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Green coffee

Synonyms/Common Names/Related Substances:

  • 2-Methoxy-3-(2-methylpropyl)-pyrazine, 2-methoxy-4-vinylphenol, 2-methoxy-5-vinylphenol, 2-methylbutanoic acid, 3-isobutyl-2-methoxypyrazine, 3-methyl butanoic acid, 3-methyl butanol, 3-methylbut-2-enoyl disaccharides, 3-methylbut-2-enoyl-1-O-beta-D-glucopyranosyl-beta-D-apiofuranoside, 3-methylbutanoic acid, 3-methylbutanoyl disaccharides, 3-methylbutanoyl-1-O-beta-D-glucopyranosyl-beta-D-apiofuranoside, 3-methylbutanoyl-6-O-alpha-D-glucopyranosyl-beta-D-fructofuranoside, 4-hydroxy-3-methylacetophenone, 5-caffeoylquinic acid (5-CQA), 5-chlorogenic acid (5-CGA), 5-hydroxymethyl-2-furfural, 5-hydroxymethyl-2-furoic acid, acrylamide, alanine, alpha-dicarbonyl compounds, alpha-galactosidase, arabinogalactans, asparagine, benzoic acids, bornesitol, caffeic acid, caffeine, caffeoylquinic acid (CQA), calcium, catechin, catechols, chicoric acid, chlorinated hydrocarbons, chlorogenic acid (CA, CGA), chlorogenic acid lactones, cinnamoylquinides, Coffea arabica, Coffea canephora, Coffea robusta, coffee berry, coffee cherry, coffeeberry, CoffeeSlender®, diacetyl, dicaffeoylquinic acid, dihydrocaffeic acid, dihydroferulic acid, epicatechin, ferulic acid, feruloylquinic acid, furan, galactomannans, gallic acid, glyoxal, green coffee bean extract (GCBE), green coffee extract (GCE), hexanol, hippuric acid, hydrogen peroxide (H2O2), hydroxycinnamates, hydroxycinnamic acid, hydroxyhydroquinone (HHQ), iron, isoferulic acid, lignans, magnesium, Maillard reaction products, mannitol, m-coumaric acid, melanoidins, methylglyoxal, methylxanthine, myo-inositol, nicotinic acid (niacin), N-methylpyridinium, ochratoxin-A (OTA), phenyl ethyl alcohol, phenylpropionic acids, phytochemicals, polyalcohols, polycyclic aromatic hydrocarbons, polyphenols, premelanoidins, protocatechuic acid, quinic acid, quinides, raw coffee, rho-coumaric acid, rho-hydroxybenzoic acid, selenium, sinapic acid, sulfur, Svetol®, tannic acid, tannins, theobromine, theophylline, trigonelline, tryptamine, unroasted coffee, vanillic acid, volatile Maillard reaction products (vMRPs).

Clinical Bottom Line/Effectiveness

Brief Background:

  • "Green coffee" refers to the raw or unroasted seeds (beans) of Coffea fruits (also called coffee berries or coffee cherries). Green coffee beans are cleaned, dried, roasted, ground, and brewed to produce the popular beverage coffee. The main Coffea species used for beverage production are Coffea arabica and Coffea canephora (synonym, Coffea robusta). Coffee contains hundreds of components, each of which may have potential and independent pharmacological effects (1). Coffee is a notable source of caffeine. However, the purported effects of coffee on glycemic control have been attributed to other components in coffee, such as chlorogenic acid, quinides, lignans, and trigonelline, all of which have been shown to improve glucose metabolism in animal studies (1).
  • Chlorogenic acids, a major group of phenolic compounds found in coffee and the active constituents in various weight loss supplements, have been shown to inhibit the glucose-6-phosphatase enzyme system in vitro (2). Glucose-6-phosphatase catalyzes the formation of glucose from the liver and has a pivotal role in blood glucose regulation (3). Thus, it has been surmised that chlorogenic acids in the coffee may be responsible, at least in part, for the reduced risks of glycemic disorders with long-term coffee use. The hypoglycemic effects of chlorogenic acids may also underlie its purported antiobesity effects.
  • Long-term coffee consumption has not been shown to correlate with increased cardiovascular disease incidence; however, studies have linked coffee consumption with increased indicators of cardiovascular risk, such as blood pressure and plasma homocysteine levels (4). Clinical research has also linked high doses of chlorogenic acid with increased homocysteine concentration (5). Caffeine and caffeinated coffee are known to acutely increase blood pressure and potentially increase cardiovascular disease risk, and coffee consumption has been correlated with increased use of antihypertensive drugs (6). However, the hypertensive effects of coffee may be attributed to caffeine, as decaffeinated coffee has not been shown to have the same effects (7). Furthermore, several small clinical trials have demonstrated the hypotensive effects of chlorogenic acids (from green coffee extract) in mild hypertension. The contradictory effects of roasted and raw coffee on blood pressure may be explained in part by hydroxyhydroquinone (HHQ), a product of roasting, which has been shown to inhibit the beneficial effects of chlorogenic acid on blood pressure in hypertensive mice (8), rats (9), and mildly hypertensive women (10). The hypotensive effects of green coffee extract are thought to be due to ferulic acid, a metabolite of 5-caffeoylquinic acid, possibly mediated by muscarinic acetylcholine receptors (11) or nitric oxide (NO)-mediation vasodilation.
  • It is possible that certain factors, such as gender or genetic makeup, may influence an individual's response to chlorogenic acid. One epidemiological study found that coffee consumption was associated with improved insulin sensitivity in women, but not in men (12). Further research is warranted to examine the role of gender, as well as other genetic factors, in short- and long-term chlorogenic acid supplementation.

Dosing/Toxicology

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Precautions/Contraindications

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Interactions

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.

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Mechanism of Action

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History

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Evidence Table

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Evidence Discussion

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Products Studied

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Author Information

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References

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.

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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.