Background
- "Green coffee" refers to the raw, unroasted seeds (beans) of Coffea fruits. 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 is a popular source of caffeine. However, it also contains many other components that are believed to have health benefits, such as lowering blood sugar levels. These components include chlorogenic acid, quinides, lignans, and trigonelline.
- Studies suggest that caffeinated coffee consumption may increase blood pressure and potentially increase the risk of heart disease. However, these results were not found to be true of decaffeinated coffee, and some trials found that chlorogenic acid may actually lower blood pressure. Researchers believe that the differing effects of roasted and raw coffee are due to a compound called hydroxyhydroquinone (HHQ), which is created from the roasting process and may block the beneficial effects of chlorogenic acid on blood pressure.
- Scientists believe that genes and gender may play a role in determining how people respond to chlorogenic acid. One study found that coffee consumption led to better insulin sensitivity in women, but not in men. However, further research is needed in order to better understand these findings.
References
- Agardh EE, Carlsson S, Ahlbom A, et al. Coffee consumption, type 2 diabetes and impaired glucose tolerance in Swedish men and women. J.Intern.Med. 2004;255(6):645-652. View Abstract
- Arion WJ, Canfield WK, Ramos FC, et al. Chlorogenic acid and hydroxynitrobenzaldehyde: new inhibitors of hepatic glucose 6-phosphatase. Arch.Biochem.Biophys. 3-15-1997;339(2):315-322. View Abstract
- Dupas C, Marsset, Baglieri A, et al. Chlorogenic acid is poorly absorbed, independently of the food matrix: A Caco-2 cells and rat chronic absorption study. Mol.Nutr.Food Res. 2006;50(11):1053-1060. View Abstract
- Greenberg JA, Boozer CN, and Geliebter A. Coffee, diabetes, and weight control. Am.J.Clin.Nutr. 2006;84(4):682-693. View Abstract
- Herling AW, Burger HJ, Schwab D, et al. Pharmacodynamic profile of a novel inhibitor of the hepatic glucose-6-phosphatase system. Am.J.Physiol 1998;274(6 Pt 1):G1087-G1093. View Abstract
- Higdon JV and Frei B. Coffee and health: a review of recent human research. Crit Rev.Food Sci.Nutr. 2006;46(2):101-123. View Abstract
- Hu G, Jousilahti P, Nissinen A, et al. Coffee consumption and the incidence of antihypertensive drug treatment in Finnish men and women. Am.J.Clin.Nutr. 2007;86(2):457-464. View Abstract
- Mori H, Kawabata K, Matsunaga K, et al. Chemopreventive effects of coffee bean and rice constituents on colorectal carcinogenesis. Biofactors 2000;12(1-4):101-105. View Abstract
- Namba T and Matsuse T. [A historical study of coffee in Japanese and Asian countries: focusing the medicinal uses in Asian traditional medicines]. Yakushigaku.Zasshi 2002;37(1):65-75. View Abstract
- Olthof MR, Hollman PC, Zock PL, at al. Consumption of high doses of chlorogenic acid, present in coffee, or of black tea increases plasma total homocysteine concentrations in humans. Am.J.Clin.Nutr. 2001;73(3):532-538. View Abstract
- Suzuki A, Fujii A, Jokura H, et al. Hydroxyhydroquinone interferes with the chlorogenic acid-induced restoration of endothelial function in spontaneously hypertensive rats. Am.J.Hypertens. 2008;21(1):23-27. View Abstract
- Suzuki A, Fujii A, Yamamoto N, et al. Improvement of hypertension and vascular dysfunction by hydroxyhydroquinone-free coffee in a genetic model of hypertension. FEBS Lett. 4-17-2006;580(9):2317-2322. View Abstract
- Suzuki A, Kagawa D, Ochiai R, et al. Green coffee bean extract and its metabolites have a hypotensive effect in spontaneously hypertensive rats. Hypertens.Res. 2002;25(1):99-107. View Abstract
- van Dam RM and Hu FB. Coffee consumption and risk of type 2 diabetes: a systematic review. JAMA 7-6-2005;294(1):97-104. View Abstract
- Yamaguchi T, Chikama A, Mori K, et al. Hydroxyhydroquinone-free coffee: a double-blind, randomized controlled dose-response study of blood pressure. Nutr.Metab Cardiovasc.Dis. 2008;18(6):408-414. View Abstract