Top 5 In-Depth Studies Review on Green Coffee Extract for its Effect on Weight Loss


Green coffee extract (GCE), derived from unroasted coffee beans, has gained popularity as a weight loss supplement. It is rich in chlorogenic acids, compounds believed to have weight loss and health benefits.

 

Mechanisms of Action

The proposed mechanisms through which green coffee extract promotes weight loss include:

  • Inhibition of Fat Absorption: Chlorogenic acids in GCE are thought to inhibit the enzyme lipase, reducing fat absorption in the intestines.
  • Enhanced Fat Metabolism: GCE may enhance fat metabolism by increasing the activity of enzymes involved in fat oxidation.
  • Reduction of Glucose Absorption: Chlorogenic acids may reduce the absorption of glucose in the intestines, lowering blood sugar levels and reducing the storage of fat.
  • Improved Insulin Sensitivity: Some studies suggest that GCE can improve insulin sensitivity, which may help regulate blood sugar levels and reduce fat storage.

 

  1. Study on Overweight Adults:

    • Reference: Vinson, J. A., Burnham, B. R., & Nagendran, M. V. (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, Metabolic Syndrome and Obesity: Targets and Therapy, 5, 21-27.
    • Summary: In this study, 16 overweight adults were given green coffee extract (GCA) at doses of 700 mg and 1050 mg daily for 12 weeks. The study found that participants lost an average of 8 kg (approximately 17.5 pounds), a significant reduction in body weight. The body mass index (BMI) and percentage body fat of the participants also showed significant decreases. No side effects were reported, suggesting GCE may be a safe and effective weight loss supplement.
  2. Study on Pre-obesity:

    • Reference: Thom, E. (2007). The effect of chlorogenic acid enriched coffee on glucose absorption in healthy volunteers and its effect on body mass when used long-term in overweight and obese people. Journal of International Medical Research, 35(6), 900-908.
    • Summary: This study involved 30 overweight volunteers who were given chlorogenic acid-enriched coffee for 12 weeks. The results showed a significant reduction in body weight, with an average weight loss of 5.4 kg (approximately 11.9 pounds). The study also found improvements in glucose absorption, suggesting potential benefits for both weight loss and glycemic control.
  3. Meta-Analysis:

    • Reference: Onakpoya, I. J., Terry, R., & Ernst, E. (2011). The use of green coffee extract as a weight loss supplement: a systematic review and meta-analysis of randomized clinical trials. Gastroenterology Research and Practice, 2011, 382852.
    • Summary: This meta-analysis reviewed three randomized clinical trials involving a total of 142 participants. The analysis concluded that green coffee extract could promote weight loss, with participants losing an average of 2.47 kg (approximately 5.4 pounds) more than those taking a placebo. 
  4. Study on Weight Reduction in Japanese Adults:

    • Reference: Watanabe, T., Arai, Y., Mitsui, Y., Kusaura, T., Okawa, W., Kajihara, Y., & Saito, I. (2009). The blood pressure-lowering effect and safety of chlorogenic acid from green coffee bean extract in essential hypertension. Clinical and Experimental Hypertension, 31(4), 342-354.
    • Summary: In this study, Japanese adults with mild hypertension were given green coffee bean extract for 12 weeks. The results showed a significant reduction in body weight, BMI, and waist circumference. Additionally, there was a significant decrease in blood pressure, indicating potential cardiovascular benefits of GCE.
  5. Study on Obese Women:

    • Reference: Shimoda, H., Seki, E., & Aitani, M. (2006). Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice. BMC Complementary and Alternative Medicine, 6, 9.
    • Summary: Although this study was conducted on mice, it provides insights relevant to human weight loss. Mice given green coffee bean extract showed significant reductions in body weight and fat accumulation. This study supports the potential mechanisms by which GCE may promote weight loss, including inhibition of fat absorption and enhancement of fat metabolism.