. When that is not an option, i.e. for all of us who don’t live in the tropics, there’s a few factors to take into account.

The composition will vary according to depending on the variety of coconut used, production methods and storage. Pasteurisation is often used as it’s a  useful preservation method. Unfortunately the heat speeds up the degradation of antioxidants and other nutrients. Contact with air and exposure to acids or alkaline also increases degradation.

Young coconuts are reportedly used, and as you may have picked up they appear preferable for health reasons. However, environmentally speaking, such harvesting is considered premature and not sustainable. Which puts us in a bit of a quandary.

The Verdict

We don’t yet have the evidence to definitively confirm or refute many of the claims surrounding coconut water. It certainly can be rehydrating in cases of mild dehydration- but likely only as much as water or sports drinks; and should be avoided in a number of situations. As far as its effects on cardiovascular risk, diabetes, inflammation, cancer, the skin and nervous system goes, the jury is still out.

What is your favourite type of coconut water?

References

Anurag, P.,  and Rajamohan, T. Cardioprotective effect of tender coconut water in experimental myocardial infarction. Plant Foods Hum Nutr 58:1–12 (2003). https://doi.org/10.1023/B:QUAL.0000040363.64356.05

iTi Tropicals. Young Coconuts Versus Mature Coconuts: The Facts. (Posted 10 March, 2014). https://ititropicals.com/blog/young-coconuts-versus-mature-coconuts-the-facts/.

Medeiros, V.F.L.P., and Medeiros, A.C.(2012). Therapeutic use of coconut water. J Surg Cl Res. 3(2):75-83. 

Murawski, E. (17 December, 2018). How Coconut Water is Made. Chowhound. https://www.chowhound.com/food-news/214828/how-coconut-water-is-made/

Preetha, P.P., Devi, V.G., and Rajamohan, T. (2013). Effects of coconut water on carbohydrate metabolism and pancreatic pathology of alloxan induced diabetic rats. European Journal of Integrative Medicine. 5(3):234-240. https://doi.org/10.1016/j.eujim.2012.12.005

Ranasinghe, C.S.,  Madurapperuma, W.S.,  Nainanayake, N.P.A.D., Mendis, H.C., and Fernando, W.P.K.K. (2009). Tender coconuts for export market: evaluation of cultivars and improved protocol for extended shelf-life. Indian Coconut Journal. 51(12):18-25.

Rao, S. S., and Najam, R. (2016). Coconut water of different maturity stages ameliorates inflammatory processes in model of inflammation. Journal of intercultural ethnopharmacology. 5(3):244–249. https://doi.org/10.5455/jice.20160402120142

Saat, M., Singh, R., Sirisinghe, R.G., and Nawawi, M. (2002). Rehydration after Exercise with Fresh Young Coconut Water, Carbohydrate-Electrolyte Beverage and Plain Water. Journal of Physiological Anthropology and Applied Human Science. 21(2):93-104. https://doi.org/10.2114/jpa.21.93

Sandhya, V.G., and Rajamohan, T. (2008). Comparative evaluation of the hypolipidemic effects of coconut water and lovastatin in rats fed fat–cholesterol enriched diet. Food and Chemical Toxicology. 46(12):3586-3592. https://doi.org/10.1016/j.fct.2008.08.030

Siti, T.Z., Danis, P, Bagus, S.A., Nuri, S., Brillian, J.E.M., and Alfiza, N.S. (2017). Effect of Tender Coconut Water on Blood Lipid Levels in High Fat Diet Fed Male Rats. Journal of Krishna Institute of Medical Sciences University. 6(2).

Yong, J. W., Ge, L., Ng, Y. F., and Tan, S. N. (2009). The chemical composition and biological properties of coconut (Cocos nucifera L.) water. Molecules (Basel, Switzerland). 14(12):5144–5164. https://doi.org/10.3390/molecules14125144

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