Green coffee

Green Coffee Extract/Drug Interactions:

  • AntibioticsAntibiotics: Green coffee extracts have shown antibacterial effects in some studies (91; 92; 93), but not others (94). Green coffee may interact with antibacterial agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • AnticholinergicsAnticholinergics: The hypotensive effects of ferulic acid, a metabolite of 5-caffeoylquinic acid, were abolished by concurrent administration of the anticholinergic agent atropine sulfate in a rat model of hypertension (11).
  • AntidiabeticsAntidiabetics: Various coffee constituents have shown antidiabetic effects (77; 78). The hypoglycemic effects of caffeine have been demonstrated (79; 80; 82; 81; 82; 83; 84). Chlorogenic acids, quinides, and other cinnamates are also major antidiabetic compounds in green and roasted coffee (2; 85; 86; 84; 87). Magnesium, also found in coffee (95), is also critical for glucose metabolism (96). Thus green coffee may potentially interact with antidiabetic agents, but the nature of this potential interaction is unclear, and evidence is lacking.
  • AntifungalsAntifungals: Epicatechin, which is abundant in green coffee berry pericarp, has been shown to have antifungal effects against Colletotrichum kahawae (97). Green coffee may interact with antifungal agents, but the nature of this potential interaction is unclear, as clinical evidence is lacking.
  • AntihypertensivesAntihypertensives: The hypotensive effects of green coffee extract are thought to be due to ferulic acid, a metabolite of 5-caffeoylquinic acid (11). Green coffee may interact with antihypertensive agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • Anti-inflammatoriesAnti-inflammatories: Several coffee constituents possess anti-inflammatory effects, including caffeine (79) and the diterpenes kahweol and cafestol (98; 99). Green coffee may interact with anti-inflammatory agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • AntilipemicsAntilipemics: The diterpenes found in coffee (cafestol and kahweol) are believed to underlie coffee's ability to raise plasma cholesterol and lipoproteins (100) and may counteract the effects of antilipemic agents. However, evidence of this interaction is unclear. Coffea robusta is reported to contain no kahweol and less cafestol than Coffea arabica (101). Svetol? green coffee extract reportedly does not contain diterpenes (4).
  • AntineoplasticsAntineoplastics: Though green coffee has oxidative and anticarcinogenic effects, certain constituents are potentially carcinogenic or mutagenic. Green coffee plant tannins are potentially carcinogenic (53). Results have been mixed; however, positive mutagenicity has been reported for caffeic acid (40; 39), chlorogenic acid (39), and trigonelline (54). Thus, green coffee may counteract the effects of antimutagenic agents or compound the effects of mutagenic agents; however, evidence for this interaction is lacking
  • Antiobesity agentsAntiobesity agents: In addition to caffeine, chlorogenic acid and quinides found in coffee are thought to promote weight loss (7; 34). Green coffee may interact with antiobesity agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • AntiviralsAntivirals: Green coffee extracts have been shown to have antiviral effects against HIV-1 (102) and herpes simplex virus (103). Green coffee may interact with antiviral agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • AnxiolyticsAnxiolytics: Coffee has been shown to reduce restraint-induced stress; however, this effect was attributed to caffeine and not chlorogenic acid (104). Green coffee may interact with anxiolytic agents, but this potential interaction may depend on the caffeine content.
  • Beta-blockersBeta-blockers: Concurrent use of beta-blocking agents with coffee can result in antagonism of the desired effect of either agent. One case report described anaphylactic shock caused by drinking, which was potentiated by ophthalmic timolol, a beta-adrenergic antagonist; allergy to coffee and the gum arabic coating on roasted coffee was confirmed by skin prick, but green coffee allergy was not specifically tested (90).
  • Calcium saltsCalcium salts: Studies in rats found the solubility of calcium to decrease when coffee (caffeinated or decaffeinated) was mixed into the diet (95).
  • Cholinergic agonistsCholinergic agonists: The hypotensive effects of green coffee extract are thought to be mediated by muscarinic acetylcholine receptors (11). Green coffee may interact with muscarinic agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • Iron saltsIron salts: Polyphenolic compounds found in coffee (namely chlorogenic acids) are potent inhibitors of iron absorption in humans (105); this iron-reducing activity is not affected by caffeine (106). Studies in rats found the solubility of iron to decrease when caffeinated (but not decaffeinated) coffee was mixed in the diet (95).

    • Green Coffee Extract/Herb/Supplement Interactions:

  • AntibacterialsAntibacterials: Green coffee extracts have shown antibacterial effects in some studies (91; 92; 93), but not others (94). Green coffee may interact with antibacterial agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • AnticholinergicsAnticholinergics: The hypotensive effects of ferulic acid, a metabolite of 5-caffeoylquinic acid, were abolished by concurrent administration of the anticholinergic agent atropine sulfate in a rat model of hypertension (11).
  • AntifungalsAntifungals: Epicatechin, which is abundant in green coffee berry pericarp, has been shown to have antifungal effects against Colletotrichum kahawae (97). Green coffee may interact with antifungal herbs and supplements, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • Anti-inflammatoriesAnti-inflammatories: Several coffee constituents possess anti-inflammatory effects, including caffeine (79) and the diterpenes kahweol and cafestol (98; 99). Green coffee may interact with anti-inflammatory herbs and supplements, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • AntilipemicsAntilipemics: The diterpenes found in coffee (cafestol and kahweol) are believed to underlie coffee's ability to raise plasma cholesterol and lipoproteins (100) and may counteract the effects of antilipemic agents. However, evidence of this interaction is unclear. Coffea robusta is reported to contain no kahweol and less cafestol than Coffea arabica (101). Svetol? green coffee extract reportedly does not contain diterpenes (4).
  • AntineoplasticsAntineoplastics: Though green coffee has oxidative and anticarcinogenic effects, certain constituents are potentially carcinogenic or mutagenic. Green coffee plant tannins are potentially carcinogenic (53). Results have been mixed; however, positive mutagenicity has been reported for caffeic acid (40; 39), chlorogenic acid (39), and trigonelline (54). Thus, green coffee may counteract the effects of antimutagenic agents or compound the effects of mutagenic agents; however, evidence for this interaction is lacking.
  • Antiobesity agentsAntiobesity agents: In addition to caffeine, chlorogenic acid and quinides found in coffee are thought to promote weight loss (7; 34). Green coffee may interact with antiobesity herbs and supplements, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • AntiviralsAntivirals: Green coffee extracts have been shown to antiviral effects against HIV-1 (102) and herpes simplex virus (103). Green coffee may interact with antiviral agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • AnxiolyticsAnxiolytics: Coffee has been shown to reduce restraint-induced stress; however, this effect was attributed to caffeine and not chlorogenic acid (104). Green coffee may interact with anxiolytic herbs and supplements, but this potential interaction may depend on the caffeine content.
  • Beta-caroteneBeta-carotene: In mice, the antigenotoxic effects of coffee constituents (namely chlorogenic acid) were enhanced by coadministration of beta-carotene (107).
  • CalciumCalcium: Studies in rats found the solubility of calcium to decrease when coffee (caffeinated or decaffeinated) was mixed into the diet (95).
  • Carcinogenic/oxidative herbs and supplementsCarcinogenic/oxidative herbs and supplements: There is some in vivo and in vitro evidence that green coffee ameliorates the carcinogenic effects of 7,12-dimethylbenz(a)anthracene (DMBA) (108; 109) and H2O2 cells (110). Some studies have been attributed the anticarcinogenic effects to the diterpenes (kahweol and cafestol) found in green coffee (4; 111; 112; 113; 98). However, the diterpene content of green coffee may vary among preparations. The anticarcinogenic effects of chlorogenic acid have also been demonstrated in numerous animal studies (114; 115; 116; 15; 117; 118).
  • CholinergicsCholinergics: The hypotensive effects of green coffee extract are thought to be mediated by muscarinic acetylcholine receptors (11). Green coffee may interact with muscarinic agents, but the nature of this potential interaction is unclear, due to insufficient evidence.
  • Clove oil (eugenol)Clove oil (eugenol): Various dietary constituents may enhance the effects of green coffee constituents. In mice, the antigenotoxic effects of coffee constituents (namely chlorogenic acid) were enhanced by coadministration of eugenol (107).
  • CurcuminCurcumin: In mice, the antigenotoxic effects of coffee constituents (namely chlorogenic acid) were enhanced by coadministration of curcumin (107).
  • CyclodextrinCyclodextrin: The dietary fiber cyclodextrin, which has applications in weight loss products (119; 120; 121), has been shown to complex with chlorogenic acid (122; 123; 124); this may reduce or eliminate the bitter and astringent tastes of chlorogenic acids and other coffee constituents (125).
  • GarlicGarlic: Ingestion of a drink high in chlorogenic acids was shown to reduce the amount of allyl methyl sulfate gas, which causes malodorous breath after garlic ingestion; this effect was attributed to the strong thiol-capturing activity of chlorogenic acids (126).
  • HypoglycemicsHypoglycemics: Various coffee constituents have shown antidiabetic effects (77; 78). The hypoglycemic effects of caffeine have been demonstrated (79; 80; 81; 82; 83; 84). Chlorogenic acids, quinides, and other cinnamates are also major antidiabetic compounds in green and roasted coffee (2; 85; 86; 84; 87). Magnesium, also found in coffee (95), is also critical for glucose metabolism (96). Thus green coffee may potentially interact with hypoglycemic herbs and supplements, but the nature of this potential interaction is unclear, and evidence is lacking.
  • HypotensivesHypotensives: Due to the hypotensive effects demonstrated in clinical trials (19; 20; 18; 33), interactions between green coffee extract and antihypertensive herbs and supplements are theoretically possible. The hypotensive effects of green coffee extract are thought to be due to ferulic acid, a metabolite of 5-caffeoylquinic acid (11).
  • IronIron: Polyphenolic compounds found in coffee (namely chlorogenic acids) are potent inhibitors of iron absorption in humans (105); this iron-reducing activity is not affected by caffeine (106). Studies in rats found the solubility of iron to decrease when caffeinated (but not decaffeinated) coffee was mixed in the diet (95).
  • Milk proteinMilk protein: Biochemical interactions between milk proteins and chlorogenic acid (shown using a biochemical ultrafiltration technique) were slightly disrupted in an in vitro digestion model using the Caco-2 colorectal cell line; however, cosupplementation with milk proteins did not modify the absorption of chlorogenic acid in rats (14).
  • MineralsMinerals: In rats, the bioavailability of certain minerals was altered when coffee was included in the diet (95).
  • ProbioticsProbiotics: Certain gut bacteria (such as bifidobacteria and lactobacilli) have been shown to release bioactive hydroxycinnamates in the human colon (127); thus, the antioxidant and anticarcinogenic properties of hydroxycinnamates (including caffeic, ferulic and p-coumaric acids) found in green coffee extracts may be enhanced by probiotics.
  • Vitamin EVitamin E: In mice, the antigenotoxic effects of coffee constituents (namely chlorogenic acid) were enhanced by coadministration of alpha-tocopherol (vitamin E) (107).

    • Green Coffee Extract/Food Interactions:

  • GeneralGeneral: Various dietary constituents may enhance the effects of green coffee constituents. In mice, the antigenotoxic effects of coffee constituents (namely chlorogenic acid) were enhanced by coadministration of alpha-tocopherol (vitamin E), beta-carotene, curcumin, and eugenol (107).
  • AppleApple: In biochemical experiments, a drink high in chlorogenic acids demonstrated strong thiol-capturing activity in the presence of apple-derived acetone powder; this was suggested to reduce malodorous breath caused by garlic ingestion (126).
  • Cultured and fermented foodsCultured and fermented foods: Human studies have demonstrated that when chlorogenic acid is ingested, roughly 50% is metabolized by colonic bacteria to hippuric acid (128). Certain gut bacteria (such as bifidobacteria and lactobacilli) have been shown to release bioactive hydroxycinnamates from metabolizing chlorogenic acid in the human colon (127); thus, the antioxidant and anticarcinogenic properties of hydroxycinnamates (including caffeic, ferulic and p-coumaric acids) found in green coffee extracts may be enhanced by cultured or fermented foods containing probiotic bacterial strains.
  • CyclodextrinCyclodextrin: The food additive cyclodextrin, a dietary fiber, has been shown to complex with chlorogenic acid (122; 123; 124), which may reduce or eliminate bitter and astringent tastes (125).
  • GarlicGarlic: Ingestion of a drink high in chlorogenic acids was shown to reduce allyl methyl sulfate gas, which causes malodorous breath after garlic ingestion; this effect was attributed to the strong thiol-capturing activity of chlorogenic acids (126).
  • Iron-containing foodsIron-containing foods: Polyphenolic compounds found in coffee (namely chlorogenic acids) are potent inhibitors of iron absorption (105); this iron-reducing activity is not affected by caffeine (106).
  • MilkMilk: Biochemical interactions between milk proteins and chlorogenic acid (shown using a biochemical ultrafiltration technique) were slightly disrupted in an in vitro digestion model using the Caco-2 colorectal cell line; however, cosupplementation with milk proteins did not modify the absorption of chlorogenic acid in rats (14).
  • MineralsMinerals: In rats, the bioavailability of certain minerals was altered when coffee was included in the diet (95).

    • Green Coffee Extract/Lab Interactions:

  • Blood glucoseBlood glucose: Green coffee and its constituents have been demonstrated clinically to lower blood postprandial glycemia (129; 21; 32).
  • Blood homocysteineBlood homocysteine: Coffee drinking has been associated with increased levels of plasma homocysteine,a predictor of risk of cardiovascular disease. This has been shown clinically after administration of chlorogenic acid (5). However, another study found green coffee extract containing chlorogenic acid to slightly lower plasma homocysteine (20).
  • Blood pressureBlood pressure: Green coffee extracts have been shown to reduce blood pressure in several clinical studies (19; 20; 18; 33).