Spinach

Spinach (Spinacia oleracea) is a leafy green flowering plant native to central and western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common edible vegetable consumed either fresh, or after storage using preservation techniques by canning, freezing, or dehydration. It may be eaten cooked or raw, and the taste differs considerably; the high oxalate content may be reduced by steaming.

This article is about the plant, Spinacia oleracea. For other leaf vegetables, see Spinach (disambiguation).

Spinach
Spinach plant with flowers
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Caryophyllales
Family:	Amaranthaceae
Genus:	Spinacia
Species:	S. oleracea
Binomial name
Spinacia oleracea L.

It is an annual plant (rarely biennial), growing as tall as 30 cm (1 ft). Spinach may overwinter in temperate regions. The leaves are alternate, simple, ovate to triangular, and very variable in size: 2–30 cm (1–12 in) long and 1–15 cm (0.4–5.9 in) 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 (0.1–0.2 in) in diameter, and mature into a small, hard, dry, lumpy fruit cluster 5–10 mm (0.2–0.4 in) across containing several seeds.

In 2018, world production of spinach was 26.3 million tonnes, with China alone accounting for 90% of the total.[1]

Etymology

The English word "spinach" dates to the late 14th century from espinache (French, épinard) of uncertain origin.[2]

Taxonomy

Common spinach, S. oleracea, was long considered to be in the family Chenopodiaceae, but in 2003 that family was merged into the Amaranthaceae in the order Caryophyllales. Within the family Amaranthaceae sensu lato, Spinach belongs to the subfamily Chenopodioideae.

Description

Spinach, raw

Nutritional value per 100 g (3.5 oz)
Energy	97 kJ (23 kcal)
Carbohydrates	3.6 g
Sugars	0.4 g
Dietary fiber	2.2 g
Fat	0.4 g
Protein	2.9 g
Vitamins	Quantity %DV^†
Vitamin A equiv. beta-Carotene lutein zeaxanthin	59% 469 μg 52% 5626 μg 12198 μg
Vitamin A	9377 IU
Thiamine (B1)	7% 0.078 mg
Riboflavin (B2)	16% 0.189 mg
Niacin (B3)	5% 0.724 mg
Vitamin B6	15% 0.195 mg
Folate (B9)	49% 194 μg
Vitamin C	34% 28 mg
Vitamin E	13% 2 mg
Vitamin K	460% 483 μg
Minerals	Quantity %DV^†
Calcium	10% 99 mg
Iron	21% 2.71 mg
Magnesium	22% 79 mg
Manganese	43% 0.897 mg
Phosphorus	7% 49 mg
Potassium	12% 558 mg
Sodium	5% 79 mg
Zinc	6% 0.53 mg
Other constituents	Quantity
Water	91.4 g
Link to USDA database entry
Units μg = micrograms • mg = milligrams IU = International units
^†Percentages are roughly approximated using US recommendations for adults. Source: USDA Nutrient Database

Spinach is an annual plant (rarely biennial) growing as tall as 30 cm (1 ft). Spinach may overwinter in temperate regions. The leaves are alternate, simple, ovate to triangular, and very variable in size: 2–30 cm (1–12 in) long and 1–15 cm (0.4–5.9 in) 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 (0.1–0.2 in) in diameter, and mature into a small, hard, dry, lumpy fruit cluster 5–10 mm (0.2–0.4 in) across containing several seeds.

Nutrients

Raw spinach is 91% water, 4% carbohydrates, 3% protein, and contains negligible fat. In a 100 g (3.5 oz) serving providing only 23 calories, spinach has a high nutritional value, especially when fresh, frozen, steamed, or quickly boiled. It is a rich source (20% or more of the Daily Value, DV) of vitamin A, vitamin C, vitamin K, magnesium, manganese, iron and folate. Spinach is a good source (10-19% of DV) of the B vitamins riboflavin and vitamin B₆, vitamin E, calcium, potassium, and dietary fiber. Although spinach is touted as being high in iron and calcium content, and is often served and consumed in its raw form, raw spinach contains high levels of oxalates, which block absorption of calcium and iron in the stomach and small intestine. Spinach cooked in several changes of water has much lower levels of oxalates and is better digested and its nutrients absorbed more completely.[3]

Iron

Spinach, along with other green, leafy vegetables,[4] contains an appreciable amount of iron attaining 21% of the Daily Value in a 100 g (3.5 oz) amount of raw spinach. For example, the United States Department of Agriculture states that a 100 g (3.5 oz) serving of cooked spinach contains 3.57 mg of iron,[5] whereas a 100 g (3.5 oz) ground hamburger patty contains 1.93 mg of iron.[6] However, spinach contains iron absorption-inhibiting substances, including high levels of oxalate, which can bind to the iron to form ferrous oxalate and render much of the iron in spinach unusable by the body.[7] In addition to preventing absorption and use, high levels of oxalates remove iron from the body.[7][8]

Calcium

Spinach also has a moderate calcium content which can be affected by oxalates, decreasing its absorption.[7][9] The calcium in spinach is among the least bioavailable of food calcium sources.[7][10] By way of comparison, the human body can absorb about half of the calcium present in broccoli, yet only around 5% of the calcium in spinach.[11]

Vitamin K

A quantity of 3.5 ounces of spinach contains over four times the recommended daily intake of vitamin K. For this reason, individuals taking the anticoagulant warfarin – which acts by inhibiting vitamin K – are instructed to minimize consumption of spinach (as well as other dark green leafy vegetables) to avoid blunting the effect of warfarin.[12]

Production, marketing, and storage

Spinach production - 2018

Country	Production (millions of tonnes)
China	23.8
United States	0.38
Japan	0.23
Turkey	0.23
World	26.3
Source: UN Food & Agriculture Organization, Statistics Division (FAOSTAT)[1]

In 2018, world production of spinach was 26.3 million tonnes, with China alone accounting for 90% of the total.[1]

Fresh spinach is sold loose, bunched, or packaged fresh in bags. Fresh spinach loses much of its nutritional value with storage of more than a few days.[13] Fresh spinach is packaged in air, or in nitrogen gas to extend shelf life. While refrigeration slows this effect to about eight days, fresh spinach loses most of its folate and carotenoid content over this period of time. For longer storage, it is canned, or blanched or cooked and frozen.[13]

Some packaged spinach is exposed to radiation to kill any harmful bacteria. The Food and Drug Administration approves of irradiation of spinach leaves up to 4.0 kilograys, having no or only a minor effect on nutrient content.[14] Spinach may be high in cadmium contamination depending on the soil and location where the spinach is grown.[15]

In popular culture

The comics and cartoon character Popeye the Sailor Man has been portrayed since 1931 as having a strong affinity for spinach, particularly the canned variety. He becomes physically stronger after consuming it.[16]

History

Spinach is thought to have originated about 2000 years ago in ancient Persia from which it was introduced to India and ancient China via Nepal in 647 AD as the "Persian vegetable".[17] In AD 827, the Saracens introduced spinach to Sicily.[18] The first written evidence of spinach in the Mediterranean was recorded in three 10th-century works: a medical work by al-Rāzī (known as Rhazes in the West) and in two agricultural treatises, one by Ibn Waḥshīyah and the other by Qusṭus al-Rūmī. Spinach became a popular vegetable in the Arab Mediterranean and arrived in Spain by the latter part of the 12th century, where Ibn al-ʻAwwām called it raʼīs al-buqūl, 'the chieftain of leafy greens'.[19] Spinach was also the subject of a special treatise in the 11th century by Ibn Ḥajjāj.[20]

Spinach first appeared in England and France in the 14th century, probably via Spain, and gained common use because it appeared in early spring when fresh local vegetables were not available.[17] Spinach is mentioned in the first known English cookbook, the Forme of Cury (1390), where it is referred to as 'spinnedge' and/or 'spynoches'.[17][21] During World War I, wine fortified with spinach juice was given to injured French soldiers with the intent to curtail their bleeding.[17][22]

See also

• Green leafy vegetable
• Ipomoea aquatica
• Kale
• Mountain spinach
• Palmer amaranth
• Pkhali
• Spinach dip
• Spinach in the United States
• Spinach salad
• Spinach soup
• Tetragonia tetragonioides
• White goosefoot

References

1. "Crops/Regions/World List for Production Quantity of Spinach in 2018". UN Food & Agriculture Organization. 2018. Retrieved 24 April 2020.
2. "Spinach". Online Etymology Dictionary, Douglas Harper. 2019. Retrieved 6 March 2019.
3. "Osteoporosis Diet & Nutrition: Foods for Bone Health". National Osteoporosis Foundation. 2015-12-21. Retrieved 2019-11-18.
4. "Raw spinach per 100 g, Full Report from the USDA National Nutrient Database". US Department of Agriculture, National Nutrient Database for Standard Reference Release 27. 2014. Retrieved 1 February 2015.
5. "Spinach, cooked, drained, without salt". US Department of Agriculture, National Nutrient Database for Standard Reference 1 Release April, 2018. 2018. Retrieved 31 May 2019.
6. "FoodData Central". FoodData Central. Retrieved 2019-11-18.
7. Noonan SC, Savage GP (1999). "Oxalate content of foods and its effect on humans" (PDF). Asia Pac J Clin Nutr. 8 (1): 64–74. doi:10.1046/j.1440-6047.1999.00038.x. PMID 24393738.CS1 maint: uses authors parameter (link)
8. Williams, Sue Rodwell; Long, Sara (1997). Nutrition and diet therapy. p. 229. ISBN 978-0-8151-9273-2.
9. Insel, Paul M.; Turner, R. Elaine; Ross, Don (2003). Nutrition. p. 474. ISBN 978-0-7637-0765-1. Retrieved 2009-04-15.
10. Heaney, Robert Proulx (2006). Calcium in human health. p. 135. ISBN 978-1-59259-961-5. Retrieved 2009-04-15.
11. Whitney E, Rady Rolfes S (Jan 1, 2010). Understanding Nutrition. Cengage Learning. ISBN 0538734655.CS1 maint: uses authors parameter (link)
12. Sheps SG (19 April 2018). "Warfarin diet: What foods should I avoid?". Mayo Clinic. Retrieved 6 March 2019.
13. "Storage time and temperature effects nutrients in spinach". Retrieved 2008-07-05.
14. Bliss RM (27 May 2010). "Nutrient retention of safer salads explored". US Department of Agriculture.
15. "ToxGuide for cadmium" (PDF). Atlanta, GA: Agency for Toxic Substances and Disease Registry, US Department of Health and Human Services. October 2012.
16. Gabbatt, Adam (8 December 2009). "E.C. Segar, Popeye's creator, celebrated with a Google doodle". The Guardian. Retrieved 5 May 2010.
17. "Spinach history - origins of different types of spinach". Vegetable Facts. 2019. Retrieved 2 November 2019.
18. Rolland, Jacques L.; Sherman, Carol (2006). The Food Encyclopedia. Toronto: Robert Rose. pp. 335–338. ISBN 9780778801504.
19. Ibn al-ʻAwwām, Yaḥyá ibn Muḥammad. "23.8". Kitāb al-Filāḥah. Retrieved July 30, 2014.
20. Clifford A. Wright. Mediterranean Vegetables: A Cook's ABC of Vegetables and their Preparation in Spain, France, Italy, Greece, Turkey, the Middle East, and North Africa, with More than 200 Authentic Recipes for the Home Cook. (Boston: Harvard Common Press, 2001). pp. 300-301.
21. Rolland, Jacques; Sherma, Carol (2006). Spinach. The Food Encyclopedia: Over 8,000 Ingredients, Tools, Techniques and People. Toronto: Robert Rose. Archived from the original on July 24, 2011. Retrieved March 7, 2010.
22. Margaret Grieve; Maud Grieve (1 June 1971). A modern herbal: the medicinal, culinary, cosmetic and economic properties, cultivation and folk-lore of herbs, grasses, fungi, shrubs, & trees with all their modern scientific uses. Courier Dover Publications. pp. 761–. ISBN 978-0-486-22799-3. Retrieved 13 August 2010.

External links

• Chisholm, Hugh, ed. (1911). "Spinach" . Encyclopædia Britannica (11th ed.). Cambridge University Press.