As endorsed by Dr. Oz on his TV show in 2012, green coffee bean’s market demand began to rise up rapidly. With mountains of health supplements out in the market claiming authenticity when it comes to weight loss, it has also gained a number of raised eyebrows and critics from the community.
Before believing the advertisements from suppliers, here is a thorough review of green coffee bean extract:
Basically, green coffee beans are just like any ordinary coffee beans out in the market, only without undergoing the roasting process which is responsible for the brown color of the usual coffee beans.
Raw coffee beans, exhibiting a green shade, contains high amount of caffeine and antioxidants including a compound called chlorogenic acid. This substance when extracted from coffee beans is believed to play a big part on the weight loss process. When you see a “green coffee bean extract” written on the supplement, this immediately refers to chlorogenic acid since roasted coffee beans lose this important substance during the process.
Aside from raw coffee beans, chlorogenic acid could also be found on sunflower seeds, bamboo, prunes, peaches, blueberries and teas.
Researchers claim that glucose-6-phosphatase is disrupted by chlorogenic acid. The former enzyme is actively involved in the body’s glucose management. On the other hand, chlorogenic acid works effectively with caffeine when it comes to boosting the metabolism up to 3-11%. Absorption of carbohydrates in the digestive tract and blood glucose levels are reduced in some studies conducted on humans.
For non-human studies involving the use of laboratory animals like mice, the body weight, fat absorption and stored fats on the liver are all reduced. Adiponectin’s function is also enhanced as an intense fat burning hormone. Risk factors for heart diseases are also kept afar with regulated cholesterol and triglyceride levels conducted on mice.
More Studies on Humans
A randomized controlled trial conducted on 30 individuals for 12 weeks was performed to distinguish weight loss properties of instant coffee and another with 200 mg green coffee extract. The participants were not asked to change their diet and lifestyle during the entire course of study. Results showed a 3.6% decrease on body fats of green coffee extract cluster while the instant coffee cluster only developed a 0.7% decrease.
More than 2,000 studies have been done on green coffee bean extracts. However, the list was trimmed down to 3 with methodologies found to be valid and reliable. These 3 studies covered 143 participants.
Studies focused on glucose absorption and effect on long-term obese people; independent market study on chlorogenic acid effect on fat mass ratio of participants. In general, the three studies showed related results of green coffee bean extract’s ability to contribute in weight loss. Yet, the researchers did not exclude the fact and reality that the extract’s outcome is considered “moderate” and the clinical relevance is not really assured. The weight loss effect is not as drastic as the manufacturers claim.
Due to lack of solid evidence even from previous studies, Applied Food Sciences decided to fund a study on green coffee bean extract in 2012. It was a randomized control research published in the journal “Diabetes Metabolic Syndrome and Obesity”. Sixteen obese men and women in India underwent 22 weeks of participation to investigate the effects of GCA, a green coffee bean extract supplement.
In summary, positive results were obtained after the study wherein the participants lost around 4 lbs in a matter of 6 weeks. In spite of that, the study has been retracted in 2014 due to the lack of verification of the evidence from the researchers. Turned out, the names of researchers published on the paper were not the actual people who conducted the research in India. This is doubtful in the first place since the Applied Food Sciences facility is based in Texas and companies who fund research projects for their endorsed products are sometimes biased.
Dosage and Side Effects
According to more than a thousand studies, green coffee bean extract is safe to use and side-effect free. Nevertheless, few participants backed out after several intakes due to severe headache and urinary tract infection. Since the study where alleged side effects took place is too small to provide solid evidence, the side effects are disregarded and considered only as a coincidence.
Similar to usual roasted coffee, green coffee bean contains high amounts of caffeine that could elicit various health concerns like anxiety and rapid heartbeat. It also develops a laxative effect on the drinker that may induce loose bowel movement when not taken moderately.
Allergic reactions were also noted on some individuals while chlorogenic acid was not clearly proven to be safe for expectant and breastfeeding mothers as well as children.
Recommended dosage has not been established but the researchers used dosages of 120-300 mg of chlorogenic acid. This depends on the chlorogenic acid content of the manufactured supplement wherein the dosage could range from 240-3000 mg daily.
Precaution and Conclusion
Proven by a number of studies, green coffee bean extract is certainly helpful in weight loss accompanied by benefits concerning glucose and blood pressure. However, the studies were focused on short-term effects, small control group and even sponsored by the manufacturers of chlorogenic supplements. Most are done on test animals and not tested on humans.
Healthy obese individuals without complicated diseases such as diabetes, high blood and cardiac abnormalities took part on the studies. People in this group who consider trying chlorogenic health supplements should consult their attending physician first.
One study using mice reported lowered blood pressures. Whether this also shows similar results to humans, further research and extreme precautions should be considered for people who regularly take medications for blood pressure.
At the present, the manufacturer of Svetol® supplement is among the companies who provided a solid research foundation based on humans. Though the study is still a little disbelieving, the initial findings were promising and somewhat supportive. More advanced studies aiming for long-term effects on a bigger population is recommended.