True or False: Mycotoxins in Coffee Are a Serious Threat to Our Health and the Only Way to Avoid Them is Abstinence

As we are about to see coffee is by far not the worst aflotoxin offender in the human diet. Still, that does not mean that the coffee related exposure to this form of mold that can befall all sorts of grains, nuts and seeds is harmless.

You will probably remember that I casually touched on the possibility of being exposed to aflotoxins and more importantly ochratoxins as a result of the consumption of mold-infected coffee in previous coffee articles. When the issue of the « coffee ➲ aflotoxin / ochratoxin exposure ➲ serious health » triage resurfaced in a brief facebook conversation, recently, I realized that I was not 100% sure if these mycotoxins that are produced by Aspergillus flavus, Aspergillus ochraceus, Aspergillus niger, and Aspergillus carbonarius do or don't pose a serious health risk.

Well, you know how much I hate unanswered questions, so I kept digging until I'd found what I consider to be a half-way satisfying answer to this life-or-death question ;-)

You can learn more about coffee at the SuppVersity

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Coffee + Cacao for Breast Cancer Prevention

"Decaf" Won't Help With Weight, ... Ahh, Fat Loss

"The amount of aflotoxin in the average cup of coffee is a serious threat to our health!"

In 90% of the cases the above statement is FALSE! Despite the fact that it is difficult to tell how much mycotoxins you've been flushing down with your morning coffee today, the exact amount of the more common aflotoxins and their similarly kidney-toxic, pro-carcinogenic and coffee-loving cousins, the ochratoxin, in the average cup of (roasted) coffee is probably way too low to be worried about.

Figure 1: Mycotoxin exposure from coffee; calculated based on data from Europe (Vd Stegen. 1997)

Based on the studies I have reviewed for this article, it appears almost certain to say that the relatively low amount of coffee beans per cup (4-8g) reduces your average mycotoxin exposure from 1-4 cups of coffee per day to levels that are almost certainly within one of the various (multi-)national reference ranges (Van Egmond. 2007):

• Europe: 5µg/kg
• Africa: 10µg/kg

• North America: 20µg/kg

• Asia: 15µg/kg
• Latin America: 20µg/kg

Using a selection of commercially available regular and soluble coffee brands, van der Stegen et al. have actually calculated the average daily mycotoxin intake of Europeans with an average coffee consumption of 1-4  to be in the nanogram range - 19ng and 10ng, specifically, for regular and instant coffee drinkers, respectively.

Please remember: We don't know if / what happens or doesn't happen if you stay within or break the arbitrary intake limits. If you take a look at the available evidence from rodent studies, the results Epstein et al. presented in their 1969 paper (see Table 1) later in this article, would suggest that a sensible intake limit would have to be below the 1µg range if we assume a similar toxicity for the average mycotoxin mixture as for the aflotoxin B Epstein et al. used. This assumption is obviously not realistic, but it should remind you of the arbitrariness of the "intake limits".

Just to make sure, we understand each other, here: That's 1000x less than you'd get from only 20g of some of the Brazilian peanuts Freitas and Brigido analyzed in a 1998 study for their mean and maximal mycotoxin content. With 1099µg/kg the worst offenders in this study would easily have you breach the already lax American (North & Latin America) max. tolerable intake limit of 20µg/kg per day - and that despite the fact that this limit is more than 1000x higher than the amount of mycotoxins you'll have in your average cup of coffee.

Green vs. roasted coffee: Do we have to chose between anti-oxidants and mycotoxins?

It goes without saying that the mere fact that the dangers of being exposed to high amounts of mycotoxins from adequately processed and stored coffee appears negligible, does not warrant ignoring the problem completely. The effects of processing and storage are and will thus always be an important issue.

Given the fact that humid and cool (but not cold) is what mold needs to thrive, you will probably already have suspected that the hot and arid environment of a coffee roastery is not exactly the favorite growth environment for the Aspergillus family.

Figure 2: Ochratoxin content (µg/kg) in green, roasted & soluble coffee, left; total antioxidant activity in TROLOX essay of green (=unroasted), lightly, medium and dark roast coffee (Blanc. 1998; del Castillo. 2002)

A lower mycotoxin content is yet not the only beneficial effect of roasting. Contrary to what 99% of the people will tell you, when you ask them, the roasting process increases not decreases the total antioxidant capacity of coffee (TAC).

What does the latest review say about regular coffee consumption and cancer? "The epidemiological evidence consis-tently indicates that coffee protects against liver cancer, and also point toward protective effects for risk of colorectal cancers (with relative risks of 0.50 (95% CI: 0.42–0.59) and 0.83 (95% CI: 0.75–0.92), respectively, in the most recent meta-analyses)" (Bøhn. 2013). The evidence for protective effects against breast and prostate cancer on the other hand is inconclusive - irrespective of the established chemo-preventive effects of coffee phytochemicals Bøhn et al. list in their soon to be published paper in Molecular Nutrition & Food Research early in 2014.

Due to the formation of a whole host of new antioxidant molecules during the roasting process, light or mildly roasted coffee beans have a higher total antioxidant capacity than green ones - irrespective of the reduced chlorogenic acid content, for which the green beans are currently (over-)hyped. If you look at the data in Figure 2 you will see that even the heavily roasted, tar-black coffee beans still have a minimally higher anti-oxidant activity than the "natural" green coffee beans (del Castillo. 2002) - an observation that has been made both in the Petri dish, as well as ex vivo rodent studies (Daglia. 2002).

You've been drinking tons green coffee, lately?

Don't worry! Your past green coffee consumption probably isn't a real problem either. It does after all look as if those beans were yet another example for the infamous "nature kows best" principle. I mean, can it really be "coincidence" that the beans come with "anti-mycotoxin agents" in form of cafestol and kahweol. These coffee-specific diterpenes have been shown to ameliorate the aflotoxin B induced genotoxicity (Cavin. 1998) and the subsequent pro-carcinogenic effects (Cavin. 2001) and can be expected to exert protective effects against ochratoxin toxicity, as well.

In view of the fact that similar evidence exists for chlorogenic acids (CGA), dodecyl chlorogenates (DCGA) and a high(er) coffee consumption, in general (Suárez‐Quiroz. 2013; Ferk. 2013), it is actually not surprising that studies like Shank et al. (1972)  or Bulatoa-Jaym et al. (1982) found links between aflotoxin contaminated corn, grains, potato, peanuts & co., but could not identify an increased risk in liver cancer for coffee aficionados. Consequently, it's (imho) relatively unlikely that your health has already taken a beating - irrespective of the amount of the number of cups of green coffee you've been consuming over the past weeks.

Coffee is not the worst mycotoxin offender in the human diet: In a case-control dietary study of primary liver cancer in humans Bulatoa-Jaym et al. found that 51.2% of their subjects daily aflotoxin exposure came from cassava, 20.3% from corn, 6.8% frompeanuts and 5.8% from sweet potato (Bulatao-Jaim. 1982). On the other hand, many scientists argue that the ochratoxin content of coffee is the real danger, anyway (Bayman. 2006)

I would still like to remind you that even the sum of the previous remarks must not be misunderstood as an incentive to willy nilly forget all previously harbored concerns about "moldy coffee beans"... and I say this in spite of the existing epidemiological evidence that a high coffee consumption decreases the risk of developing and dying from liver cancer (Kurozawa. 2005; El–Serag. 2007). The liver is after all not the only organ that may be affected by the pro-carcinogenic toxins. The kidneys are at least as susceptible to the toxic assault from the mycotoxin filtrate that passes through them.

The liver is not the only organ that's taking a beating

It may thus be hypothetical, but not impossible that a 2x / 2.6x increased risk to develop renal cell carcinoma Mimi et al. report in a 1986 paper on the associations between coffee consumption and kidney cancer may at least be partially related to the higher mycotoxin exposure in those 61 study participants who consumed 1-4 cups of coffee per day (Mimi. 1986).

That mycotoxins can promote the development of kindey cancer had been demonstrated 17 years before the publication of Mimi's paper by Epstein, Bartus & Farber (1969) whose Wistar rats developed renal epithelial neoplasms after being exposed to food-borne aflatoxin B1.

Table 1: Incidence of renal epithelial and malignant hepatic tumors in male Wistar rats ingesting aflatoxin B1 for 147 days; the indces a, b, c provide irrelevant (in this context) extra information (Epstein. 1969)

In that, it's quite remarkable that even the lowest aflotoxin dosage the researchers used in their study (0.25µg/kg chow; HED  ~1.2ng/kg body weight, ; see Table 1) lead to significant rates of cancerous growth in both kidney (28%, if we count both developing and full-blown renal neoplasms) and liver  within the 21 week study period.

There is just one no-go: Storing unroasted beans for years in your humid basement

In view of the large regional difference in aflotoxin infection rates, the different susceptibility of the various coffee cultivars and the influences of weather, storage conditions, blending, processing, and all the other factors that increase or decrease the amount of mold and mycotoxins on coffee (see Figure 3), I would still be hesitant to exclude the possibility that stocking up on highly aflotoxin contaminated unroasted coffee you possibly even stock in a very humid basement of yours to consume the coffee over the course of months if not years could have negative effects on the health of your organs, in general, and the function of your kidney and liver, in particular.

Figure 3: Percent infection of coffee cherries and beans byAspergillusspecies potentially capable of producing ochratoxin A in four Brazilian coffee growing regions from the 1999 and 2000 harvests (Taniwaki. 2003)

I mean, look at the data in Figure 3. It's probably no coincidence that the otherwise virtually uninfected beans of coffee from the 1999 and 2000 harvests in the Cerrado Miniero exhibits a 4% infection rate after being stored intermediately before it is either roasted, shredded or both or simply forwarded "raw" to the mailbox of an "unroasted coffee enthusiast". Similar effects can be expected when the huge coffee manufacturers mix harvests from various regions. If only one is infected, all it takes to have Aspergillus flavus literally "all over the place" is enough time in one of the huge storage silos or the hold of one of the container ships that transport coffee from the "New" back into the "Old World".

Figure 4: The amino acid make up of coffee changes upon roasting (data from Cirilo. 2003).

Life kills, anyway! Let's be honest. In the end, living is a pretty deadly undertaking, anyway. Against that background the uncertainty with respect to the tolerable intake of mycotoxins should not bother you so much to ignore the existing evidence of the beneficial effects of regular coffee consumption (see "Coffee - The Good, the Bad & The Interesting" | read more).

One thing you may keep in mind, though, is that this evidence is based on data from average coffee drinkers, people who drink coffee that's made of roasted beans. Beans that are virtually mycotoxin-free (see Figure 2, left) and have a higher, not lower antioxidant capacity than green coffee beans.

What roasted beans lack, though, are chlorogenic acid and trace amounts of amino acids (see Figure 4), including serotonin. If you are looking for one of these molecules specifically, you are yet probably better of with a hopefully aflotoxin and mycotoxin free green coffee extract and a bottle of pills with the serotonin precursor 5-HTP, anyways.

References:

• Bayman, P., & Baker, J. L. (2006). Ochratoxins: a global perspective. Mycopathologia, 162(3), 215-223. 
• Blanc, M., Pittet, A., Muñoz-Box, R., & Viani, R. (1998). Behavior of ochratoxin A during green coffee roasting and soluble coffee manufacture. Journal of agricultural and food chemistry, 46(2), 673-675.
• Bøhn et al. (2013) Coffee and cancer risk, epidemiological evidence, and molecular mechanisms. Molecular Nutrition & Food Research [early view article]
• Bulatoa-Jaym J, et al. (1982). A Case-Control Dietary Study of Primary Liver Cancer Risk from Aflatoxin Exposure*. International journal of epidemiology, 11(2), 112-119.
• Cavin, C., Holzhäuser, D., Constable, A., Huggett, A. C., & Schilter, B. (1998). The coffee-specific diterpenes cafestol and kahweol protect against aflatoxin B1-induced genotoxicity through a dual mechanism. Carcinogenesis, 19(8), 1369-1375.
• Cavin, C., Mace, K., Offord, E. A., & Schilter, B. (2001). Protective effects of coffee diterpenes against aflatoxin B< sub> 1</sub>-induced genotoxicity: mechanisms in rat and human cells. Food and Chemical toxicology, 39(6), 549-556.
• del Castillo, M. D., Ames, J. M., & Gordon, M. H. (2002). Effect of roasting on the antioxidant activity of coffee brews. Journal of Agricultural and Food Chemistry, 50(13), 3698-3703. 
• Cirilo, M. P., Coelho, A. F. S., Araújo, C. M., Gonçalves, F. R., Nogueira, F. D., & Glória, M. B. A. (2003). Profile and levels of bioactive amines in green and roasted coffee. Food Chemistry, 82(3), 397-402.
• Daglia, M., Papetti, A., Gregotti, C., Bertè, F., & Gazzani, G. (2000). In vitro antioxidant and ex vivo protective activities of green and roasted coffee. Journal of Agricultural and Food Chemistry, 48(5), 1449-1454.
• Epstein, S. M., Bartus, B., & Farber, E. (1969). Renal epithelial neoplasms induced in male Wistar rats by oral aflatoxin B1. Cancer Research, 29(5), 1045-1050.
• El–Serag, H. B., & Rudolph, K. L. (2007). Hepatocellular carcinoma: epidemiology and molecular carcinogenesis. Gastroenterology, 132(7), 2557-2576. 
• Ferk, F., Huber, W. W., Grasl‐Kraupp, B., Speer, K., Buchmann, S., Bohacek, R., ... & Knasmüller, S. (2013). Protective effects of coffee against induction of DNA damage and pre‐neoplastic foci by aflatoxin B1. Molecular nutrition & food research. 
• Freitas, V. P., & Brigido, B. M. (1998). Occurrence of aflatoxins B1, B2, G1, and G2 in peanuts and their products marketed in the region of Campinas, Brazil in 1995 and 1996. Food Additives & Contaminants, 15(7), 807-811.
• Kurozawa, Y., Ogimoto, I., Shibata, A., Nose, T., Yoshimura, T., Suzuki, H., ... & Tamakoshi, A. (2005). Coffee and risk of death from hepatocellular carcinoma in a large cohort study in Japan. British journal of cancer, 93(5), 607-610. 
• Mimi, C. Y., Mack, T. M., Hanisch, R., Cicioni, C., & Henderson, B. E. (1986). Cigarette smoking, obesity, diuretic use, and coffee consumption as risk factors for renal cell carcinoma. Journal of the National Cancer Institute, 77(2), 351-356.
• Shank, R. C., Wogan, G. N., & Gibson, J. B. (1972). Dietary aflatoxins and human liver cancer. I. Toxigenic moulds in foods and foodstuffs of tropical South-East Asia. Food and Cosmetics Toxicology, 10(1), 51-60.
• Taniwaki, M. H., Pitt, J. I., Teixeira, A. A., & Iamanaka, B. T. (2003). The source of ochratoxin A in Brazilian coffee and its formation in relation to processing methods. International Journal of Food Microbiology, 82(2), 173-179. 
• Van Egmond, H. P., Schothorst, R. C., & Jonker, M. A. (2007). Regulations relating to mycotoxins in food. Analytical and bioanalytical chemistry, 389(1), 147-157. 
• Vd Stegen, G., Jörissen, U., Pittet, A., Saccon, M., Steiner, W., Vincenzi, M., ... & Schlatter, C. (1997). Screening of European coffee final products for occurrence of ochratoxin A (OTA). Food Additives & Contaminants, 14(3), 211-216. 
• Yamato, T., Yamasaki, S., Misumi, Y., Kino, M., Obata, T., & Aomine, M. (2002). Modulation of the stress response by coffee: an in vivo microdialysis study of hippocampal serotonin and dopamine levels in rat. Neuroscience letters, 332(2), 87-90.

Caffeine & Cholorogenic Acid - Anti-Obesity Agents from Your Coffee Mug? Human Study Reveals Cortisol Lowering Effects, Mouse Study Confirms Anti-Obesity Effects

Ever since the Vinson study showed that green coffee bean extracts can help overweight women lose weight, green coffee is sexier than roasted one.

Only weeks after Vinson et al. were able to show that "Green Coffee Bean Extract Helps Pre-Obese Men and Women Shed 16lbs in 22 Weeks" (read more), green coffee bean supplements began to swamp the market - a great financial success for the supplement producers, and that despite the fact that follow-up studies that would confirm the amazing effects Vinson et al. report are still lacking. Two recent studies, one from the Queen Margaret University in the UK (Revuelta-Iniesta. 2014), the other from the  Jiangxi Agricultural University in the People's Republic of China (Zheng. 2014) could now shed a little more light on the weight loss effects of green coffee beans and the combination of caffeine and cholorgenic acid (CGA), the allegedly most important active ingredient in unroasted, green coffee beans.

There is evidence of beneficial effects of GCA on your gut microbiome (Jaquet. 2009)

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In their 24-week rodent study, Zhang et al. (2014) tried to elucidate the mechanism by which CGA and caffeine regulate lipid metabolism. To this ends, they randomized their forty hairy subjects to diets containing no CGA or caffeine, CGA, caffeine, or CGA + caffeine.

Figure 1: Rel. (vs. control) body weight changes and liver and intraperitoneal adipose tissue weight (Zhang. 2014)

Over the course of the 24-weeks study, the scientists recorded body weight, intraperitoneal adipose tissue (IPAT) weight, and serum biochemical parameters of the rodents, tracked the the activities and mRNA and protein expression of lipid metabolism-related enzymes and analyzed the effects of caffeine, CGA and the combination of the two. What they found was...

1. 

   Figure 2: Effects of chlorogenic acid (CGA) and caffeine on the hepatic protein
   expression levels of AMP-activated protein kinase (AMPK), adipose TAG
   lipase (ATGL) and fatty acid synthase (FAS; Zhang. 2014)

   decreases in the body weight and IPAT weight of mice fed the CGA + caffeine diet,
2. significant decreases in the serum and hepatic concentrations of total cholesterol, TAG and leptin of mice fed the CGA + caffeine diet,
3. increases of the activity of carnitine acyltransferase (CAT) and acyl-CoA oxidase (ACO), 
4. decreased levels of fatty acid synthase (FAS) and the respective mRNA levels
5. significantly upregulated mRNA expression levels of AMP-activated protein kinase (AMPK), CAT and ACO
6. pronounced reductions of PPARg2

If we group these findings as follows 3 + 5 and 4+6, we could say that they triggered 1 + 2 by (a) increasing the oxidation of fatty acids (3+5) and (b) decreasing the synthesis and storage of fatty acids (4+6) - an observation that could certainly explain the benefits Vinson et al. observed in their human study which has been retracted in October 2014, though. On the other hand, the amount of CGA and caffeine in the rodent diets (0.2 % CGA + 0.03 % caffeine) was quite significant and previous rodent studies on other allegedly promising fat burners were not replicable in human beings either (example: CLA). Against that background it's good to have study #2 by R. Revuelta-Iniesta and E. A. S. Al-Dujaili, who investigated the effects of green coffee (GC), rich in chlorogenic acid, and black coffee (BC) on cardiovascular markers.

New human data with surprising results

The researchers designed a randomised pilot crossover study with healthy subjects who consumed both coffees for 2 weeks.

• The green coffee (GC) used in this project was Ethiopian Harrar 4 (100% Arabica) and the black coffee (BC) was Sainsbury’s Original Blend Cafetitère Coffee.
• The BC was  a blend of Brazilian, Colombian, Mexican, Nicaraguan, Peruvian, and Rwandan beans.

The study participants were asked to have 40 g of GC and BC per day distributed throughout the day into four cups of coffee. Thus, the scientists tried to ensure that high plasma coffee antioxidant concentrations were maintained over a period of time, "allowing effects to take place and the body to develop tolerance to caffeine, which can take 2-3 days." (Revuelta-Iniesta. 2014).

Table 1: Concentration of total polyphenols and antioxidant capacity determined in GC and BC as compared by the three methods of  coffee preparation (Revuelta-Iniesta. 2014).

The GC beans were grounded to powder using an electric coffee grinder. Instructions on how to make the coffee were provided and the Italian cafetière, the French cafetière, or the filter coffee machine was used to prepare the coffee drink.

The researchers measured anthropometry, blood pressure, and arterial elasticity after each intervention and collected urine samples to monitor antioxidant capacity. The free cortisol and cortisone levels you see in Table 2 were obtained from urine and analysed by specific ELISA methods.

Table 2: Comparison of results obtained (mean±SEM) after 14 days of green coffee vs. black coffee intervention (2-week cross over study); F: cortisol; E: cortisone; orange = almost bordeline significant; green = statist. significant inter-group difference (Revuelta-Iniesta. 2014).

In view of the short duration of the study (remember 2 weeks on each coffee), it's not really surprising that we didn't see changes in any of the anthropometric measures. On the other hand, the mere fact that the cortisol/cortisone ratio (indicating 11beta-HSD1 activity) was reduced after GC (from 3.5 +/- 1.9 to 1.7 +/- 1.04, P = 0.002) does not suggest that you will see beneficial effects on body composition in the absence of significant reductions in energy intake. A reduction in glucocorticoid activity can in fact hamper not accelerate weight loss (learn more) and the researchers hypothesis that "GC can play a role in reducing cardiovascular risk factors" (Revuelta-Iniesta. 2014) is a possible, but unconfirmed hypothesis.

Yes, agents like glycerric acid from licorice increase cortisol levels. Contrary to common believe this will yet not trash your testosterone levels and/or induce weight loss - quite the contrary | learn more

Bottom line: While the rodent study by Zhang et al. appears to support the accuracy of the data Vinson et al. published two years ago, you as a SuppVersity reader should be aware of the fact that the reduction in cortisol / cortisone activity Revuelta-Iniesta and Al-Dujaili observed in their subjects is not necessarily going to facilitate weight loss. As discussed in the corresponding Science Round Up, a normal circadian cortisol rhythm with both spikes and troughs is a prerequisite of optimal fat loss, so that it's suppression by green coffee beans or other means is beneficial only for those of us who suffer from chronically elevated cortisol levels.

Overall, we are thus left with a single study the whole "green coffee bean for weight loss"-hype is based on. Well, who cares. For the majority of best-selling supplements we don't even have that ;-)

References:

• Jaquet, Muriel, et al. "Impact of coffee consumption on the gut microbiota: a human volunteer study." International journal of food microbiology 130.2 (2009): 117-121.
• Revuelta-Iniesta, R., and E. A. S. Al-Dujaili. "Consumption of Green Coffee Reduces Blood Pressure and Body Composition by Influencing 11β-HSD1 Enzyme Activity in Healthy Individuals: A Pilot Crossover Study Using Green and Black Coffee." BioMed Research International 2014 (2014).
• Vinson, Joe A., Bryan R. Burnham, and Mysore V. Nagendran. "Randomized, double-blind, placebo-controlled, linear dose, crossover study to evaluate the efficacy and safety of a green coffee bean extract in overweight subjects." Diabetes, metabolic syndrome and obesity: targets and therapy 5 (2012): 21.
• Zheng, et al. "Chlorogenic acid and caffeine in combination inhibit fat accumulation by regulating hepatic lipid metabolism-related enzymes in mice." British Journal of Nutrition (2014). Ahead of Print.

GCB Another Fatloss Acronym: Green Coffee Bean Extract Helps Pre-Obese Men and Women Shed 16lbs in 22 weeks

Image 1: Coffee! Would you have recognized it?

HCG, GTE, GSE, DNP and obviously ECA! If you have ever done some research into pharmacological and non-pharmacological weight loss agents, you are probably familiar with this alphabet soup. But would you know right off your head what GCB stands for? No, ...? "G" as in "green", "C"  as in "coffee" and "B" as in "bean" - if you make it GCBE, with an "E" for "extract" it could make another item on your list of potential weight loss tools - moreover, one that has actual human data to back it up.

Green seems to be a good color for weight loss ;-)

In a recently published paper, a group of scientists from the University of Scranton, in the US, and the Health Sciences Clinic in Bangalore, India, report on the results of 22-week cross-over trial, in which the researchers tested the efficacy and safety of high (3x 350mg) and low (2x 350mg) doses of a commercial green coffee extract product (GCA by Applied Food Sciences; a 45.9% chlorogenic acid in an extract from unroasted = green coffee beans) in 16 overweight subjects (eight males and eight females; aged 22–46, mean age 33.19y; BMI 28.22km/m²). In each of the three arms of the studies, the subjects received the high and low dose supplement in a different order, so that the individual supplementation protocols looked like this:

• group 1: 6 weeks 3x 350mg / WA / 6 weeks 2x350mg / WA / 6 weeks placebo
• group 2: 6 weeks 2x350mg / WA / 6 weeks placebo / WA / 6 weeks 3x 350mg
• group 3: 6 weeks placebo / WA / 6 weeks 3x350mg / 6 weeks 2x 250mg
  * WA: 2-week wash-out period without supplementation

The results you see in figure 1, especially in the beginning of the study, are impressive, given the fact that the reduction in calorie intake (which is unfortunately not group-speficic) amounted to no more than -2% over the whole study period.

Figure 1: Mean weight over the whole 22-week study period and change in body fat percentage during the individual 6-week supplementation phases (data calculated based on Vinson. 2012).

It is yet somewhat suspicious that a) this phenomenon arose in both the high and the low-dose group (it was even more pronounced in the latter) and b) that the group which received the high dose in the beginning of the study experienced a profound "jojo-effect", when during the last 6-weeks, in which they received the placebo supplement.

Maybe helpful for the obese, but questionable for anyone who is already lean

Image 2: Coffee beans are not the only food (or raw material for a beverage) that loses some of its active and oftentimes healthy ingredients, when it is heated, or, as with coffee beans, roasted.

Moreover, the actual fat loss, which was measure only via one of those notoriously unreliable body impedance devices (SFB7 from Impedimed) is not exactly impressive and was statistically significant not only in the high and low dose, but also in the placebo phases of the trial (the 0.3% difference is laughable) left the subjects with still more than 23% body fat on their hips. So that, despite the existing evidence for the health and fat loss benefits of chlorogenic acid, I personally have my doubts that anyone with a dialed in nutrition and exercise regimen, would derive great fat-loss benefits from supplementing with two or three servings of this extract per day.

If you are yet still relatively chubby (the Peter Griffin type from the "Intermittent Thoughts") just interested in losing weight (an average of 16lbs or -10.5% in the study at hand) - and for the pre-obese individuals in the study at hand, this could actually be the case - GCB may really be an acronym to memorize, though.

Note: I stuck to the acronym GCB, also because it differs from the brand name of the patented "GCA" used in the study. After all, there is no reason to pay for the "A", when all you have to look for is a green coffee bean extract with a cholorogenic acid content of ~46% and a total chydroxycinnamic acid of ~57% (note: chlorogenic acid is in fact one of those chydroxycinnamic acids). And if you are not into popping pills, why don't you just make your own green coffee bean instant coffee - should work just as it is described in this guide on eHow for the regular, roasted variety... ah, and if you do, let me know how it tastes ;-)