Green coffee beans are simply unroasted coffee beans, meaning they are completely raw. Green coffee beans contain a compound called chlorogenic acids (CGA) which are easily digestible in humans. These acids are mostly destroyed during the coffee roasting process.
CGAs are being studied for their antioxidant and anti-inflammatory qualities as well as a tool to reduce the risk of type 2 diabetes, Alzheimer’s disease, and cardiovascular disease. In one study, patients took 500mg of green coffee extract daily or a placebo for three months. There was a significant change in overall body fat, and it also seemed to improve serum lipid markers. In those with metabolic syndrome, one small study found green bean extract lowered insulin resistance, systolic blood pressure, and waist circumference.
This supplement is generally well-tolerated. If you are sensitive to caffeine, you should refrain from using green coffee beans as a supplement unless it is decaffeinated. Green coffee bean extract is not recommended for those who have osteopenia or osteoporosis as it may interfere with calcium if taken long-term. It’s generally consumed as an extract though the green beans can be purchased and used to make a very mild, almost tea-like, brew. As always, consult with your healthcare practitioner before making any lifestyle or supplement changes.
Resources:
Farah, Adriana, et al. 2008. “Chlorogenic Acids from Green Coffee Extract are Highly Bioavailable in Humans.” The Journal of Nutrition; 138(12): 2309-15. doi:10.3945/jn.108.095554
Roshan, Hanieh, et al. 2018. “Effects of Green Coffee Extract Supplementation on Anthropometric Indices, Glycaemic Control, Blood Pressure, Lipid Profile, Insulin Resistance and Appetite in Patients with the Metabolic Syndrome: A Randomized Clinical Trial.” The British Journal of Nutrition; 119(3): 250-258. doi:10.1017/S0007114517003439
Sudeep, H V, and K Shyam Prasad. 2021. “Supplementation of Green Coffee Bean Extract in Healthy Overweight Subjects Increases Lean Mass/fat Mass Ratio: A Randomized, Double-blind Clinical Study.” SAGE Open Medicine; 9: 20503121211002590. doi:10.1177/20503121211002590