(''Sargassum fusiforme'', syn. ''Hizikia fusiformis''), sometimes called hiziki, is a brown sea vegetable growing wild on rocky coastlines of East Asia. Hijiki has been a part of the Japanese culinary sphere and diet for centuries. It is rich in dietary fiber and essential minerals such as calcium, iron, and magnesium. According to

Japanese folklore Japanese folklore encompasses the informally learned folk traditions of Japan and the Japanese people as expressed in its oral traditions, customs, and material culture. In Japanese, the term is used to describe folklore. The academic study o ...

, hijiki aids health and beauty, and thick, black, lustrous hair is connected to regular consumption of small amounts. Hijiki has been sold in

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and ...

natural products stores for 30 years and its culinary uses have been adopted in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

. Recent studies have shown that hijiki contains potentially

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a sub ...

quantities of inorganic

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, b ...

, and the food safety agencies of several countries (excluding Japan), including

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

, the

, and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

, have advised against its consumption.

In the West

In 1867 the word "hijiki" first appeared in an English-language publication: ''A Japanese and English Dictionary'' by James C. Hepburn. Starting in the 1960s, the word "hijiki" started to be used widely in the United States, and the product (imported in dried form from Japan) became widely available at natural food stores and Asian-American grocery stores, due to the influence of the macrobiotic movement, and in the 1970s with the growing number of Japanese restaurants.

Appearance and preparation

Hijiki is green to brown in colour when found in the wild. A fisherman and a professional diver harvest the hijiki with a

sickle A sickle, bagging hook, reaping-hook or grasshook is a single-handed agricultural tool designed with variously curved blades and typically used for harvesting, or reaping, grain crops or cutting Succulent plant, succulent forage chiefly for feed ...

low tide Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables c ...

of the

spring tide Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tabl ...

of May from March. After collection, the seaweed is boiled and dried to be sold as dried hijiki. Dried processed hijiki turns black. To prepare dried hijiki for cooking, it is first soaked in water then cooked with ingredients like soy sauce and sugar to make a dish. In

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

, hijiki is normally eaten with other foods such as vegetables or fish. It may be added to foods that have been steamed, boiled, marinated in

soy sauce Soy sauce (also called simply soy in American English and soya sauce in British English) is a liquid condiment of Chinese origin, traditionally made from a fermented paste of soybeans, roasted grain, brine, and ''Aspergillus oryzae'' or '' As ...

or fish sauce, cooked in oil, or added to soup, stir fries or quiches. Hijiki seaweed may be mixed with rice for

sushi is a Japanese dish of prepared , usually with some sugar and salt, accompanied by a variety of , such as seafood, often raw, and vegetables. Styles of sushi and its presentation vary widely, but the one key ingredient is "sushi rice," also ...

but is not used as a wrap to prepare sushi. Konjac (konnyaku) gel in Japan is typically prepared with hijiki mixed in to give it its characteristic grey color and texture. In

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic ...

, the seaweed is called ''tot'' () and eaten as '' namul'' (seasoned vegetable side dish) or cooked with '' bap'' (rice).

Nutrition

Hijiki contains

dietary fiber Dietary fiber (in British English fibre) or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition, and can be grouped generally by t ...

and minerals such as iron,

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar ...

, and

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...

. Dietary fiber is good for the intestine and iron helps to prevent

anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, t ...

. The ratio of calcium to magnesium in hijiki is 2 to 1.

Arsenic health risk

Several government food safety agencies advise consumers to avoid consumption of hijiki seaweed. Test results have indicated that levels of

inorganic In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemist ...

were significantly higher than in other types of seaweed. These results have been independently verified. Government food safety agencies that advise against consumption include the Canadian Food Inspection Agency (CFIA), the

Food Standards Agency The Food Standards Agency is a non-ministerial government department of the Government of the United Kingdom. It is responsible for protecting public health in relation to food in England, Wales and Northern Ireland. It is led by a board ap ...

(FSA) of the United Kingdom, and the

United States Department of Agriculture The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of comme ...

(USDA). The Ministry of Health, Labour and Welfare of Japan has responded with a report pointing out that while the consumption of more than 4.7 g hijiki seaweed per day could result in an intake of inorganic arsenic that exceeds the tolerable daily intake for this substance, the average daily consumption for Japanese people is estimated at 0.9 g. Several of the reports from other food safety agencies acknowledged that occasional hijiki consumption was unlikely to cause significant health risks but advised against all consumption regardless. Although no known illnesses have been associated with consuming hijiki seaweed to date, inorganic arsenic has been identified as

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive sub ...

ic to humans. Exposure to inorganic arsenic has been linked with

gastrointestinal The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans and ...

effects,

, and liver damage.https://www.epa.gov/sites/production/files/2016-09/documents/arsenic-compounds.pdf People who follow a

macrobiotic diet A macrobiotic diet (or macrobiotics) is a fad diet based on ideas about types of food drawn from Zen Buddhism. The diet tries to balance the supposed yin and yang elements of food and cookware. Major principles of macrobiotic diets are to reduce ...

that often includes large amounts of seaweed may be at greater risk.

References

External links

Canadian Food Inspection Agency
— Factsheet
Food and Environmental Hygiene Department of Hong Kong
— Hijiki and Arsenic
Food Standards Agency of the United Kingdom
— Hijiki: your questions answered

— Hijiki media release

{{Taxonbar, from=Q1204264 Fucales Japanese condiments Japanese cuisine terms Japanese vegetables Korean condiments Edible seaweeds