When it comes to nutritional supplements and weight loss, it seems that no one is more effective at promoting them than Dr. Oz.
By advocating a wide variety of these supplements on his popular daytime TV show, he’s effectively paved the way for countless manufacturers to enter the market and to make a whole lot of money in the process.
Just like with Garcinia Cambogia and Raspberry Ketone, green coffee bean extract first appeared on the Dr. Oz show in 2012, where he claimed that “this miracle pill can burn fat fast, for anyone who wants to lose weight.”
After this occurred, hundreds of manufacturers jumped on the bandwagon and flooded the market with their green coffee bean extracts, each claiming to be better than the next.
Unfortunately, when something like this occurs, it can quickly become difficult to discern fact from fiction, and marketing hype from real-world results.
Because of this, we here at HighYa decided to really dig into this new “miracle” supplement and to find out what it’s all about.
What exactly is green coffee bean extract? What are its claimed benefits? Is it really effective? And what do the experts have to say about it? Let’s find out.
What Are the Benefits of Green Coffee Bean Extract?
Unprocessed (e.g. “green”) coffee beans contain high levels of chlorogenic acid, an antioxidant that may delay glucose from entering your bloodstream, and may also increase metabolic processes.
When fat from the food you eat is prevented from immediately entering your bloodstream after digestion, your body has a greater opportunity to “burn” existing fat.
As a result, the amount of unused energy, or excess fat, is greatly reduced, which purportedly helps you to lose weight. But is there any truth to this?
Can Green Coffee Bean Extract Really Help You Lose Weight?
As we mentioned above, Dr. Oz is fond of promoting the benefits of many of the latest and greatest supplements. In fact, he’s almost solely responsible for the huge increase in popularity for green coffee bean extract (GCA).
But is there any solid evidence behind these claims?
Dr. Oz originally referenced this study in his May 2012 broadcast, which involved a very small pool of just 16 participants, each of which received either a high dose of GCA, a low dose or a placebo. Participants were then given one of these three doses over the course of six weeks, with two-week breaks in between cycles.
Once everything was said and done, subjects were claimed to have lost an average of 17 pounds, which was greater than the amount they lost when they weren’t taking the supplement. Sounds pretty goods, right? Perhaps, but consider the following:
Because of the informal nature of the study, and because all three dosage levels were given to all 16 participants at one point or another, we don’t know how much weight loss can be attributed to GCA, and how much is simply due to monitoring diet.
The study was completed in India, and the results were then emailed to Joe Vinson, a researcher from the University of Scranton, who formally wrote the study we linked to above. On top of this, according to this Forbes article, “Vinson was paid by the makers of GCA to write the study.
Worse yet, the paper states that “The authors report no conflicts of interest in this work.” When asked about this by The Globe and Mail, “Vinson said that he doesn’t gain financially if the company sells a lot of product and that the journal didn’t require him to disclose the relationship.”
Because of this, Dr. Oz and his claims about green coffee bean extract were placed under quite a bit of public scrutiny. So, several months later, he aired a follow-up episode, where he enlisted the help of 100 women between the ages of 35 and 49, who had a BMI between 25 and 45; no history of diabetes, heart attack, or stroke; were not currently pregnant or breastfeeding; and who adhered to similar diets.
Over the course of two weeks, each participant ate as they normally would, kept a food log, and took the pills they were given (either green coffee bean extract or a placebo—none knew which they were receiving). So what was the result of the experience?
Here is the transcript from Dr. Oz’s website:
“In two weeks, the group of women who took the green coffee bean extract lost, on average, two pounds. However, the group of women who took the placebo lost an average of one pound – possibly because they were more aware of their diet for that two weeks because of the required food journal.”
At this point, you may be saying to yourself, “Ok, so the study Dr. Oz originally cited, as well as the one he hosted on his show, were badly flawed. But there have to be other studies out there that prove the efficacy of Green Coffee Bean Extract, right?” Let’s see.
What Do Clinical Studies Have to Say About Green Coffee Bean Extract?
Taking a look at the National Institutes of Health PubMed, a search for “chlorogenic acid” returned nearly 2,600 results, which explore everything from its antioxidant properties to its evolution, but very few that reference its weight loss properties. In fact, out of these 2,600 results, we could find only three that associated chlorogenic acid with weight loss:
1. This one, which was conducted using Svetol, a trademarked, natural green coffee bean extract. All we have to reference is a short extract, which ends by stating, “The results of this study provide a further mechanism by which to explain the long-term health benefits of CGAs and Svetol®.” However, none of these mechanisms are cited.
2. This one, which appears to closely mirror the study originally referenced in the first Dr. Oz green coffee bean extract show.
3. And this one, which claims that the ingestion of caffeinated and decaffeinated coffee (not green coffee bean extract), makes it “possible that caffeine and other constituents of coffee, such as chlorogenic acid and quinides, are involved in causing weight loss.” In other words, there was no conclusive evidence that chlorogenic acid had any effect on weight loss.
However, if you search for “green coffee bean extract,” you’ll receive just over 20 results, only two of which reference weight loss:
This recent study performed on mice, which were fed a high-fat diet over the course of 12 weeks. During this time, they were given 0.5% green coffee bean extract. The researchers ultimately found that “the mice fed a HFD and HFD+GCE displayed symptoms of the metabolic syndrome compared to their normal fed counterparts.”
This one, which showed that mice who were given “0.5% and 1% GCBE reduced visceral fat content and body weight.”
Taken together, what does all of this mean?
In short, it means that there is little evidence to show that green coffee bean extract, or its active ingredient chlorogenic acid, have any effective on weight loss.
And for those that may point in this general direction, the only ones that remotely stand up to scrutiny were performed on mice, not on humans.
At best, as WebMD puts it, the claims made by green coffee bean extract manufacturers are “possibly ineffective.”
What Should I Look for in a Green Coffee Bean Supplement?
As mentioned above, there is little scientific evidence showing green coffee bean extract is effective, to begin with, and even less evidence outlining dosage and possible side effects.
In fact, nutritional supplements of any stripe are subject to very little oversight by the FDA, so quality standards prior to reaching the market are extremely varied.
With this in mind, you always want to make sure a supplement manufacturer:
- has a positive online reputation,
- that their supplements are third-party tested,
- and preferably, that the company was in business prior to Dr. Oz’s broadcast in May 2012.
Be sure to read through our Supplement Guide for many more insights.
From a dosage perspective, Svetol is typically administered in 80-200mg daily doses, while we found other manufacturers offering as much as 1600mg daily doses. Again, as with many other aspects of green coffee bean extract, there is little consensus on how much you should take.
Finally, it’s difficult to conclusively say whether or not there are any serious side effects related to green coffee bean extract. As of now, though, it is considered generally safe. However, green coffee bean extract does contain caffeine, so caffeine-sensitive individuals should be wary of taking it.