Green Tea Extracts for Building Strength & Size and Losing Weight - Fact or Fraud? Or, Why It is Always Worth Taking a Look at the Data that Is NOT in the Abstract.

Image 1: If the watery green tea is healthy, then a potent extract must be even more healthy, right? This may well be just another instance of "supplementational idiocy"...

I know people love their Green Tea! After all, Camellia sinensis is one of the staples that has not yet been debunked as another hoax of the supplement of pharmaceutical industry - a real healthfood, right!? Well, you will probably be familiar with my skepticisms towards the notion that taking tons of the polyphenols you are "supposed" to get in relatively small quantities from 2-3 cups of green tea in supplemental form must necessarily be a good thing, just because epidemiological data suggests that people who consume green tea (for those who only now this stuff in capped form: Green tea is actually a beverage ;-) in moderation are overall healthier than people who abstain from drinking hot water extracts (=tea) from minimally oxidized (=green) Camellia sinensis leaves.

Did you miss my previous blogposts on the negative effects of high dose green tea extracts on testosterone levels and male fertility? If so, I suggest you read up on that one before adopting the (stupid) more-is-more principal and popping the whole box of green tea caps at once.

Two recent studies do confirm the notion that green tea, even as a supplement, may be a worthwile addition to your dietary (I suggest you drink the tea not use the supplement) or supplemental (if you cannot stand the taste of the brew) regimen. The first one comes from scientists from the University of Warsaw in Poland (Jówoko. 2011). In a small-scale study with 35 subjects, Ewa Jówoko and her co-workers investigated the effect of 1280mg of green tea polyphenols (from a standardized GTE supplement by Olimp Sports) had on the adaptational response to a standardized 4-week strength training regimen (cf. figure 1)

Figure 1: Summary of the study design - participant characteristics, training and supplementation regimen.

If you look at the summary of the study protocol in figure 1, you may notice that there are two factors which contribute to the real-world significance of the study. Firstly, the subjects followed a semi-standardized diet (90g protein; 270g carbs; 104g fat), because they had to eat at the University's cafeteria. Secondly, the training, as well as the supplementation protocol are similar to what a real beginner would be doing in the gym, when he strives to build lean muscle tissue. On the other hand, this also means that we will probably see different (I would bet even less pronounced) results in trained athletes / advanced strength trainees with an optimized diet and a highly sophisticated supplement regimen - so bare that in mind, when you interpret the following results.

Figure 2: Changes in back squat and bench press 1-RM max and repetition max after 4-weeks of strength training with and without GTE supplement (data calculated based on Jówoko. 2011).

It should not surprise you that 4 weeks of training led to increases in squat and bench press performance. The inter-group differences, as well as the increase in maximal repetition number on the bench, however, did not reach statistical significance. In other words, what we are seeing here are effects of the exercise regimen, independent of GTE supplementation.

Figure 3: Changes in blood pH, base excess and lacate subsequent to the initial (Term I) and post (Term II) muscular endurance and max strength tests (data calculated based on Jówoko. 2011).

Similarly, the changes in blood ph, base excess and lacate subsequent to the initial (Term I) and post (Term II) muscular endurance and max strength tests (cf. figure 3), were not statistically different between groups. But if you followed the SuppVersity news lately, you will already know that blood ph is the domain of plain baking soda... so why even bother with green tea in this regards? After all its not even supposed to be a H+ buffer, but a powerful anti-oxidant, so what we should see are decreased rates of oxidation...

Figure 4: Lipid hydroxyperoxides at rest, 5min and 24h after a strength and endurance test before and after the 4-week intervention (data based on Jówoko. 2011).

And in fact, if you take a very close look at the data in figure 3, you may be able to see (I highlighted the bar for you ;-) why the title of the study, "Green tea extract supplementation gives protection against exercise-induced oxidative damage in healthy men", is not totally off: The degree of lipid peroxidation at rest(!) remained constant (within statistical margin) in the GTE group, while it increased by +27% in the non-supplemented group. In view of the non-existent differences in terms of strength or endurance gains between the groups, it is yet very questionable whether this "protective" effect is worth the 16$ (based on the price of the original supplement used in the study that is only available in Europe) it would cost to mimic the supplementation regimen used in the study - especially for someone who does meet the dietary requirements for vitamin E, which is something the study participants with their cafeteria food didn't.

Scientific fraud in the name of marketing

The results of the second study, which investigated the effects of decaffeinated green tea extract (DGE: 2x530mg per day; 800mg catechins per day, total) on body weight changes in 69 overweight subjects (sedentary males, aged 40–69 years, with BMI > 28 and < 38 kg/m²) are similarly dazzling. In their abstract, A. L. Brown and his collegues from Unilever (do I have to say anything else) summarize the results of their 6-week placebo controlled cross-over study as follows (Brown. 2011):

Despite a similar increase in estimated energy intake during intervention period 1, body weight decreased by 0.64 (SD 2.2) kg and increased by 0.53 (SD 1.9) kg in the DGT and placebo groups, respectively (P< 0.025), suggesting a protective effect of green tea catechins on weight gain.

Does not sound earth shattering, but -0.6kg weight loss does at least appear to be more desirable than +0.53kg weight gain. But even if you do not have access to the full-text (as I do) and are thus able to debunk this as a blatant manipulation of the facts (which, by the way, is the result of selecting data from the more favorable 2 weeks of the 6-week study period), the standard-deviations of 2.2kg in the DGE and the 1.9kg in the placebo group should ring an alarm. If you do have the full-text, and take a closer look at table 3 (cf. excerpt)...

Table 1: Excerpt from table 3 in Brown, 2011

... you should start sensing fraud. After all, the table clearly states that the mean body weight loss over the whole study period was -0.038kg for the placebo and -0.327kg for the decaffeinated green tea group. If you now scroll a few pages down and read the last paragraph...

The authors are all employed by Unilever Research & Development, which is a division of Unilever plc, a company which has a significant commercial interest in tea. Unilever plc provided all funding for the study.

... it should become obvious that, even in the case of something as "innocent" as green tea, you better not believe everything you hear and read about "superfood" and respective extracts on the Internet. So, instead of buying decaffeinated capped bullshit from Unilever, you better go to your local grocery store, get yourself some quality green tea and make tea-time a relaxing part of your probably hectic daily routine ;-)

Green Tea Dose-Dependently Sheds 7%-20% Body Weight in Mouse Model, But Higher Doses Turn Out to Be Pro- not Anti-Inflammatory In Recent Tufts Study

Image 1: A cup of freshly brewed
green tea (photo by Wikimol)

Green tea is healthy, it gets you going, will make you lose fat and calm down inflammation... wait! Is it possible that all that was just another marketing scam? Scientists from the Tufts University in Boston (Pae. 2011) have now found that at least in case of the capped green tea extracts, health (over-)conscious GNC-consumers are popping like candy, these days, the latter, i.e. the anti-inflammatory effect is absent.

And, it even gets worse, higher doses of a standardized EGCG extract (TEAVIGO; 95% EGCG content) even increased inflammation (measured via proinflammatory cytokines in the blood of the animals) in a group of 6-9 months old pathogen-free male mice who had been fed a diet enriched with 1% of the extract for 6 weeks:

Contrary to the assumption that EGCG would reduce inflammatory response, mice fed 0.15% and 0.3% EGCG diet exhibited no change while those fed 1% EGCG diet produced more proinflammatory cytokines tumor necrosis factor-α, interleukin (IL)-6, and IL-1β and lipid inflammatory mediator prostaglandin E2 in their splenocytes and macrophages (MΦ) and less IL-4 in splenocytes.

In that, it is quite interesting that the cytotoxicity of the green tea extract didn't hinder it from unfolding its unquestionably more marketable potential to reduce body weight.

Figure 1: Body weight of ECGC treated in the course of the 6 week treatment period; expressed relative to the weight of the unsupplemented control group (data calculated based on Pae. 2011)

As the data in figure 1 indicates, all three levels of EGCG enrichment produced statistically significant and surprisingly instantaneous reductions in body weight. The mean weight difference to the control group were -7%, -12%, -20% for the 0.15%, 0.3% and 1% EGCG groups, respectively. Based on previous research on the weight loss effects of EGCG extracts, Pea et al. hypothesize that the underlying mechanisms "involve decreased energy/lipid absorption and lipogenesis",  "increased fat oxidation" and improved glucose tolerance. Since the authors of respective studies were interested mainly in the weight loss effect, they failed to measure inflammatory status, as well, which is why Peat et al. are unable to tell, whether these beneficial metabolic effects are associated or even stem from EGCG's effect on inflammation status.

To evaluate the potentially detrimental effects of the wide-spread use of commercially available green tea extracts, the authors conduct the following dose-equivalent calculation:

Based on the average mice's consumption of 3 g/days, diets containing the medium dose (0.3%), or 3 g EGCG /kg diet, provided mice with a daily intake of 9 mg EGCG, or 300 mg/(kg BW/d) for a mouse of 30 g (average BW in the current study). When this dose is converted from mice consuming 12 kJ/day to humans consuming 2000 kJ/day by using isocaloric calculation, it is roughly equivalent to 22 mg/(kg BW/day) in humans, or 1540 mg EGCG per day consumed by a 70-kg person. Likewise, the low dose (0.15%) and high dose (1%) of EGCG for mice in this study are equivalent to human daily consumption of 770 and 5040 mg, respectively.

In view of the fact, a cup of tea contains only 150−180 mg EGCG, it is unlikely that habitual green tea (~3-5 cup = 450-900mg EGCG) consumption will increase daily intake to the "critical" level of  commercially available EGCG - it could, on the other hand, suffice to induce beneficial effects on body weight, glucose management and fatty acid metabolism.

Did you know that in many studies concentrations of 50µmol/L, i.e. roughly 230,000mg of epigallocatechin-3-gallate per liter, were used to elicit the often cited health benefits of the green tea phytochemical? In animal models, however, even a dose of 2,000mg/kg body weight incresed plasma concentrations to levels slightly below 1/5th (9µmol/L) of what has been studied in the petri dish.

In case of the consumption of commercially available EGCG caps, which contain anywhere from 150-900 mg EGCG/tablet (depending on capsule size and purity of the extract), the more-is-more mentality of our society along with the desire to lose weight as quickly as possible could however lead to epigallocatechin-3-gallate intakes at levels equivalent to those that were achieved in the study and would thus leave consumers slim, but heavily inflamed. So, if you want to avoid that, you better stick to the suggested serving size (in case of the NOW Foods EGCG product, for example, this practice would deliver ~600mg in three divided doses per 24h), instead of going through your cost-effective 250g bottle of bulk 90% EGCG extract within a single month :-)