Green Coffee Bean Extract: Does It Aid In Weight Loss?

In August, I wrote a blog about fad diets that lists several common fad diet claims illustrated on the Academy’s website.  After recently hearing about green coffee bean extract, which is being used as a weight loss supplement, I had to do a little more research on it.  In September 2012, Dr. Oz first described the weight loss benefits of taking a green coffee bean extract and the episode aired again toward the end of December 2012.

Journeying to Dr. Oz’s website, I watched the episode in a series of five parts and also found a Fact Sheet: Green Coffee Bean article which describes what ‘green coffee’ is.  Green coffee beans are simply traditional coffee beans that have yet to be roasted.  A component of green coffee, called chlorogenic acid, has “specifically been shown to inhibit an enzyme, glucose-6-phosphatase, that promotes the formation of glucose in the liver.”  Unfortunately, traditionally brewed coffee is not a significant source of chlorogenic acid because of the roasting process.  This is the reason behind taking the green coffee bean extract; it has more chlorogenic acid which may lead to weight loss.

In the beginning of the episode, Dr. Oz mentions he was not paid to say this supplement is a miracle, but he does claim it helps burn fat faster.  He briefly refers to a small study that was conducted  and sparked the green coffee bean extract craze without describing the mechanism behind weight loss.  Two guests of the show are weight loss specialist, Caroline Apovian, MD, and nutritionist, Kristin Kirkpatrick, MS, RD, LD who helped Dr. Oz conduct a TV study of 100 women in his audience.  Kristin Kirkpatrick says she recommended all participants to keep a food log without changing their diet.  One hundred women between the ages of 35 and 49 years with a body mass index (BMI) between 25-45 kg/m2 took part in the TV study.  These women had no history of diabetes, heart attack, or stroke, and were not pregnant or breast feeding.  About half of the participants received the green coffee bean extract, while the others received a placebo that everyone took three times per day and 30 minutes before each meal for two weeks.

The results of the TV study found an overall weight loss of 123 pounds in two weeks.  Of the women who received the placebo, 41.5 pounds were shed, while the group who took the supplement lost 81.5 pounds total.  The average weight loss was about 1.2 pounds over a period of two weeks.  Dr. Oz goes on to interview a few women in the audience about their experience and one woman who was taking the placebo stated she didn’t lose weight, but did notice she wasn’t eating as much.  This could be attributed to “mind over matter” since there was a chance she was taking the supplement or to the food log she kept.  Another woman who discovered she was given the extract lost 4 pounds in two weeks.

The episode ended with tips about what to look for if considering this weight loss supplement such as, look for Svetol or GCA (green coffee antioxidant) in the ingredients list; at least 45% chlorogenic acid; and the dose should be 400 mg three times daily and 30 minutes before meals.  These pills don’t come cheap either; a 30 day supply can run about $30.00.  Dr. Oz goes on to say that there are no harmful side effects, but because we “don’t know enough about it” the supplement is not appropriate for anyone younger than 18 years, pregnant women, or breast feeding women.

The episode and reading the fact sheet sparked many questions, like what are the side effects, is there a safe length of time to take the supplement, are there other studies, and what is the weight loss mechanism, among many others.  Luckily, there was a link to the original study so I could gather more information.  As mentioned above, this was a small study of 16 participants taking place in India and was a 22-week crossover study where each participant received a high-dose of green coffee extract, a low-dose of green coffee extract, and a placebo.  Subjects remained on a treatment plan for 6 weeks which was followed by a 2-week relax period before starting the next treatment.  Everyone was also counseled by a nutritionist on diet and exercise at every visit.

The results showed that participants lost weight on both the high-dose and low-dose treatment plans.  There was greater average weight loss with the high-dose treatment (about 4.5 pounds) than the low-dose treatment (about 3.4 pounds).  The very first sentence in the discussion section of the journal article states, “The mechanism(s) of the significant effect of GCA on weight loss, BMI, percent body fat, and heart rate are unknown.”  It goes on to describe chlorogenic acid in animal studies as inhibiting sugar absorption from carbohydrates while also having moderate effects on fat metabolism (both retarding the absorption of fat and activating fat metabolism in the liver).  These claims of altering metabolism of macronutrients may cause fewer calories to be absorbed; therefore, leading to weight loss.

Overall, every participant, no matter the study, was overweight or obese and took a form of the supplement for at least two weeks.  Weight loss among participants is not consistent and varies from no weight loss to less than 5 pounds over a 2-week period or 6-week period.  Subjects were supposed to continue their normal diet.  In my professional opinion, the green coffee bean extract, or chlorogenic acid, or GCA doesn’t seem to be worth the cost.  If I had the choice between paying $30.00 per month to be lucky to lose 4 pounds with the supplement or spending the same amount on a gym membership to see better results…I’d pick the gym.

In the new year, I will strive to motivate family, friends, and others to eat a balanced diet and to be active.  I hope people choose to lose weight in a healthy manner by eating more fruits and vegetables while increasing the amount of physical activity they get weekly.  In a few months, the Academy of Nutrition and Dietetics will be celebrating National Nutrition Month with a theme of “Eat Right, Your Way, Every Day.”  I conclude with advocating eating healthy foods every day and eating foods that you enjoy and have a very happy new year!