Eating Wasabia japonica to stay Healthy
Wasabi (Wasabia japonica) is an edible plant member of the Cruciferae family, which includes cabbage, turnips, and mustard. Wasabia japonica shares the anticancer benefits of this family.
Native to Japan where it has been cultivated since the tenth century, it is still considered a staple condiment in that country. Traditional preparation involves using a sharkskin grater called an oroshi.
Wasabia japonica’s culinary popularity and chemical bioactivity make it extremely valuable medicinally and industrially. Demand for Wasabia japonica has created a relatively short supply, higher prices, and new commercial opportunities.
These new opportunities include research and development of cultivation technologies, particularly in New Zealand, and exportation from Japan of seiyo wasabi, or Western wasabi—imitations made of horseradish (Cochlearia armoracia). Western and Japanese wasabi are both highly prized by the Japanese and they are often interchanged.
Wasabia japonica is a perennial, root-like rhizome that is roughly cylindrical in shape. A brownish-green skin covers its pale green flesh. The plant grows to about 18 in (46 cm) in height and produces leaves on long stems from the crown of the plant. As the plant ages, the leaves fall off and a rhizome, or creeping above ground stem, is formed, from which new buds are formed.
The rhizome is the most highly prized part of the plant that is used. The highest quality Wasabia japonica, whose translated name is mountain hollyhock (also known as Sawa wasabi), thrives in cool water. It grows naturally along the edges of cold mountain streams, and this method has been used in New Zealand since 1990.
When cultivated in Japan, rather than wild-crafted (harvested randomly from its natural growing places), it is grown on tree shaded, terraced gravel beds covered by a thin layer of cool running mountain water or on artificially shaded gravel ridges formed in larger river beds. In New Zealand Sawa Wasabi is grown in very specialised environmentally controlled structures to produce the most chemical bioactive Wasabia japonica in the world.
A lower quality Wasabia japonica (oka wasabi) is grown in fields in heavily manured ground. These are subject to the diseases and insect attacks common to all members of the Cabbage family. Also after three crops the ground must be left fallow for a minimum of five years before being replanted with Wasabia japonica.
There are a number of different varieties of Wasabia japonica. The two most common are; Daruma—considered to have a more attractive appearance—and Mazuma—considered to have more heat.
Wasabia japonica can be described as being “hot and fiery without burning,” which changes to a sweetness that lingers in the mouth.
Historically, Wasabia japonica has been consumed as a condiment, used similarly to horseradish or mustard. Its pungent flavour and aroma may add a piquant flavour to sashimi, sushi, marinades or sauces, and rice, noodle, and fish dishes. In Japanese restaurants around the World, sashimi and sushi may be served with a small mound of grated Wasabia japonica or Wasabia japonica paste.
Non-traditional uses include adding Wasabia japonica to mashed potatoes, tuna sandwiches, or blending it with soy sauce. There is now a Wasabi Spirit available which allows a whole new range of interesting drinks to be added to the bartenders repertoire. Wasabia japonica leaves marinated in sake, brine, or soy sauce, are eaten with a bowl of rice.
In addition to its flavour, Wasabia japonica has another benefit. Traditional Japanese cuisine includes raw fish, which is a potential source of parasites and bacteria. Wasabia japonica’s anti-parasitic, antimicrobial, and antibiotic abilities may be a preventive against food poisoning.
When the antibacterial activity of different foods against Escherichia coli (E. coli) and Staphylococcus bacteria were compared, it was found that cruciferous plants possess significant antibacterial activity, with the highest activity being found in Wasabia japonica rhizomes.
Other studies found that Wasabia japonica may be effective against the tooth-adhering ability of the bacteria Streptococcus mutans, thus inhibiting dental plaque and decay.
Of special note are the numerous studies demonstrating Wasabia japonica’s effectiveness against stomach cancer cells. It was found that the induction of stomach cancer in rats was suppressed when they were given Wasabia japonica. The risk of hormone-related malignancies, such as breast and prostate cancer, may also be lowered.
Some researchers believe that the cruciferous vegetables help the body eliminate excess endogenous (produced from within) and exogenous (produced from without but ingested or absorbed) hormones, such as estrogens. This action may be a result of Wasabia japonica’s ability to stimulate the liver and gallbladder, aiding in the digestion of fatty foods and the processing of food nutrients.
Other medicinal benefits attributed to Wasabia japonica include its effectiveness against diarrhoea, blood clots, inflammation, and asthma. Its pungent aroma may help relieve sinusitis and bronchitis. Although the amounts absorbed from culinary use may be negligible, Wasabia japonica also contains potassium, calcium, and vitamin C.
Some industrial applications of Wasabia japonica under investigation include its usefulness in the development of other antibiotics, due to its own antibiotic qualities; its effectiveness as a fungicide against the blackleg fungus that threatens plants commercially valued for their oil, such as rapeseed and canola; and its possible use as an effective alternative to chemically toxic wood preservatives.
Wasabi is most commonly found in powder or paste form. However, due to the scarcity and price of high quality Wasabia japonica, many of these preparations—including imports from Japan for retail sale and those served in Japanese restaurants—are imitations made of horseradish, mustard, a starchy binder, and colouring. Wasabi paste may be made from a powdered wasabi by adding cold water, and letting it stand 5 – 10 minutes to allow the flavour and heat to develop.
See the article How to get the best from your Powdered wasabi for information on storing and using Wasabi Powder.
Wasabi in any form (even the fake stuff) should not come into direct contact with the eyes or nasal passages.
Due to its anti-inflammatory, antibiotic, antibacterial, anti-parasitic, anticoagulant, and anti-asthmatic effects, the use of Wasabia japonica may magnify the effects of certain pharmaceutical drugs used for similar purposes.
People with ulcers, oesophageal reflux, kidney disorders, gastrointestinal disease, or those using hormone replacement therapy, are advised to consult with a healthcare professional before using Wasabia japonica.
Due to its liver and gallbladder stimulating effects, in rare cases, eating Wasabia japonica may cause gastrointestinal disturbances, including diarrhoea and nausea.
There are no known interactions between prescribed medicines and Wasabia japonica. Always check with your medical professional if unsure.
There are significant benefits from eating Wasabia japonica as part of your normal diet. This can be taken as a food or as a supplement. You just need to make sure that it is the True Wasabia japonica, and not the coloured horseradish mix peddled in the shops and supermarkets. 🙂