Since 1989, when I started in the fitness business, I’ve seen dozens of diet supplements burst onto the scene, sell into the multi-millions, only to drop off the map and end up buried in the graveyard of fat loss products (that we now know never worked in the first place). The shelf life is usually a year or two – three if they’re lucky – before the FTC sues or the product dies a natural death as the novelty wears off. They’re promptly replaced by “the next big thing” … an African cactus, a berry from the Amazonian rain forests, an ancient Asian tea, an herb from the Himalayas… sound familiar? There’s always an exotic story that hooks people again, isn’t there?
green-coffee-beanWatching this relentless cycle repeat itself always irked me. Years ago, every time one of these “miracle pills” hit the mainstream I used to jump on my soapbox and warn my readers, “Please don’t waste your money!” After seeing even the smartest people continue buying the hype, or telling me, “As long as it’s safe, what does it hurt to try?” I became disenchanted, so I didn’t bother much anymore. But I have to admit, the case of green coffee bean got me riled up again. This product just won’t die. It’s like a turd that won’t flush.
After witnessing green coffee bean and other “as seen on TV” products reach new highs in sales and visibility with new lows in integrity, I knew it was time to get back on my blog and start preaching again (can I get an amen?) This will be more than a good rant. I’m going to reveal what the science really says and I’ll share some advice you can generalize to all weight loss products to help you save time, money, frustration and maybe even your health. First, some background…
What is green coffee bean extract?
When you think of active ingredients in coffee, the first thing that usually comes to mind is caffeine. But caffeine isn’t the only biologically active substance in coffee – it also contains phenolic compounds (polyphenols) including chlorogenic acids (CGA). CGA is found in many fruits and vegetables, but green coffee bean contains more than any other plant source. CGA can also be found in roasted coffee beans, but some is lost in the roasting process. This explains the interest in the unroasted bean – the green coffee bean.
Early studies on mice revealed that CGA might have health benefits. There was particular interest in coffee polyphenols for their potential role in managing blood sugar and reducing type-2 diabetes risk. It should come as no surprise, given the $61 billion market, that enterprising researchers also wondered if the benefits included weight loss.   Green coffee extract doesn’t appear to be a thermogenic or appetite suppressant, but one leading theory is that CGA might decrease the rate of glucose absorption in the small intestine by interfering with starch breakdown, or affect glucose metabolism in a way that leads to less fat deposition and easier withdrawal of fat from adipose tissue.
The problem is, rodent studies don’t translate well to humans, so unless you have a chubby hamster and you want to slim down your furry pet, this kind of data isn’t very relevant. There was enough interest in green coffee extract however, that a few human studies were eventually funded by the green coffee bean manufacturers. That unfortunately, is part of the problem. When the salesmen say there’s human research supporting their product, they’re not lying. But what they’re not not telling you is that all the research is industry-sponsored. In this case, it’s also full of flaws.
Problems with the green coffee bean research
The first human study was done in 2006 and published in the journal, Phytotherapie. Fifty volunteers were assigned to either a treatment group, which received one 200 mg capsule of Svetol, a green coffee bean product, or a control group, which received a placebo. The control group lost 0.54 pounds a week, while the green coffee group lost 1.27 pounds a week. These findings look significant, but the research was poorly designed.
The results were based on subjects who finished the trial, but no information was given about who or how many dropped out. How the study was blinded was not made clear, and the study duration was fairly short. The study was also funded by the manufacturer of the product, and yet no conflict of interest was disclosed. Funding source does not prove bias in a study, but it sure makes me put a big asterisk next to it.
In 2007, another study was published in the Journal of International Medical Research. Six males and six females, all slightly to moderately overweight, participated in the 12-week study. The test group drank 2200 mg of “Coffee Slender,” a coffee beverage with a high concentration of GCA (200 mg of green coffee extract with 45-50% CGA’s, yielding 90 to 100 mg). The control group drank regular instant coffee. The CGA-enhanced coffee group lost 11.9 pounds, while the control group lost 3.7 pounds. These results were called clinically significant. However, this study had almost all of the same flaws as the earlier study, and was also industry-funded.
In 2012, a third human study was conducted in India and written up in the journal Diabetes, Metabolic Syndrome and Obesity. Subjects received larger doses than previous trials – either 1050 mg or 700 mg with a CGA content of 45.9% – and they averaged 17 pounds in weight loss. That’s with no claimed change to diet or exercise patterns (which, by the way, is one of the biggest red flags in an advertisement for a weight loss scam, according to the FTC).
This study too, was funded by a company that makes green coffee bean extract (Applied Food Sciences Inc), and had many design flaws. There were only 16 subjects, with only 4 to 6 people in each group. Randomization method was not described, and one group was given two doses a day and the other groups three, which does not blind the researchers or the participants. The results were strange. All the subjects lost the majority of their weight in the first 6 weeks, and subjects also continued to lose weight during the washout periods.  In one arm of the study, the placebo group lost almost as much weight as the high dose group. How do we know the weight loss wasn’t just random chance or unreported changes to food intake or activity levels?
At the University of Exeter in the United Kingdom, researchers did a meta analysis of all the studies to date and they had the same doubts about the study designs. “The results from these trials are promising,” they concluded, “But the studies are all of poor methodological quality. More rigorous trials are needed to assess the usefulness of GCE as a weight loss tool.”
The Oz Effect
What about the “Dr. Oz Study” you may have heard about? Actually, Oz never conducted or published a formal study, he merely gave some anecdotes on his TV show. In one episode, which aired in 2012, Oz said that he gave the supplements to two viewers and one dropped 2 pounds in 5 days and the other lost 6 pounds in 5 days.  The buzz created from that first show resulted in an explosion of green coffee ads online, and Oz found his face and endorsement (without his permission) on hundreds of websites hawking green coffee bean (reminiscent of what happened to Oprah with Acai berry).
Oz caught a lot of flack for that, not to mention the trouble his legal team must have gone through trying to take down all those unauthorized ads. What did he do? Surprisingly, he did another show on green coffee bean a few months later! He said he was doing his own “study,” but all he did was round up 100 female members of his studio audience, who took either green coffee bean extract or placebo for two weeks.  He said the women who took the green coffee lost, on average, two pounds and the women who took the placebo only lost one pound. From this made for TV experiment he concluded,  “Green coffee bean worked for us.” That’s not exactly the gold standard of scientific research, is it?
Another problem is that there’s no consensus on dose or delivery method.  The first two studies used 200 mg of green coffee bean extract with 45 to 50% CGA. One of those studies delivered it in a coffee beverage. The third study tested higher doses at 1050 mg or 700 mg of green coffee bean extract standardized to 45.9% CGA in capsules.
Here’s another interesting factoid I uncovered in the food science journals:  Contrary to what some supplement ads say, roasted coffee beans do contain CGA. Coffees with long roasting times may lose much of their CGA content, but a 200 ml cup of roasted ground coffee can supply anywhere from 20 to 675 mg of coffee polyphenols. That means the typical coffee drinker may already be getting 0.5 to 1.0 grams per day.
This raises some questions. Why would coffee drinkers need the supplement at all? Why doesn’t coffee help us lose weight?  If you take a supplement on top of drinking coffee, could too much caffeine or polyphenol intake be unhealthy? Why hasn’t any research compared coffee drinkers versus non coffee drinkers? Can we assume that if there’s any fat loss benefit for coffee or coffee extracts, it’s not much, it’s gained mostly at the beginning of the usage period (doesn’t help long term) and it doesn’t work for habitual drinkers?
Quality control and safety
Many supplements don’t even contain what the label claims.  Lack of quality control or cutting corners to save money, either way, it’s a problem. Products should be formulated to match doses used in the research. If 200 mg of extract standardized at 45% was the minimum effective dose in the research and a supplement includes a serving size of only 50 mg, you’re getting short-changed. tested 8 popular green coffee bean extract products, and they discovered that half of them did not meet label claims for total extract or CGA. One of them contained no active ingredient whatsoever and this was a brand commonly found in drugstores like CVS and Walgreens.
Tainted products are another problem, as discussed in the Federal Trade Commission’s guide,”Weighing the Claims in Diet Ads”:
“In the last few years, the FDA has discovered hundreds of dietary supplements containing drugs or other chemicals, often in products for weight loss and bodybuilding. These extras generally aren’t listed on the label – and might even be sold with false and misleading claims like “100% natural” and “safe.” They could cause serious side effects or interact in dangerous ways with medicines or other supplements you’re taking.”
(as a sidebar, I saw this disclosure posted on a tub of protein powder at the health food store the other day: “This product manufactured in a facility free of banned substances.”  That’s what it has come to).
It shocks me how many people will pop over-the-counter pills blindly without safety even crossing their minds. It’s a common belief that if something makes it onto a health food store shelf or is natural, it must be safe, but in fact, this is part of the naturalistic fallacy. Plants and other naturally-occurring substances can be poisonous. They can also be beneficial or neutral in low doses but harmful in a high dose. Individual tolerance may vary as well, as some people have allergies, take meds or have medical conditions.
Terry Graham, PhD, a coffee expert and physiologist at the University of Guelph explains how green coffee extract may not be entirely risk-free: “They (chlorogenic acids) are definitely exciting compounds, but their effects are still not well known. If chlorogenic acids do in fact block carbohydrate absorption, that may not necessarily be a healthy outcome. Supplements that meddle with digestion can cause malnutrition, diarrhea, and other health problems.”
The bottom line
The evidence for green coffee bean extract is pitifully weak. It’s another over-hyped, flavor-of-the month product in the “miracle pill” sales cycle that’s been repeating itself for decades. The supplement company fat cats capitalize on media buzz and oversell the limited early research.  Instead of waiting to see if effectiveness and safety are confirmed with ongoing quality studies combined with satisfied customers, they make as much money as they can as early and fast as they can.
If the product doesn’t pan out, or we discover dangerous side effects, it’s no sweat off the company’s back to say, “Oh well… oops, sorry.” They don’t care; they already skimmed off the cream and cashed out.  In fact, the lag between when a potential anti-obesity product is first discovered and when there’s a preponderance of evidence showing whether it works or not, is just enough time to make millions. Supplement companies not only know this – that’s their business model: Strike while the iron of hype is hot, and if you get lucky with media attention, mine it even deeper, then move on to the next fad.
If a product does pan out, everyone is happy, but don’t hold your breath – the track record is dismal. The rare ones that do work, hardly work at all, it’s almost impossible to tell how much it’s helping compared to the dieting and exercising you’re doing  and the advertisements are notorious for exaggerating claims and using fake testimonials. Ordering online from a company you don’t know you can trust can also get you caught up in one of those ubiquitous credit card scams.
The bottom line is that there’s very little evidence for any weight loss supplements. The way I see it, the entire fat loss supplement business is just short of one giant scam. Year after year, the industry has produced dud after dud, made empty promise after empty promise. My advice: Say no to weight loss supplements completely and put your focus on good food and hard training, where it really counts.

About Tom Venuto

tom-venuto-author - CopyTom Venuto is a natural bodybuilder, fat loss coach, fitness writer and author of Burn The Fat, Feed The Muscle. Tom’s articles are published on hundreds of websites worldwide and he has been featured in Muscle and Fitness, Men’s Fitness, Oprah magazine, The New York Daily News, The New York Times and the Wall Street Journal. He has appeared on dozens of podcasts and radio shows including Sirius XM, ESPN-1250 and WCBS. Tom is also the founder and CEO of the premier fat loss support community, the Burn The Fat Inner Circle

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