Green Coffee Bean Extract
Green Coffee bean Extract comes from the unroasted coffee beans of the Coffea plant, which contains a number of polyphenolic compounds including Chlorogenic Acid. These are known to possess potent antioxidant activity and appear to be beneficial for weight loss. It's known that roasting coffee beans significantly reduces the levels of chlorogenic acid and antioxidant activity and therefore green coffee beans are a significantly better source of antioxidants including chlorogenic acid than roasted coffee beans. Recently green coffee bean extract has been marketed as a potential weight loss supplements including “Coffee Slender”, and “Svetol”. Green coffee bean extract appears to have a number of beneficial effects including: a significant weight loss effect, protection against the build up of visceral fat, decreases blood glucose levels, possesses hypotensive (blood pressure lowering) properties.
The main constituents of green coffee bean extract are chlorogenic acid (~27%) and caffeine (~10%) (Shimoda et al 2006). Green coffee extract is now available with less than 2% caffeine (Svetol®). It's known that roasting coffee beans significantly decreases levels of important antioxidant like chlorogenic acid (Del Castillo et al., 2000) and therefore green coffee beans provide a better soure of chlorogenic acid and other polyphenolic antioxidants than roasted coffee beans.
Green coffee bean extract and weight loss
Green coffee bean extract appears to be an effective weight loss supplement (Vinson et al., 2012; Onakpoya et al., 2011; Shimoda et al 2006). Research in mice found that green coffee bean extract was able to suppress gains in both body weight and visceral fat - the fat that builds up within the abdominal cavity and surrounds important internal organs like the heart, liver, kidneys and pancreas - accumulation (Shimoda et al 2006). Protection against the build up of visceral fat is important since increased visceral fat is known to increase the risk of cardiovascular disease, metabolic disturbances, type II diabetes, and some cancers. The researchers suggested that it was a combination of the compounds in green coffee bean extract (caffeine, chlorogenic acid and other polyphenolic compounds) that worked synergistically to suppress the gains in body weight gain and prevent visceral fat accumulation in the mice (Shimoda et al 2006). The researchers concluded that caffeine within green coffee bean extract suppresses fat absorption whereas the cholorogenic acid and other polyphenolic compounds were invloved in enhancing fat metabolism within the liver.
More recently a meta-analysis of current research involving green coffee extract found that green coffee extract resulted in significant changes in bodyweight when compared with a placebo (Onakpoya et al., 2010). The researchers concluded that "The evidence from RCTs [Randomaly controlled trials] seems to indicate that the intake of GCE [green coffee extract] can promote weight loss." (Onakpoya et al., 2010).
A recent human study using 700-1050mg of green coffee bean extract demonstrated significant weight loss, with an average weight loss of ~ 10% of bodyweight (Vinson et al., 2012) over a 22 week period. The greatest weight loss was found to occur with the highest dose of green coffee bean extract. The significant weight loss effects associated with green coffee extract appear to be due, in a large part, to the pressence of chlorogenic acid. Research has shown that chlorogenic acid can decrease fasting blood glucose levels and stimulate glucose transport in skeletal muscles (Khang Wei Ong 2012) and appears to significantly lower bodyweight (Cho et al., 2010). Chlorogenic acid may also inhibit hepatic glucose-6-phosphatase (Arion et al., 1997), which may help to limit glucose production within the liver.
Green coffee extract possesses anti-hypertensive properties
Green coffee bean extract appears to possess hypotensive (blood pressure lowering) properties (Watanabe et al., 2006; Kozuma et al., 2005; Suzuki et al., 2002). Research in animals found that green coffee bean extract possessed hypotensive properties in spontaneously hypertensive rats (Suzuki et al., 2002). In humans it appears to lower blood pressure in people with mild hypertension (Kozuma et al., 2005; Watanabe et al., 2006). Green coffee bean extract has also been shown to improve vasoreactivity - the contraction of blood vessels in response to stimulation (Ochiai et al., 2004).
- Green coffee extract has a significant weight loss effect
- It protects against the accumulation of visceral fat - the fat that builds up around and in-between internal organs
- Has a hypotensive (blood pressure lowering) effect
- Improves vasoreactivity
- Can decrease blood glucose levels
- Appears to enhance fat metabolism within the liver
- Possesses strong antioxidant properties
Green coffee extract appears to be beneficial for people looking for a weight loss supplement. In addition to the weight loss benefits green coffee extract appears to have potential health benefits including a hypotensive effect (blood pressure lowering effect), improves vasoreactivity (contraction of blood vessels following stimulation), protection against the accumulation of visceral fat (fat that builds up around and between internal organs), and antioxidant activity.
Early research suggests that green coffee bean extract may be an effective weight loss supplement and appears to protect against the accumulation of visceral fat between and around important organs such as the heart and liver. Green coffee extract also appears to have a hypotensive effect and improves vasoreactivity.
Reasearch suggests around 700-1050mg of green coffee extract may be required for weight loss. Green coffee extract appears to exert its hypotensive effects at lower doses - research using doses as low as 93mg, 140mg & 185mg have all had hypotensive effects (Watanabe et al., 2006; Kozuma et al., 2005).
Green coffee extract appears to be safe and free of adverse side effects (Vinson et al., 2012; Watanabe et al., 2006; Kozuma et al., 2005;).
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Cho AS, Jeon SM, Kim MJ, Yeo J, Seo KI, Choi MS, Lee MK. (2010) Chlorogenic acid exhibits anti-obesity property and improves lipid metabolism in high-fat diet-induced-obese mice.Food Chem Toxicol. 2010 Mar;48(3):937-43. Epub 2010 Jan 12.
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Khang Wei Ong, Annie Hsu, Benny Kwong Huat Tan (2012) Chlorogenic Acid Stimulates Glucose Transport in Skeletal Muscle via AMPK Activation: A Contributor to the Beneficial Effects of Coffee on Diabetes. PLoS ONE: Research Article, published 07 Mar 2012
Kozuma K, Tsuchiya S, Kohori J, Hase T, Tokimitsu I. (2005) Antihypertensive effect of green coffee bean extract on mildly hypertensive subjects. Hypertens Res. 2005 Sep;28(9):711-8.
Igho Onakpoya, Rohini Terry, Edzard Ernst (2010) The Use of Green Coffee Extract as a Weight Loss Supplement: A Systematic Review and Meta-Analysis of Randomised Clinical Trials. Gastroenterol Res Pract. 2011; 2011: 382852. Published online 2010 August 31.
Ochiai R, Jokura H, Suzuki A, Tokimitsu I, Ohishi M, Komai N, Rakugi H, Ogihara T. (2004) Green coffee bean extract improves human vasoreactivity. Hypertens Res. 2004 Oct;27(10):731-7.
Hiroshi Shimoda, Emi Seki, Michio Aitani (2006) Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice. BMC Complementary and Alternative Medicine 2006, 6:9 (17 March 2006)
Suzuki A, Kagawa D, Ochiai R, Tokimitsu I, Saito I. (2002) Green coffee bean extract and its metabolites have a hypotensive effect in spontaneously hypertensive rats. Hypertens Res. 2002 Jan;25(1):99-107.
Vinson JA, Burnham BR, Nagendran MV. (2012) Randomized, double-blind, placebo-controlled, linear dose, crossover study to evaluate the efficacy and safety of a green coffee bean extract in overweight subjects. Diabetes Metab Syndr Obes. 2012;5:21-7. Epub 2012 Jan 18.
Watanabe T, Arai Y, Mitsui Y, Kusaura T, Okawa W, Kajihara Y, Saito I. (2006) The blood pressure-lowering effect and safety of chlorogenic acid from green coffee bean extract in essential hypertension. Clin Exp Hypertens. 2006 Jul;28(5):439-49.