Coconut Water: Nutrients, What Research Shows and Safety

Coconut water is the clear liquid from inside the coconut, Cocos nucifera (palm family, Arecaceae). It is sold fresh in the nut, or bottled and boxed as a ready-to-drink beverage. People drink it as a natural-tasting alternative to soda or sports drinks and for its potassium. This page covers coconut water as a drink. It keeps it apart from coconut milk, coconut oil, and the lab and animal findings that are sometimes used to sell it. [1] [2]

Read this first

• It has sugar and calories, unlike plain water. The USDA unsweetened ready-to-drink item lists 18 kcal and 3.92 g sugars per 100 g, so about 44 kcal and 9.6 g sugars in a 1 cup (245 g) serving. [1]
• It is a notable source of potassium. About 404 mg per cup, or about 9% of the FDA Daily Value. [1] People with kidney disease or on medicines that raise potassium should ask a clinician first. A case report titled "Coconut water-induced hyperkalaemia" exists, and a 1992 trial authors cautioned against use in impaired kidney function. [12] [13] [14]
• Rehydration trials are small and mixed. In several small studies in fit young men, coconut water rehydrated about as well as a sports drink and better than or similar to plain water, but one found no benefit over water, and one found more bloating than a sports drink. [3] [4] [5] [6]
• Claims about blood pressure, diabetes and cholesterol rest mostly on rat studies, plus one small non-randomized human study. [9] [10] [11]
• Evidence in one line: an acceptable, tasty fluid with potassium and some natural sugar, not a proven treatment for any disease.

What is in it (USDA values)

The values below are for unsweetened ready-to-drink coconut water (USDA FoodData Central item 174831, SR Legacy). [1] The serving column is the USDA household portion of 1 cup, 245 g. [1]

% Daily Value uses the FDA 2016 Daily Values; values vary with the coconut, ripeness, processing and brand. The serving figures are the 100 g values multiplied by 2.45. USDA also lists raw liquid from coconuts (FDC 170174), which shows more potassium (250 mg per 100 g) and sodium (105 mg per 100 g) and less sugar (2.61 g per 100 g) than the ready-to-drink item, so fresh and packaged coconut water can differ. [2] USDA lists no fiber, fat or caffeine in the packaged item. [1]

Other compounds: coconut water has been studied in the lab for phenolic and antioxidant compounds, but the sources we read for this page were animal or lab studies. [10] [11] We did not find a human trial showing these compounds act when the drink is consumed.

What research says

Eaten as food vs taken as other products. The trials used coconut water as a drink. Coconut milk, coconut oil and powders are different products; see coconut milk beverage and coconut oil. We did not see funding statements in the records we read; some trials may have been industry supported.

How much is a normal serving

The USDA household portion is 1 cup (245 g), about 44 kcal with 9.6 g of sugars. [1] That is information, not a prescription. WHO advises keeping free sugars below 10% of daily energy (about 50 g for a 2,000 kcal diet), with more benefit possible below 5%. [15] We did not read whether the sugar in coconut water is counted as "free sugar" in official guidance, so check labels, especially for sweetened products: USDA data on this page are for an unsweetened product. [1]

Safety, allergy and medicines

• Potassium and kidney disease: MedlinePlus says people with chronic kidney disease may not clear extra potassium and may need a low-potassium diet, and that some medicines can raise potassium. [14] A 2012 case report titled "Coconut water-induced hyperkalaemia" describes high potassium linked to coconut water (we read only its title and index terms). [12] See foods, kidney disease, potassium and oxalates.
• Medicines: MedlinePlus says some medicines can raise potassium, but it does not name them on the page we read. Ask a pharmacist whether yours do. [14]
• Sugar and diabetes: USDA lists 9.6 g of sugars per cup. People with diabetes should count it as carbohydrate; see foods for blood sugar control. [1]
• Stomach upset: coconut water caused more bloating and stomach upset than a sports drink in one trial. [5]
• Diarrhea in children: do not rely on it in place of oral rehydration solution; WHO recommends ORS and says to see a health professional for persistent diarrhea, blood in stool or signs of dehydration. [16]
• Allergy: we did not read a source on coconut allergy for this page. As a general rule, call 911 (or your local emergency number) for swelling of the face or throat or trouble breathing after any food or drink.
• Pregnancy and young children: we did not read an official statement specific to coconut water.

Choosing, storing and food safety

• Check whether the label says "unsweetened" or lists added sugar or flavors; the USDA data here are for an unsweetened product. [1]
• Fresh and packaged products differ in potassium, sodium and sugar. [1] [2]
• We did not read a source on storing opened coconut water, so this page makes no claim on that. Follow the label.

Related pages

• Coconut milk beverage
• Sports and electrolyte drinks
• Coconut (fruit)
• Foods, kidney disease, potassium and oxalates
• Foods and medicine interactions
• Foods for blood pressure