Spinach (Spinacia oleracea)
Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.
Acelga (Portuguese), aedspinat (Estonian), bo cai (Chinese), cheera (Malayalam), Chenopodiaceae (family), chlorophyll, digalactosyl diacylglycerol (DGDG), espinaca (Portuguese, Spanish), espinafre (Portuguese - Brazil), épinard (French), folates, folic acid, glycolipids, gobre palungo (Nepalese), goli spinat (Croatian), hourensou (Japanese), iron, isfanahk (Arabic), ispanahk (Arabic), ispanak (Turkish), ispany (Persian), lutein, monogalactosyl diacylglycerol (MGDG), oxalate, paala koora (Telugu), paalak (Hindi, Punjabi, Urdu), palunga (Nepali), paraj (Hungarian), pinatti (Finnish), pinni (Hindi), potassium, rau bó xôi (Vietnamese), retinoids, sabanekh (Arabic - Egypt), shi geum chi (Korean), shi gum chi (Korean), shpinat ogorodnyi (Russian), sigmchi (Korean), silicon, spanaki (Greek), spenat (Swedish), spenót (Hungarian), spermatophyte, špinača (Slovenian), spinach, spinach extract (NAO), spinach ferredoxin/ferredoxin reductase, spinach powder, Spinacia oleracea, spinacio (Italian), spinat (Danish, Dutch, Norwegian), Spinat (German), spinazi (Dutch), Spinner spinach, Springer spinach, sulfoquinovosyl diacylglycerol (SQDG), szpinak warzywny (Polish), tered (Hebrew), tered hagina (Hebrew), vitamin A, vitamin B6, zeaxanthin.
Note: The following plants are of a different genus and species than Spinacia oleracea: Indian spinach (Basella alba), New Zealand spinach (Tetragonia tetragonioides; T. expansa), and water spinach (Ipomoea aquatica), and they are not included in this monograph.
Spinach (Spinacia oleracea) is a good source of iron, folic acid, vitamin B6, nitrates, oxalates, beta-carotene, and lutein. In addition to its food value, spinach has a number of therapeutic uses.
The German Commission E reports the use of spinach for gastrointestinal disorders, blood-generating therapy, growth stimulation in children, appetite stimulation, convalescent support, and fatigue. Studies have also suggested its use as an anticancer agent, antioxidant, and cancer preventative. Spinach may also reduce age-related eyesight deterioration from macular degeneration and cataracts. More high-quality research is needed.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Age-related macular degeneration
Regular consumption of spinach may lower the risk of age-related macular degeneration (loss of vision). Low-quality studies investigating the correlation of the intake of carotenoids and vitamins found in spinach noted a significant trend for risk reduction. While this is promising, additional research is necessary before a conclusion can be made.
*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional.
Acne, alcoholism, Alzheimer's disease, antiaging, anti-inflammatory, antioxidant, bladder cancer, breast cancer, cancer (general), cancer (gallbladder), cancer prevention, carotenoid deficiency, cataracts, chronic disease (prevention), colon cancer, constipation, detoxification (removal of toxins from the body), digestion, diuretic (increases urine flow), duodenal ulcer (ulcer in the first part of the small intestine), esophageal cancer (cancer located between the throat and stomach), gastric cancer (stomach cancer), hemorrhoids, high blood sugar/glucose intolerance (glucose reduction), high cholesterol, intestinal inflammation, iron deficiency, laxative, lung cancer, megaloblastic anemia (anemia with abnormally large red blood cells), nerve pain, neural tube defects (prevention), osteoporosis (weakening of the bones), prostate cancer, rabies (prevention/vaccine/oral booster), rectal cancer, stomach cancer, stroke prevention, vitamin A deficiency, vitamin deficiencies (folic acid), weight loss.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
There is no proven safe or effective dose for spinach in adults.
Children (under 18 years old)
There is no proven safe or effective dose for spinach in children. Spinach poisoning has been reported in infants.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Avoid with known allergy or hypersensitivity to spinach, its constituents, or members of the Chenopodiaceae family. There have been reports of cross-reactivity between spinach and mushrooms, latex, and nickel. Allergic reaction symptoms including headache, flushing, oral allergy, contact dermatitis (rash after contact with an allergen), and alveolitis (inflammation of alveoli (air sacs) in lungs). Occupational asthma may be possible.
Side Effects and Warnings
Spinach is primarily consumed as a food. However, capsules containing spinach (often in combination with other vegetables or herbs) are sold commercially.
Spinach is likely safe in nonallergic individuals, including pregnant and breastfeeding women, when consumed in amounts generally found in foods.
Escherichia coli outbreaks have been linked to bagged raw spinach.
Spinach may decrease the risk of bleeding. Caution is advised in patients with bleeding disorders or those taking drugs, herbs, or supplements that may affect the risk of bleeding. Dosing adjustments may be necessary.
Spinach may cause kidney stones. Use cautiously in patients with a history of kidney stones.
Use cautiously in patients with a history of arthritis or gout.
Use cautiously in patients taking opioids, as spinach may increase the effect of narcotics.
Spinach may alter blood sugar levels. Caution is advised in patients with diabetes or abnormal glucose levels and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Avoid in infants less than four months old, due to the risk of methemoglobinemia (blood disorder).
Avoid in patients with a known allergy or hypersensitivity to spinach, its constituents, or members of the Chenopodiaceae family.
Pregnancy and Breastfeeding
Spinach is likely safe in nonallergic pregnant and breastfeeding women when consumed in amounts generally found in foods. Spinach is a good source of folic acid, which is recommended during pregnancy to reduce the risk of neural tube defects such as spina bifida.
Information on the effect of spinach on lactation is currently lacking in the National Institute of Health's Lactation and Toxicology Database (LactMed).
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Spinach may decrease the risk of bleeding and interfere with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
Spinach may alter blood glucose control or decrease blood sugar levels after meals. Caution is advised when using medications that may also affect blood sugar. Patients taking insulin or drugs for diabetes by mouth should be monitored closely by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Spinach may also interact with anticancer agents and opioids.
Interactions with Herbs and Dietary Supplements
Spinach may decrease the risk of bleeding and interfere with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically change the risk of bleeding, although this has not been proven in most cases.
Spinach may alter blood glucose control or decrease blood sugar levels after meals. Caution is advised when using herbs or supplements that may also affect blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
Spinach may also interact with anticancer herbs and supplements, antioxidant herbs and supplements, neurologic herbs and supplements, tomatoes, and vitamin K-rich foods.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.
Berson EL. Nutrition and retinal degenerations. Int Ophthalmol Clin 2000;40(4):93-111. View Abstract
Blomhoff R. Dietary antioxidants and cardiovascular disease. Curr Opin Lipidol 2005;16(1):47-54. View Abstract
Chen Z, Ye Z, Zeng L, et al. Clinical investigation on gastric oxalate absorption. Chin Med J (Engl) 2003;116(11):1749-1751. View Abstract
Chu YF, Sun J, Wu X, et al. Antioxidant and antiproliferative activities of common vegetables. J Agric Food Chem 2002;50(23):6910-6916. View Abstract
Couris RR, Tataronis GR, Dallal GE, et al. Assessment of healthcare professionals' knowledge about warfarin-vitamin K drug-nutrient interactions. J Am Coll Nutr 2000;19(4):439-445. View Abstract
Lomnitski L, Bergman M, Nyska A, et al. Composition, efficacy, and safety of spinach extracts. Nutr Cancer 2003;46(2):222-231. View Abstract
Herrera-Mozo I, Ferrer B, Luis Rodriguez-Sanchez J, et al. Description of a novel panallergen of cross-reactivity between moulds and foods. Immunol Invest 2006;35(2):181-197. View Abstract
Iijima H, Kasai N, Chiku H, et al. Structure-activity relationship of a glycolipid, sulfoquinovosyl diacylglycerol, with the DNA binding activity of p53. Int J Mol Med 2007;19(1):41-48. View Abstract
Kopsell DA, Lefsrud MG, Kopsell DE, et al. Spinach cultigen variation for tissue carotenoid concentrations influences human serum carotenoid levels and macular pigment optical density following a 12-week dietary intervention. J Agric Food Chem 2006;54(21):7998-8005. View Abstract
No authors listed. E. coli O157:H7 outbreak in the United States associated with bagged fresh spinach. Can Commun Dis Rep 2006;32(22):272. View Abstract
O'Neill ME, Carroll Y, Corridan B, et al. A European carotenoid database to assess carotenoid intakes and its use in a five-country comparative study. Br J Nutr 2001;85(4):499-507. View Abstract
Savino F, Maccario S, Guidi C, et al. Methemoglobinemia caused by the ingestion of courgette soup given in order to resolve constipation in two formula-fed infants. Ann Nutr Metab 2006;50(4):368-371. View Abstract
Seddon JM, Ajani UA, Sperduto RD, et al. Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration. Eye Disease Case-Control Study Group. JAMA 1994;272(18):1413-1420. View Abstract
Wang R, Furumoto T, Motoyama K, et al. Possible antitumor promoters in Spinacia oleracea (spinach) and comparison of their contents among cultivars. Biosci Biotechnol.Biochem 2002;66(2):248-254. View Abstract
Wilson RD, Davies G, Desilets V, et al. The use of folic acid for the prevention of neural tube defects and other congenital anomalies. J Obstet Gynaecol Can 2003;25(11):959-973. View Abstract
Copyright © 2013 Natural Standard (www.naturalstandard.com)
The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.
March 22, 2017