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Green Coffee Bean
+1 (Slight Evidence)
+1 (Slight Evidence)
- The active ingredient in green (unroasted) coffee bean is called chlorogenic acid. Multiple recent (2011-2012), small, randomized, controlled, double-blinded trials of up to 1 gram of chlorogenic acid have demonstrated weight loss, decreased blood pressure independent of the weight loss, and inhibition of glucose (sugar) production in the liver.
- The committee rated this product conservatively with a 1+ because we felt that a larger randomized trial with similar results would be required for a higher rating.
- Of all the supplements we have evaluated for weight loss, green coffee bean is the only consistent choice for this indication. Consistent results from multiple small studies show a weight loss benefit that, in our opinion, outweighs the rare –though real – possibility of increased homocysteine levels at high doses of chlorogenic acid.
- While green coffee bean extract does have a beneficial effect on blood vessels, there is a limit. High coffee intake is associated with increased levels of homocysteine, which may increase the risk of cardiovascular disease. Research showed that drinkers of approximately 6 cups or more (1.5 liters) of coffee/day increased their homocysteine levels.
- People with certain types of DNA are more sensitive to caffeine than others. High levels of caffeine have been known to cause anxiety, agitation, even abnormal heart rhythms. Since most of us have not been tested to find out if we are susceptible, make sure you do not have these effects before increasing your coffee intake.
- The FDA reported at least one green coffee bean product containing hidden sibutramine, a weight-loss product with harmful effects to blood pressure and heart rate. This is why we choose Wellness Store suppliers so carefully.
* *ADVISORY* *
In addition to the supplement, smaller amounts of chlorogenic acid are also present in brewed coffee, which contains about 2 grams of chlorogenic acid per 1.5 liters, equivalent to just over six 8-ounce cups per day. Admittedly, that’s a lot of coffee. If you decide to try a supplement but still drink coffee, do the math and be careful to stay under 1 gram per day.
DOSAGE:Do not exceed the recommended maximum of 1 gram/day.
CONCLUSION:We conclude that while green coffee bean shows promise for treating weight loss and hypertension, there is not enough evidence for us to recommend its use for this indication. If you do elect to try it, please discuss your decision with your doctor, and observe carefully for any changes to your health.
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Kozuma, K. et al. Antihypertensive Effect of Green Coffee Bean Extract on Mildly Hypertensive Subjects. Hypertens Res (2005) 28(9): 711-718
Bakuradze, T. et al. Antioxidant-rich coffee reduces DNA damage, elevates glutathione status and contributes to weight control: Results from an intervention study. Mol. Nutr. Food Res. (2011) 55, 793-797
Agardh, E.E. et al. Coffee consumption, type 2 diabetes and impaired glucose tolerance in Swedish men and women. Journal of Internal Medicine (2004) 255: 645-652
Olthof, M. et al. Consumption of high doses of chlorogenic acid, present in coffee, or of black tea increases plasma total homocysteine concentrations in humans. The American Journal of Clinical Nutrition (2001) 73: 532-538
Ochiai, R. et al. Green Coffee Bean Extract Improves Human Vasoreactivity. Hypertens Res (2004) 27(10): 731-737
Yamaguchi, T. et al. Hydroxyhydroquinone-free coffee: A double-blind, randomized controlled dose-response study of blood pressure. Nutrition, Metabolism & Cardiovascular Diseases (2008) 18, 408-414
Shimoda, H. et al. Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice. BMC Complementary and Alternative Medicine (2006) 6:9
Vinson, J. et al. 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, Metabolic Syndrome and Obesity: Targets and Therapy (2012) 5: 21-27
Wantanabe, T. et al. The Blood Pressure-Lowering Effect and Safety of Chlorogenic Acid from Green Coffee Bean Extract in Essential Hypertension. Clinical and Experimental Hypertension (2006) 28: 439-449
Onakpoya, I. et al. The Use of Green Coffee Extract as a Weight Loss Supplement: A Systematic Review and Meta-Analysis of Randomised Clinical Trials. Gastroenterology Research and Practice (2011) 1-6