the natural polyphenols found in green coffee beans are a group of hydroxycinnamic acids, the primary ones being chlorogenic, caffeic and ferulic acids. This group of polyphenols has many significant health benefits. Aside from their potent antioxidant activity, the most recently studied benefits pertain to their potential role in carbohydrate metabolism. Chlorogenic Acid specifically is shown to decrease the uptake of glucose in the body and assist in regulating blood glucose levels. What makes their antioxidant properties so unique to other flavonoid and vitamin based compounds is their target impact in the reduction of lipid peroxidation, resulting in significant heart health benefits. These synergistic health characteristics of the chlorogenic acids provide a compound that can contribute added nutritional functionality to formulators. For additional technical information on the health benefits of hydroxycinnamic acids please click on the links below.
Chlorogenic Acid Molecule
Chlorogenic Acid in Carbohydrate Metabolism
G-6-Pase translocase inhibitors may be useful for the reduction of inappropriately high rates of hepatic glucose output often found in non-insulin dependent diabetes (Type II) and obese individuals. The enzyme system glucose-6-phosphatase (G-6-Pase) plays a major role in the homeostatic regulation of blood glucose. It is responsible for the formation of endogenous glucose originating from gluconeogenesis and glycogenolysis. As published in the Archives of Biochemistry and Biophysics, chlorogenic acid was identified as a specific inhibitor of the glucose-6-phosphate translocase component of this enzyme system.
Chlorogenic acid can effectively block the utilization and/or absorption of consumed carbohydrates. Specifically, Glucose-6-phosphate hydrolysis requires the coupled function of at least three integral proteins of the endoplasmic reticulum known as the G-6-Pase system that contain 1) the enzyme, Glucose-6-phosphatase (G-6-Pase) 2) a G-6-P translocase and 3) a transporter translocase. Chlorogenic acid binds to the G-6-P translocase protein, inhibiting its activity. G-6-P hydrolysis is thereby prevented.
Chlorogenic acid inhibits, in a dose dependent fashion, gluconeogenesis and the hepatic glycogenolysis. This is accomplished because chlorogenic acid inhibits, in a competitive way, the enzyme phosphated glucose-6-phosphate in an irreversible fashion and has been proven in animal studies in vitro. In vivo studies by Herling et al. published in the American Journal of Physiology and Biophysics on animal subjects have demonstrated the administration of chlorogenic acid lessens the hyperglycemic peak by over 50% resulting from the glycogenolysis brought about by the administering of glucagen, a hyperglycemiant hormone. The studies also confirmed a reduction in blood glucose levels of 35% and a correlating increase in the intrahepatic concentrations of glucose-6-phosphate and of glycogen.
Additional References
Green Coffee Polyphenols as a Powerful Antioxidant
Antioxidants are a group of compounds that can prevent and delay oxidative damage of the body’s cellular DNA, which may help reduce the risk of cancer and other degenerative diseases. They do this by essentially mopping up free radicals as they are produced within the body from oxidation of the harmful and unwanted substances one inhales, ingests or metabolizes. The specific flavonoid compounds in green coffee beans have been shown to be potent inhibitors of mutagenesis and carcinogenesis of polycylic aromatic hydrocarbons. The role of these acids in the prevention of genotoxicity in animal tissues has also been demonstrated by the acids’ ability to inhibit several tumor promoting and carcinogenic compounds (Tanaka, et al. 1993; Huang, et al. 1988).
One of the most exciting roles for these compounds is as a powerful heart healthy antioxidant. The antioxidant ability of hydroxycinnamic acids to increase the resistance of low density lipoprotein (LDL) to cholesterol oxidation and lipid peroxidation independent of other flavonoid constituents has also been confirmed (Nardini, et al. 1995; Castelluccio, et al. 1995). Oxygen free radicals have been implicated in chronic disease, but particularly atherosclerotic cardiovascular disease. Oxidation of LDL cholesterol may increase the risk of atherosclerosis.
How does LDL oxidation increase the risk of atherosclerosis? Native LDL undergoes oxidative modification by intracellular oxygen free radicals, probably generated by cellular lipo-oxygenesis. The initiating event is the peroxidation of polyunsaturated lipids in the LDL molecule. These free radicals quickly propagate, attacking susceptible polyunsaturated fatty acids in the LDL. Reactive substances from the LDL particle include malonaldehyde, lipoic peroxides and lysophosphatides. The LDL is modified so it is not recognized by the LDL receptor but only by the scavenger receptor found in the macrophages. Oxidized LDL is taken up by the subendothelial macrophage that undergoes transformation into the lipid-laden foam cell. Oxidized LDL has atherogenic properties which leads to increasing numbers of macrophages in the subendothelial space; these macrophages themselves oxidize LDL and also take up oxidized LDL through receptors to become foam cells, accelerating the development of the atherosclerotic streak.
The class of polyphenolic compounds in coffee beans, such as the chlorogenic and caffeic acids, have been shown to not only reduce LDL oxidation in vivo at a much higher level than other plant based compounds but also have a compounding effect in lowering total triglycerides.
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