What most people know about water chestnuts, sometimes more specifically called Chinese water chestnuts, are the basics: they’re white, have a crunchy texture and a fresh, mild taste, and are often used in Chinese cooking. In the West, most who use the small, round “corms” – short, underground, slightly bulbous stem bases – in their culinary endeavors buy them either whole or sliced in a can.
Water chestnuts are perennials from a family of plants called sedge, a type of marshy grass with the edible part appearing at the bottom very much like a real chestnut in shape and color. From the Cyperaceae family, these aren’t actually nuts but an aquatic vegetable. Each has a similar size and mildly sweet apple-coconut flavor.
Somewhat subdued into blandness when canned, fresh water chestnuts are both sweeter and more firm. Usually available in specialty groceries or supermarkets, they should be washed thoroughly and peeled with a sharp knife, especially if to be eaten raw. At this point, adding a few drops of lemon juice keeps them from turning brown when steamed or sautéed. Once peeled, they’ll only remain fresh in water that’s changed daily for two to three days.
Because they’re so popular in tropical countries like Thailand, Vietnam, China, and Japan as well as Australia, water chestnuts are often rotated with rice in paddy fields. Whether thinly sliced in soups, minced as an egg roll ingredient, or sautéed in a stir fry with snow peas, coconut oil, and ginger, water chestnuts remain crispy even after cooking. They’re the main ingredient in a noted Thai dessert, tabtim krob,and in the West they’re sometimes wrapped with bacon strips as an hors d’oeuvre. In Indonesia they’re blended into a drink.
Chinese water chestnuts shouldn’t be confused with a completely different species, the European water chestnut of the genus Lythraceae. Also called water caltrop (trapa natans – trapa for the Latin “thistle”) or horned chestnut, this aquatic plant was imported to the U.S. from Asia in the early part of the 20th century. Because of their thorny spikes and invasive nature (not to mention toxins) this plant is the bane of the east coast tourism trade, so selling any type of water chestnut plant species is reportedly banned from most of the Southern states, including Maryland.
Health Benefits of Water Chestnuts
While water chestnuts don’t have an overwhelming amount of detailed nutritional information, they do seem to have a reputation in traditional Asian and aboriginal medicine. They’ve been ground into powder, juiced, sliced, boiled, and eaten raw, steamed, or steeped in rice wine and used as a curative and food supplement.
Drinking water chestnut juice has been touted as a way to alleviate nausea, relieve suffering from jaundice, and detoxify the body from impurities. Making the powder into a paste is still used as a remedy for inflammation and is said to be useful, stirred up in water, as a cough elixir and for easing patients with measles.
Nutritionally, water chestnuts provide 10% each of the daily recommended value in vitamin B6, potassium (350 to 360 mg per ½ cup), copper, riboflavin, and manganese, with a respectable array of smaller amounts of other vitamins and minerals, as well. The corms are a rich source of carbohydrates, which relates itself in a starchy texture. Fiber is another ingredient in very good supply, which is effective for keeping your system running smoothly. However, water chestnut has no cholesterol to speak of or vitamin A at all. Fresh raw water chestnuts contain slightly more fat than the canned variety, but it’s the good kind.
Studies have found water chestnuts to contain flavonoid antioxidants like catechins, specifically epicatechins (as do dark chocolate, red wine, and green tea). Early aboriginal medicine men crushed the outsides of the bulb for wound application and healing, which science now knows releases antimicrobial effects. Inside water chestnuts are an antibiotic compound called “puchin” which acts in immune function like penicillin.
Water Chestnuts Nutrition Facts
Serving Size: 3.5 ounces (100 grams), raw
|Calories from Fat
*Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
Studies on Water Chestnuts
Experiments on water chestnuts were conducted to determine what antioxidant activity and major phenolic compound components they contain. Extracts were found to strongly inhibit linoleic acid oxidation and free radicals, superoxide anions (negatively charged ions) and hydroxyl radicals, superior to ascorbic acid and butylated hydroxytoluene (BHT), two commercially-used antioxidants, as well as a relatively higher reducing power compared with BHT. Major phenolic presence found in water chestnuts exhibited abundant potential for antioxidant activity, which scientists reported could be useful for nutritional and medicinal functions.1
A very detailed study listed a number of useful phenolics contained in water chestnuts, including gallic acid and vanillin, hydrocinnamic acids such as ferulic, caffeic, and p-coumaric acids, the flavonoids quercetin and kaempferol, the flavonols apignnin and luteolin, along with catechins and epicatechins.2 These are just a few of the compounds science has already determined have dramatically positive effects on numerous diseases.
Water Chestnuts Healthy Recipe:
Endive and Water Chestnut Salad
|2 endives, leaves separated
||2 cups of canned, sliced water chestnuts, drained
||1 cup walnut pieces
||1 or 2 mandarin oranges, sectioned
|1 small red pepper, diced
|2 Tbsp. honey
||1 Tbsp. white wine vinegar
||Juice of 1 lime
||½ tsp. cayenne pepper
|½ tsp. salt
In a small bowl, combine the dressing ingredients with a whisk. Gently combine the salad ingredients in a larger serving bowl, drizzle dressing over salad, toss gently, and enjoy.
Water Chestnuts Fun Facts
Eleocharis dulcis (water chestnut) is used for making salt in Zimbabwe.
A perfect example of the word not being the thing, two types of aquatic plants called water chestnuts are two distinct plant species. The edible kind is Eleocharis dulcis, a corm with a shape like a small chestnut, from the Cyperaceae family of plants, while the Trapa natans (family Lythraceae) is thorny, invasive, and often toxic.
The firm, white, crunchy water chestnut, not a nut but a vegetable, is often purchased canned, but sweeter when obtained fresh. It can be eaten raw and peeled (after thorough washing) or steamed and used in stir fries, soups, or salads.
Nutritionally, water chestnuts have a good number of vitamins and minerals such as fiber, vitamin B6, copper, riboflavin, and manganese, but the phenolics are what set this food apart. Free radical-scavenging activity and disease-fighting capability comes with phenolics and flavonoids like vanillin, hydrocinnamic acids, the flavonoids quercetin and kaempferol, and the flavonols apignnin, luteolin, catechins and epicatechins. These compounds have the potential to fight numerous diseases, making water chestnuts much more than just a crunchy ingredient for chop suey.