Green Coffee Bean Extract health benefit and side effects - does it help with weight loss?

Green Coffee Bean Extract health benefit and side effects - does it help with weight loss?

Green coffee bean extract is a new ingredient on the market. It has strong anti-oxidant properties similar to other natural anti-oxidants like green tea and grape seed extract. These beans have polyphenols which act to help reduce free oxygen radicals in the body (in other words acting as good antioxidants). Green coffee bean extract is sometimes standardized to 30 to 50% chlorogenic acid, a compound present in coffee which has long been known for its beneficial properties.

   Boiled coffee drinks contain cafestol which is associated with the negative effects of using coffee as a stimulant, this is not present in green coffee beans or the extract.
   This natural supplement has been mentioned on the  Dr. Oz TV program several times as a potential fat burner that helps with weight loss. Is this claim true?
Availability by herb and vitamin suppliers
Green coffee bean is sold in a variety of extracts usually from 30 percent to 50 percent chlorogenic acid concentration. 

Buy Green Coffee Extract pills, high quality
Research and benefitAlthough this supplement has been promoted as a weight loss pill, there is only limited human research regarding this potential benefit. If you truly wish to shed some pounds, a comprehensive dietary and lifestyle approach is necessary as mentioned in this article on natural weight loss
Review of studies regarding its influence on body weight
Diabetes Metabolic Syndrome Obesity 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.
Department, University of Scranton, Scranton, PA, USA.
A 22-week crossover study was conducted to examine the efficacy and safety of a commercial green coffee extract product GCA™ at reducing weight and body mass in 16 overweight adults. Subjects received high-dose GCA (1050 mg), low-dose GCA (700 mg), or placebo in separate six-week treatment periods followed by two-week washout periods to reduce any influence of preceding treatment. Significant reductions were observed in body weight (-8 ± 2.3 kg), body mass index, and percent body fat, but with no significant changes to diet over the course of the study. The results suggest that GCA may be an effective nutraceutical in reducing weight in preobese adults, and may be an inexpensive means of preventing obesity in overweight adults.
BMC Complement Altern Med. 2006. Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice.
High blood pressure benefit
Perhaps it may have some benefit in lowering blood pressure, but certainly more studies are needed to confirm initial findings.
Clin Exp Hypertens. 2006. The blood pressure-lowering effect and safety of chlorogenic acid from green coffee bean extract in essential hypertension.
Health Care Products Laboratories, Kao Corporation, Tokyo, Japan.
Chlorogenic acids (CGA) in green coffee bean extract (GCE) reduce blood pressure in spontaneously hypertensive rats and humans. The authors examined the blood pressure-lowering effect and safety of CGA in patients with mild hypertension through a placebo-controlled, randomized clinical trial. Subjects were randomized to receive treatment with CGA (140 mg/day) from GCE or placebo. Blood pressure, pulse rate, body mass index, routine blood test, hematochemistry, urinalysis, and subjective symptoms were recorded throughout the study. In the CGA group, but not the placebo group, blood pressure (systolic and diastolic) decreased significantly during the ingestion period. There was no difference in body mass index and pulse rate between groups, nor were there any apparent side effects. Thus, CGA from GCE is effective in decreasing blood pressure and safe for patients with mild hypertension.
Hypertens Res. 2005. Antihypertensive effect of green coffee bean extract on mildly hypertensive subjects.
Improved blood vessel action, circulation
Green coffee bean extract improves human vasoreactivity.
Hypertension Research. 2004.
Green coffee bean extract contains chlorogenic acid as a major phenolic compound, and it in turn contains ferulic acid as a metabolic component that acts on nitric oxide (NO) derived from the vascular endothelium. In this study, the effects of green coffee bean extract on blood vessels were evaluated in healthy males. The subjects were 20 healthy males with reduced vasodilation responses measured by strain gauge plethysmograms (SPG) to ischemic reactive hyperemia. Of the 20 subjects, 10 (mean age, 37.2 years) ingested a test drink containing green coffee bean extract (chlorogenic acid 140 mg/day), and the other 10 (mean age, 35 years) ingested a placebo drink for 4 months. During the ingestion period, SPG, pulse wave velocity (PWV), and serum biochemical parameters were measured, and acceleration plethysmograms (APG) were taken. The reactive hyperemia ratio (RHR) in the test drink group began to increase after ingestion for 1 month and was significantly higher than that in the placebo group after ingestion for 3 months and 4 months. In addition, after ingestion for 4 months, the test drink group showed a significant decrease in the plasma total homocysteine level compared with the pre-ingestion level. However, there were no significant differences in PWV or APG between the test drink group and the placebo drink group. The improvement in RHR after ingestion of a drink containing GCE suggested an improvement in vasoreactivity by this component.
Diabetes and blood sugarDietary supplementation with decaffeinated green coffee improves diet-induced insulin resistance and brain energy metabolism in mice. Nutr Neurosci. 2012.
What do the beans contain?
Polyphenols including chlorogenic acids (caffeoylquinic acids and dicaffeoylquinic acids). Chlorogenic acids are cinnamic acid derivatives with biological effects mostly related to their antioxidant and antiinflammatory activities. Caffeoylquinic acids and dicaffeoylquinic acids are the main chlorogenic acids found in nature. Contains caffeine (I think the amount of caffeine is small but I am not sure yet) which has positive and negative attributes depending on dosage used, timing, and frequency.
Green coffee bean extract is made from the green beans of the coffea Arabica plant. There are two types of coffee plants, arabica and robusta... the arabica is higher in quality and higher in chlorogenic and caffeic acids, two primary compounds responsible for anti-oxidant activity.

Is coffee a functional food?
The worldwide use of coffee for social engagement, leisure, enhancement of work performance and well-being is widely recognized. Depending on the quantities consumed, it can affect the intake of some minerals (K, Mg, Mn, Cr), niacin and antioxidant substances. Epidemiological and experimental studies have shown positive effects of regular coffee-drinking on various aspects of health, such as psychoactive responses (alertness, mood change), neurological (Alzheimer's and Parkinson's diseases) and metabolic disorders (diabetes, gallstones, liver cirrhosis),  increase the effectiveness of pain killers, especially for migraine medications, and gonad and liver function. Despite this, most reviews do not mention coffee as fulfilling the criteria for a functional food. Unlike other functional foods that act on a defined population with a special effect, the wide use of coffee-drinking impacts a broad demographic (from children to the elderly), with a wide spectrum of health benefits. However, there is a down side to coffee drinking. It can cause anxiety and blood pressure problems, and it could also cause or aggravate heart rhythm abnormalities. Hence, it is possible to claim that coffee, when limited to one cup a day could be considered a functional food, but not when 3 or more cups are drank a day, particularly if the coffee is ingested later in the day and causes insomnia.