Spinach (Spinacia oleracea) is a flowering plant in the family of Amaranthaceae. It is native to central and southwestern Asia. It is an annual plant (rarely biennial), which grows to a height of up to 30 cm. Spinach may survive over winter in temperate regions. The leaves are alternate, simple, ovate to triangular-based, very variable in size from about 2-30 cm long and 1-15 cm broad, with larger leaves at the base of the plant and small leaves higher on the flowering stem. The flowers are inconspicuous, yellow-green, 3-4 mm diameter, maturing into a small hard dry lumpy fruit cluster 5-10 mm across containing several seeds.

History

Primitive forms of spinach are found in Nepal and that is probably where the plant was first domesticated. Other than the Indian subcontinent, it was unknown in the ancient world. After the early Muslim conquests the plant spread to other areas. In 647, it was taken to China, possibly by Persians. Muslim Arabs diffused the plant westward up to Islamic Spain. By the eleventh century it was a common plant in the Muslim world.

Spinach is thought to have originated in ancient Persia (Iran). Spinach made its way to China in the 7th century when the king of Nepal sent it as a gift to this country. Spinach has a much more recent history in Europe than many other vegetables. It was only brought to that continent in the 11th century, when the Moors introduced it into Spain. In fact, for a while, spinach was known as "the Spanish vegetable" in England.

Spinach was the favorite vegetable of Catherine de Medici, a historical figure in the 16th century. When she left her home of Florence, Italy, to marry the king of France, she brought along her own cooks, who could prepare spinach the ways that she especially liked. Since this time, dishes prepared on a bed of spinach are referred to as "a la Florentine."

Nutrition

Spinach is known as a rich source of iron. According to the USDA, a 180 gram serving of boiled spinach contains 6.43 mg of iron, whereas one 6 oz. (170 gram) ground hamburger patty contains at most 4.42 mg. Thus spinach does contain a relatively high level of iron, compared to other vegetable and meat sources.

Ultimately, the bioavailability of iron is dependent on its absorption. This is influenced by a number of factors. Iron enters the body in two forms: nonheme iron and heme iron. All of the iron in grains and vegetables, and about three fifths of the iron in animal food sources (meats), is nonheme iron. The much smaller remaining portion from meats is heme iron.Williams, S.R. (1993) Nutrition and Diet Therapy 7th ed. Mosby: St. Loius, MO (Williams, 1993)

The larger portion of dietary iron (nonheme) is absorbed slowly in its many food sources, including spinach. This absorption may vary widely depending on the presence of binders such as fiber or enhancers, such as vitamin C. Therefore, the body's absorption of non-heme iron can be improved by consuming foods that are rich in vitamin C. However, spinach contains high levels of oxalate. Oxalates bind to iron to form ferrous oxalate, thus making the iron in spinach unavailable, plus high amounts of oxalates remove iron from the body. Therefore, a diet high in oxalate (or phosphate or phytate) leads to a decrease in iron absorption. As a result around 90% of the iron content in Spinach will be released in urine, and not absorbed in the body.Fact: date=September 2008