I got another call today asking about Green Coffee Bean extract (GCE) and weight loss. Time to look at the evidence.
Coffee is one of those substances that is often in the news. Sometimes the news is good, sometimes it’s bad and it all depends om what the researchers are looking for. Pharmaceutically speaking, coffee is a complex substance. Today Green Coffee Bean extract is getting lots of attention due to a chemical called cholorgenic acid. Cholorgenic acid is linked with improvement in blood sugar (glucose) and serum lipids, like cholesterol and triglycerides. The acids are thought to work by decreasing glucose absorption from the intestine. If true these are changes that could improve metabolic health overall and specifically help individuals lose desired fat weight.
ASSESSING THE STUDIES
One study out of Finland published in 2007 shows just that. Of the 30 volunteers, the 15 who consumed a coffee beverage spiked with extra cholorgenic acid showed markedly more fat loss over the 12 week study. The test subjects lost an average of 8 pounds of weight (80% fat weight) when using the spiked beverage versus the 1.5 pounds of weight loss observed in the control group drinking regular instant coffee. The daily dose of cholorgenic acid (Coffee Slender in this study) was not stated, but the standard dose of Coffee Slender was noted as 11 g. News like this get everyone’s attention, but one study is just one study. As I read the results my first question was what happened to the volunteer’s diets during the study? There is no documentation, but the subjects were told “don’t change anything”.
More recently, another study was published, this one a randomized, double-blind, placebo-controlled, linear dose, crossover study to evaluate the efficacy and safety of a green coffee bean extract in 16 overweight subjects. This is the language scientists use to tell you that neither the subjects nor the researchers knew who was getting the extra cholorgenic acid in their beverage. The study was also designed to rule out the placebo effect, and each test group was assessed using each modality: a high dose of cholorgenic acid (1050 mg) , a low dose (700 mg), and the placebo. Dietary intake was assessed, and seems to remain rather consistent through each phase of the study—or at least the pooled data from each phase looked the same. You can’t really tell from the graph.