Endocrine Side-Effects of Athletic Competition: Is Power Lifting for Pussies and Canoeing for Real Men? Sports Specific Hormone Profiles - Cause or Coincidence?

With only one female power lifter and fewer female athletes for all sports, I didn't copy the hardly legible data for them, as well.

Some of you will remember the sneak peak of the results of a recent study designed to measure the "profile of hormones in a group of elite athletes" I gave you on Facebook a couple of days ago (read more). In case you do belong to the >4,500 people who already liked the SuppVersity Facebook Page, you will also remember that the observational study a group of Irish + British researchers conducted was meant to provide information about "what may be considered as normal" in a group of people among whom the use of hormones as performance-enhancing agents is widespread.

The research question M.J. Healy and colleagues from the St James’s Hospital, the Tallaght Hospital and the University of Exeter in Ireland and the UK tried to answer is thus: "What's actually normal for someone who's voluntarily exposing his body to hardships with profound endocrine side effects."

You can learn more about testosterone at the SuppVersity

High protein = low testosterone?

Low T, low life expectancy

Treat diabesity with testosterone

T-Gel + aromatase inhibitor?

D-aspartic acid does not boost T

Understanding testosterone

It goes without sayin' that the answer to this question is of particular interest for the WADA, the World Anti Doping Association. Whether it's also relevant for the average gymbro, on the other hand, is something I want to discuss in the bottom line of this article and thus after we've taken a closer look at the main results, of which the extremely low testosterone : estrogen ratio in powerlifters I already mentioned in the previously cited Facebook post is just one out of several curiosities.

Figure 1: Endocrine parameters relative to minimum (% above the bars) and maximum of reference range (bars) for men; the data is based on a barely legible table from the manuscript version and subject to correction (Healy. 2014)

Curiosities and abnormalities, of which it's often hard to tell, whether they are brought about by the certain training techniques or physical demands of the corresponding sport, or it is just the other way around, and athletes with certain baseline hormone profiles chose specific sports because their endocrine programming is particularly conducive to high performance in their specific sporting discipline.

In a totally different context, Maïmoun et al. (2014) have only recently been able to show that the endocrine profile of female swimmers "was characterized by significantly increased serum T levels (0.56 ng/mL, vs 0.39 ng/mL for controls) - to be precise, "[s]eventy-two percent of these swimmers presented T values higher than 0.5 ng/mL, characterizing this population as hyperandrogenic" (Mïmoun. 2014). A percentage that's high enough for the French researchers to conclude that...

"[...] in these female athletes is perhaps not coincidental (16). A predisposition to hyperandrogenism might orient girls toward sports like swimming, where strength is a performance criterion." (Maïmoun. 2014)

Whether a similar explanation could be given for the extremely low testosterone levels of the powerlifters is highly questionable. There is after all no sex-difference in respect to the impact and importance of testosterone in strength sports that would dictate that women need abnormally high testosterone and abnormally low estrogen levels, while men need low testosterone and high estrogen levels for maximal strength performance.

Apropos men and women: There are similar extremes

If we stick to the analysis of abnormal testosterone levels, it appears as if excursions to both extremes are about equally likely in men and women, with...

• 16.5% of the male athletes suffering (?) from serum testosterone levels below 8.4 nmol/l, the lower limit of the normal reference range (Bayer. 2013), and 
• 13.7% of the female athletes exposing testosterone levels greater than 2.7 nmol/l, the upper limit of the normal reference range (Bayer. 2013)

... it's obvious that "normal" is a relative term, when it comes to the "Big T" levels of  elite athletes during / after competitive events.

Doping excluded: With one exception, all athletes with low testosterone levels had normal luteinizing hormone (LH) levels - a clear indicator that they were not using performance enhancing drugs like trenbolone, or nandrolone, which would obviously crush both, the T- and LH-levels.

For the women with testosterone levels above the normal range (> 8.3nmol/l) the scientists observed significant differences in fat mass, height, estradiol fT3, fT4, %body fat, BP2, Osteocalcin and IGF-I. Specifically, the women with elevated testosterone levels were...

• taller and thinner, 
• had lower estradiol, IGF-1 and osteocalcin levels, but
• increased free T3, free T4 an IGFBP2 levels

In both groups, men and women, the outliers were predominantly younger athletes. In view of the fact that there is no suitable control group or age-specific reference data in athletes, we have to be very careful about drawing far-reaching conclusions based on data from this "high T outliers".

Sport is not just one, it's the most significant determinant of endocrine disturbances

Irrespective of the fact that we have to be similarly cautious on the other end of the high vs. low testosterone level divide, the mere age-difference between the oldest athletes, the power lifters, and the youngest, the swimmers, is similarly unsuited to explain the differences I plotted in Figures 1-2 (note: I decided against plotting the data for the female athletes, because (a) the table was even harder to read and (b) the number of athletes in many sports was very low), as the height (basketball players were the tallest and the power lifters the shortest) and weight differences (contact sports like ice hockey, handball and basketball had the highest BMI while cross-country skiing the lowest). In fact, Healy et al. found only two instances where age alone could account for the differences between sports (IGF-BP2 and IGF-BP3 in women).

Figure 2: Power lifters don't even have the lowest testosterone : estrogen ratio, track & field athletes are - assuming that I deciphered their estrogen levels correctly, even worse off (Healy. 2014)

Overall, there were fewer significant differences in hormone levels between groups among the female athletes (Table 3b) but this is most likely due to the smaller numbers of volunteers in many of the groups as the pattern between sports seems quite similar. This takes us back to where we came from. As surprising as it may sound: At least in men, the predominant factor for inter-athlete differences is the category of sport the corresponding athletes are competing in. As Healy et al. point out, here are a number of recognisable patterns and many unexpected:

"For example, there was the inevitable relationship between height, weight, body fat, lean body mass (LBM) and BMI. Weight correlated very closely with BMI which in turn correlated less closely with LBM, body-fat and height. For LBM and body-fat the relationship with BMI is distinctly different between the sexes reflecting the increased body fat in women at all levels of BMI." (Healy. 2014)

And while I know that you would probably like to hear more about the underlying mechanisms, an observational study like the one at hand simply doesn't allow for a detailed analysis of the general mechanism behind this complex network of changes.

High / low testosterone not a performance factor? Because the samples were anonymized it's not possible to tell whether there significant correlations between high or low hormone levels and the overall success of the athletes in the events, but in view of the fact that all athletes, overtrained or not, successfully competed at national or international level. The study at hand does, as Healy et al. point out "indicate that serum testosterone does not determine athletic performance" and will thus add "another 'nail in the coffin' for the strange IAAF/IOC definition" of normal values for testosterone - specifically in female athletes (IOC).

Let's get back to the T:E ratio: In view of the fact that there is remarkably little information published in peer-reviewed journals concerning hormonal profiles in elite athletes. It's hard to compare the data from the study at hand to previous data in a way that would allow definite conclusions.

It is thus not clear why there are so many low testosterone values in men and why they occur particularly often in power lifters. Their body fat levels are higher than those of the other athletes, which ~17% yet still far away from those levels, where the increased aromatization (=conversion of testosterone to estrogen; learn more) becomes a problem. The psychological stress from the event should have been similar in all athletes and the physiological demands would suggest lowered testosterone levels particularly in aerobic sports, which are well-known for their association with functional hypothalamic hypogonadism, stress fractures and reduction in serum testosterone (Bennell. 1996). Moreover, even physical strain as observed in army personnel on a combat course also leads to a dramatic fall in testosterone to very low levels that recover rapidly after a good night's sleep (1978).

References:

• Aakvaag, A., et al. "Hormonal changes in serum in young men during prolonged physical strain." European journal of applied physiology and occupational physiology 39.4 (1978): 283-291.
• Bayer Diagnostics. Total (Serum) Testosterone by Advia Centaur System (2013). Ref Type: Online Source: labmed.ucsf.edu/labmanual/db/resource/Centaur_Testosterone.pdf  
• Bennell, Kim L., Peter D. Brukner, and Susan A. Malcolm. "Effect of altered reproductive function and lowered testosterone levels on bone density in male endurance athletes." British journal of sports medicine 30.3 (1996): 205-208.
• Healy, M. L., et al. "Endocrine Profiles in 693 Elite Athletes in the Post‐Competition Setting." Clinical endocrinology (2014).
• IOC Regulations on Female Hyperandrogenism (2012). Ref Type: Internet Communication: www.olympic.org/Documents/Commissions_PDFfiles/Medical_commission/2012-06-22-IOC-Regulations-on-Female-Hyperandrogenism-eng.pdf
• Maïmoun, Laurent, Neoklis A. Georgopoulos, and Charles Sultan. "Endocrine Disorders in Adolescent and Young Female Athletes: Impact on Growth, Menstrual Cycles, and Bone Mass Acquisition." The Journal of Clinical Endocrinology & Metabolism (2014).

Can 5 Cups of Coffee Boost Testosterone to Estrogen Ratio in Overweight Men Transiently by ~200%? Plus: SHBG Its Own Receptor and Its Role in Prostate & Breast Cancer

Testosterone booster in men and estrogen amplifier in women? As if there were not already enough good reasons to get your daily dose of the 'kingly' brew ;-)

You would not have to be a diligent student of the SuppVersity to know: Coffee is a truly remarkable brew. Even mainstream media has gotten wind of the multitude of beneficial effects a moderate intake of the former drink of the kings and popes can have on your health and if it was not for the authors and newscasters blind reliance on whatever the press release guys are telling them, it would probably not even have been necessary for me to broach the beneficial effects coffee can have on your metabolic health and overall well-being in posts like "Coffee - 3 Cups a Day Keep Insulin at Bay", "Pre-Workout Caffeine: Fat Liberator, Substrate Modulator, Trans-Fatty Acid Eliminator & Performance Upregulator!" and many more.

So what is it this time? What else can coffee do for you?

I guess something only few people others than SuppVersity readers will be aware of is the fact that caffeine  and therefore coffee makes a nice testosterone booster (Beavon. 2008; study was discussed briefly as part of a longer post on June 20, 2012 an mentioned previous times in other posts) -- at least if you stick to moderate doses of ~300-400 mg before a workout. So, unless you are a newbie or missed the respective news, you should not be surprised that a recent study from the Harvard School of Public Health (Wedick. 2012), which had actually been designed mainly to investigate the effects of 5x 6-ounze cups caffeinated and decaffeinated coffee (both instant coffees; brand: Nestlé’s Taster’s Choice) on serum levels of sex hormone-binding globulin (SHBG), found that the consumption of both 'real' and 'fake' (=decaffeinated) instant coffee did lead to increases in total and free testosterone and profound decreases in estradiol (bound and free).

Figure 1: Levels of SHBG, testosterone, free testosterone, estradiol, free estrogen, the testosterone to estrogen ratio and DHEA in the male participants of the study expressed relative to a caffeine abstinent control group (Wedick. 2012)

As the data in figure 1 goes to show these changes were unfortunately transient and the impressive +189% increase in the testosterone to estrogen ratio which occurred during the first month of treatment totally disappeared within the next four weeks. On the other hand, the effects on SHBG the scientists had expected based on the assumption that both SHBG and caffeine intake have been found to be associated with lower risk of type II diabetes in large epidemiological studies, was non-existent in the first and second 4 weeks of the study... at least in the male subjects who were all overweight, nonsmokers and habitually coffee consumers, who had been required to abstain from caffeine intake for at least 2 weeks before the study was conducted.

Figure 2: Levels of SHBG, testosterone, free testosterone, estradiol, free estrogen, the testosterone to estrogen ratio and DHEA in the female participants of the study expressed relative to a caffeine abstinent control group (based on Wedick. 2012)

If you take a look at the data from the female participants (likewise overweight non-smokers, habitual caffeine consumers and, at the beginning of the study, 'dried out'; see figure 2), a different image emerges, in the women we do in fact see a transient rise in SHBG, which goes hand in hand with a decrease in testosterone, de to which the T/E ratio drops by -36% and -54% in the groups drinking caffeinated and noncaffeinated coffee respectively. Just as in their male counterparts, the levels did go back up in the second part of the study so that all values, including the SHBG levels were back in to normal after 8 weeks (please note changes in the 20% range are irrelevant and could be due to having a meal before the test, bad sleep, whatever).

The relative data tells only part of the story

Figure 4: Absolute values of the testosterone to estrogen ratio after 4 and 8 weeks; baseline levels were 16.2, 15.8, 18.2 in the caffeinated coffee, decaffeinated coffee and control group respectively. The data clearly shows: Coffee needs a PCT ;-)

If we do now take a closer look at the actual data and discard the comparison to the control group the scientists the picture becomes even more complex. After all the data in figure 4 clearly indicates that we are dealing with a combined effect here. It is correct that the ingestion of the caffeinated beverage had pronounced effects on the T/E ratio especially in the male participants, what the data in figure 1 does yet not tell you is the fact that this effect was also so pronounced, because simply stopping to drink caffeine reduced the T/E ratio from 18.1 to 8.4, i.e. by 54%(!).

Now this certainly reduces the effect size, but it does not totally negate the effect. After all the 'real' coffee drinkers (w/ caffeine) did still increase their T/E ratio from 16.2 to 24.2 -- a certainly likewise noteworthy increase of +29% that is however still far away from the exorbitant +189% increase compared to the poor guys who did not just lose their coffee, but also their virility.

So what does this tell use?

How cares about SHBG anyways? You should! After all there is relatively conclusive evidence that normal (not exorbitantly high!) SHGB levels have a protective effect against breast cancer in women and mechanistic evidence that they increase the risk of prostate cancer in men. In both cases SHBG acts independently via the largely ignored SHBG receptor that modulates the action of estrogens. Co-activation of SHBG and estrogen receptor in the prostate induces similar effect on prostate specific antigen secretion as DHT (Nakhla. 1997). Since estrogen alone does not have this effect, it is no wonder that stinging nettle root (Urtica dioica), with its SHGB inhibiting effect is a viable tool in the treatment of benign prostatic hyperplasia (Hryb. 1995). In the female breast, on the other hand, SHBG seems to " trigger a 'biologic' anti-estrogenic pathway" (Fortunati. 1999) and does therefore exert anti-instead of pro-carcinogenic effects.

I guess there are more than just the following three lessons to learn from this study, but at the moment these appear to be the most important ones for me:

1. The beneficial effects habitual coffee intake has on type II diabetes risk are, contrary to the scientists hypothesis, not mediated by its effect on SHBG.
2. In overweight men caffeine has a very shortlived beneficial effect on testosterone and the testosterone to estrogen ratio. After 4 weeks the levels do yet return to baseline, so this cannot explain the long-term benefits of habitual caffeine consumption either (maybe you should cycle caffeine instead of testosterone booster < I am just kidding ;-).
3. In overweight women, there is a similar, yet negative effect on testosterone levels, which is likewise transient and lasts less than 8 weeks. 
4. The caffeine ads to the 'pro-testosterone' effects, but even decaffeinated coffee has some effects.
5. Stopping "cold turkey" is not a good idea, when you are "on caffeine"

Now, what is important here is that we are dealing with overweight individuals, in whom the endocrine millieu is usually off. In particular, men tend to have reduced, women tend to have increased androgen levels (think PCOS). The effects we see after short-term withdrawal and the subsequent consumption of a non-negligible amount of 5 cups of coffee everyday could actually have corrective effects on the endocrine milieu, of which both, men and women could benefit, if they would last for more than 4-6 weeks. The detrimental effects of stopping, on the other hand, could be due to the sudden absence of the benefits of caffeine.

Regardless of whether you stop or start drinking coffeine, the endocrine "disturbances" are relatively short-lived and only further testimony to the fact that our bodies will always try to find a new "steady state" in what they consider normal.

Bottom line: There are a myriad of good reasons to drink coffee, getting more manly or more feminine is yet not one of them. Disappointed? Well, on the other hand this means coffee is no endocrine disruptor - and at least in this overweight population it seems to have a marginally beneficial baseline effects (thus the detrimental effects of abstinence).

References:

• Beaven CM, Hopkins WG, Hansen KT, Wood MR, Cronin JB, Lowe TE. Dose effect of caffeine on testosterone and cortisol responses to resistance exercise. Int J Sport Nutr Exerc Metab. 2008 Apr;18(2):131-41. 
• Fortunati N, Becchis M, Catalano MG, Comba A, Ferrera P, Raineri M, Berta L, Frairia R. Sex hormone-binding globulin, its membrane receptor, and breast cancer: a new approach to the modulation of estradiol action in neoplastic cells. J Steroid Biochem Mol Biol. 1999 Apr-Jun;69(1-6):473-9.
• Hryb DJ, Khan MS, Romas NA, Rosner W. The effect of extracts of the roots of the stinging nettle (Urtica dioica) on the interaction of SHBG with its receptor on human prostatic membranes. Planta Med. 1995 Feb;61(1):31-2.
• Nakhla AM, Romas NA, Rosner W. Estradiol activates the prostate androgen receptor and prostate-specific antigen secretion through the intermediacy of sex hormone-binding globulin. J Biol Chem. 1997 Mar 14;272(11):6838-41.
• Wedick NM, Mantzoros CS, Ding EL, Brennan AM, Rosner B, Rimm EB, Hu FB, van Dam RM. The effects of caffeinated and decaffeinated coffee on sex hormone-binding globulin and endogenous sex hormone levels: a randomized controlled trial. Nutr J. 2012 Oct 19;11(1):86.

Measuring Overtraining; Phosphatidic Acid to Potentiate the mTOR Effects of Leucine? Plus: Built-in Serm in Menopausal HRT Blocks Breast Cancer, Creatine Bumps Up Performance Not Body Weight, Estrogen Timing & Brain NDMA Toxicity

Weight-supported sports such as cycling precipitate overtraining

"20%", that's the SuppVersity figure of the week. It tailors directly to the first item in today's installment of On Short Notice and denotes the amount of professional athletes who exhibit symptoms of overtraining syndrome at any given time in their career.

"The prevalence varies by sport and is thought to be highest in endurance sports requiring high volume intense training, such as swimming, triathlon, road cycling, rowing and, to a lesser extent, distance running."  (MacKinnon. 2000)

What all those sports (except for distance running) have in common are long training hours on 6 days per week for several months without appreciable time off. Notably, the chances of overtraining also increase, when the equipment supports your body mass. With weight-bearing activities, such as distance running, on the other hand, the risk of musculoskeletal injury limits training volume and therefore reduces the chance of "running" (literally) into overtraining.

Overall, there is however no group of athletes that is immune to training too long, too hard and without appropriate recovery times. And yes, this goes for power sports, such as weight lifting and judo, as well (cf. Callister. 1990, Fry. 1994)!

Identifying overtraining by psychomotoric evaluation  

When you come to think of it, it does actually stand to reason: Static and dynamic tasks for finger, hand, and arm movements, as they are assessed during a  series of tests to assess motor performance are a way better yardstick to determine the stress (over-)load on the central nervous system (CNS), than simply looking at "how much ya bench". Why? The nasty, creepy and easy to overlook form of overtraining happens largely in your head and your nerves, it's not muscular. Your skeletal muscle can be fully rested, while your central nervous system is at the verge of collapsing.

What does the motor-skill test measure? (1) steadiness (one or both hands) - assesses hand unrest, tremor; (2) inserting long pins (one or both hands) - assesses rate of arm and hand movements, precision of arm-hand movements, manual and digital dexterity; (3) tapping (one or both hands) - assesses wrist-finger speed

Usually the latter goes hand in hand with other not exactly exercise related stress symptoms such as nervousness, and the inability to cope with the imposed stress and piling-up difficulties. Therefore Paul et al. required that all the one-hundred 18-25y athletes (M=65, F=35; university to international level) from various athletic backgrounds, i.e.

• hockey (14%), volleyball (14%), basketball (13%), handball (12%), football (6%), cricket (2%),
• cycling (13%),  running (11%), kabaddi (8%),  swimming  (5%),  gymnastics (1%), and sprinting (1%)

to fill out a "classic" Training Stress Scale (TSS) questionnaire as well. The TSS is a 19-item scale to check the symptoms of acute overtraining which includes a subset of questions designed to assess  the ability of bouncing back mentally after setbacks and mistakes (REB).

Figure 1: Motor performance (steadiness error duration; inserting long pins task duration; tap hits) in 100 athletes grouped into low (LS), medium (MSG), and high (HSG) groups according to their scores on the TSS test (calculated based on Paul. 2012)

As you can see in figure 1 the results of the motor performance test did not just correlate with the data from the stress test questionnaire, they also depict a very good picture of the state of the nervous system, with highly significant difference between the highly stressed and almost certainly overtrained athletes (green) and their lightly stressed peers (figure 1, blue; stress data was assessed by the aformentioned TSS test).

Professional athletes rarely end up  like Christian Bale in the Machinist but as I discussed at length in a previous post, overtraining was one of the two pillars of the crazy regimen the actor used to starve himself into a state that hardly allowed him to perform in front of the camera.

Aside from the high correlation and the confirmation of the hypothesis that psychomotoric tests could prove a valid tool to access the training status of athletes and ambitious gymrats, the investigation yielded the following main results:

• The athletes with lowest training stress symptoms showed the highest reboundability (resilience) from their mistakes. 
• Increased intensity of training stress symptoms indicates attention deficit leading to poor psychomotor performance.
• Along with physical training, psychological training has to be considered as one of the eminent aspects of overall development of an athlete.

In order to maximize athletic performance, it is therefore more or less obligatory to "carefully and timely diagnose for any signs and symptoms for physical and psychological distress" (Paul. 2012). Needless to say that the combination of the TSS and psychomotor performance test offers a way to do just that - to monitor, control and optimize the training routine.

Phosphatidic acid a novel 'mTOR potentiator' for superior gains?

I somehow forget this one in the last installment of On Short Notice, but before the first supplements are going to hit the market (two of the authors have already filed a patent back in 2011 that hasbeen  published in June 2012; see De Ferra. 2012), I thought I'd briefly discuss the results of a recently published study on the potential ergogenic and muscle building effects of phosphatidic acid (PA) by Hoffman et al. (Hoffman. 2012).

The study that was published online in the Journal of the International Society of Sports Nutrition evaluated the effects of an 8-week resistance training on 16 resistance-trained men who had been randomly assigned to consume either 750 mg of PA or a placebo.

Figure 2: Effect of 8 weeks of strength training + post-wporkout amino acid supplementation with and without  750mg phosphatidic acid  per day (left) and ratio of beneficial, trivial and negative effects of supplementation on the respective outcome parameters (Hoffman. 2012)

As the data in figure 2 goes to show you, the supplementation regimen had beneficial effects almost all of the (except for the pennation angle, btw. where greater the angles of pennation, means translates to a smaller amount of effective force transmitted to the tendon), however not a single statistical significant difference was observed. And while the scientists assessment that the overwhelmingly beneficial effect of PA supplementation on lean mass gains is "very likely beneficial", this does not change that the 750mg of PA did not add to allegedly highly beneficial effects of the workout regimen.

Figure 3: Training protocol and amino acid content (in g/100g) of the post-workout supplement (identical in both groups).

Since all particpants had taken part in identical 4-day per week, split routine resistance training programs for 8-weeks (70% of their 1-repetition maximum (1-RM) for all exercises;  90-s rest period was required between each set, for all exercises; for the exercises check out figure 3) and were advised to consume a standardized post-workout protein formula (containing 36-g amino acid and collagen protein blend) mixed in a 500 ml commercial sports drink within 30 minutes post-exercise, the supplemental confounding factors were pretty tightly controlled. If anything but the consumption of the PA supplement would have been responsible for the inter-group differences this would therefore have to be related to

• the non-supervised training sessions at the subjects respective local gyms (training logs regardless of whether they are evaluated by "certified personnel", or not, can obviously be faked), and
• the absence of a prescribed nutritional regimen (the participants kept 3-day food-logs and were advised to stay on their habitual diet; no significant differences in total intake ~3,200kcal/day; according to Hoffman et al. likewise not statistical significant, but wrt to the the changes in body composition maybe noteworthy, were the -17% lower carb and +18.2% higher protein intake in the active = PA arm of the study)

Both the missing supervision, as well as the absence of a fixed nutritional protocol would however pertain to both groups and are thus likely to average out. Plus, they actually make the study more realistic. After all, you are interested in what happens if the average strength trainee (in this case young men with a mean age of ~23years, at least 1 year of training experience and a BMI of 27.7kg/m²) and not to 10 identical clones, don't you?

"So this stuff is not useful, right?"

Figure 4: Exogenous phosphatidic acid is metabolized to lysophosphatidic acid (LPA) in the body and LPA has been shown to work synergistically w/ leucine to increase mTORC1 activity (in vitro data from Winter. 2010).

Despite the "likely" and "very likely beneficial" effects on lower body power and lean body mass, of which only the latter could maybe have reached statistical significance with a larger number of participants (with only 20 subjects, i.e. 10 per group differences need to be more pronounced to reach statistical significance). It should be quite obvious that PA is probably not the next creatine.

Maybe the increased mTORC1 expression Winter et al. have observed upon co-incubation of leucine with LPA are not pronounced enough (figure 4). Or simply not necessary with enough leucine and insulin in the blood stream. After all, the Winter study also showed that basically identical effects were observed when the cells were incubated with leucine + insulin, instead of LPA + insulin (data not shown in figure 4).

So even if oral PA acts just like in-vitro LPA synergistically with leucine to activate the mTOR pathway (Fang. 2001; Winter. 2010; figure 4), the real world benefits in the study at hand are probably about as significant as the hypothetical 500g increase in net protein retention I discussed in he protein timing news earlier this week. Whether this may change with higher and/or more frequent doses in future studies remains to be seen, though. It does at least not appear to be impossible...

Additional news

• 'Built-in SERM' could help making post-menopausal estrogen replacement breast cancer proof At least this is what the results of a recent rodent trial that was conducted by researchers from the Division of Endocrinology at the Department of Medicine of the University of Virginia Health System in Charlottesville would suggest. Even in the absence of a progestin, which does have some ameliorative effects on the pro-carcinogenic effects of estrogen, the addition of the tissue-specific selective estrogen receptor modulator bazedoxifene (BZA) to the allegedly questionable, yet still widely prescribed conjugated equine estrogen (CEE) blocked the CEE- and, in a second control study, even the more potent E₂-stimulated ductal and terminal end bud growth of mammary gland and the corresponding estrogen-responsive gene expression (Song. 2012). 

• 

  Just like any athlete, man or woman who is interested in increasing his / her athletic performance, German Olympic lifter Julia Rohde could benefit from taking regular creatine monohydrate without necessarily running the risk of having to compete in a higher weight class (img sportzentrum-flora.de)

  5g creatine monohydrate (CM) per day helps soccer players to improve their game - or, more precisely, the time they needed to complete a standardized sprint running and dribbling test. And while you will probably not be surprised that CM supplementation did not affect the accuracy of their shots, you may very well be surprised that it did neither induce greater weight gain or any other changes in body composition (Mohebbi. 2012).
  
  The latter may also be interesting for athletes competing in sports where increased muscle mass can become an issue. After all, the results Mohebbi et al. present in the latest issue of the Middle-East Journal of Scientific Research would suggest that unless your training is geared towards increased muscle gain (which is obviously shouldn't be if that would be an issue for you) regular creatine, i.e. not the sugar laden 'cell-volumizers', can help you increase your performance - and the 2kg extra-weight the players gained, obviously weren't disdisadvantageous for them.
• Whether estrogen will save your brain cells or actually exacerbate the damaging effect of NMDA exposure depends on timing I guess you will all have heard of the protective effects of estrogen against N-methyl-d-aspartate (NMDA) toxicity. Now, a group of researchers from the University of Catania and the University of Rome Sapienza,both obviously in Italy, found that only pretreatment with estrogen will provide these beneficial effects, while the co-incubation or subsequent administration of estrogen will only potentiate the NMDA-induced cell death (Spampinato. 2012)

Have a nice weekend, everyone! As far as the On Short Notice items go, that's it for today. If you want more, just check out the SuppVersity Facebook Wall. I must forewarn you, though, since I am pretty busy this weekend, I am not sure if there will be another installment of the Athlete's Triad Series, tomorrow. If that's not the case, you will however get a regular news item, so don't worry you won't get bored ;-)

References:

• Callister R, Callister RG, Fleck SJ, Dudley GA. Physiological and performance responses to overtraining in elite judo athletes. Med. Sci. Sports Exerc. 1990; 22: 816–24.
• Fang Y, Vilella-Bach M, Bachmann R, Flanigan A, Chen J: Phosphatidic acid-mediated mitogenic activation of mTOR signaling. Science 2001, 294:1942–1945.  
• De Ferra L, Heuer M, Hagerman S, Purpura S, Jäger R. Method for increasing muscle mass and strength. Filed November 23, 2011. US 2012/0141448 A1. Published on June 7, 2012.
• Fry AC, Kraemer WJ, van Borselen F et al. Performance decrements with high-intensity resistance exercise overtraining. Med. Sci. Sports Exerc. 1994; 26: 1165–73. 
• MacKinnon LT. Special feature for the Olympics: effects of exercise on the immune system: overtraining effects on immunity and performance in athletes. Immunol Cell Biol. 2000 Oct;78(5):502-9.
• Mohebbi H, Rahnama N, Moghadassi M, Ranjbar K. Effect of Creatine Supplementation on Sprint and Skill Performance in Young Soccer Players. Middle-East Journal of Scientific Research. 2012; 12 (3): 397-401.
• Paul M, Khenna N, Sandhu JS. Psychomotor analysis of athletes under overtraining stresss. Serb J Sports Sci. 2012;6(3): 95-10.
• Song Y, Santen RJ, Wang JP, Yue W. Effects of the Conjugated Equine Estrogen/ Bazedoxifene Tissue-Selective Estrogen Complex (TSEC) on Mammary Gland and Breast Cancer in Mice. Endocrinology. 2012 Oct 15.
• Spampinato SF, Merlo S, Molinaro G, Battaglia G, Bruno V, Nicoletti F, Sortino MA. Dual Effect of 17β-Estradiol on NMDA-Induced Neuronal Death: Involvement of Metabotropic Glutamate Receptor 1. Endocrinology. 2012 Oct 17.
• Winter JN, Fox TE, Kester M, Jefferson LS, Kimball SR: Phosphatidic acid mediates activation of mTORC1 through the ERK signaling pathway. Am J Physiol Cell Physiol 2010, 299:C335–C344.

+87% Increase in Testosterone Within 21 Days from a 100% Natural Supplement? Study Shows: Soy Bean Extract Can Do Just That While Wreaking Havoc on Your Testes. Plus: Corn Oil Reduces Testosterone to Estrogen Ratio by -50%!

Image 1: I guess the feed of those boars does not contain any corn oil and is spiked with both bisphenol A and soy bean extract - I mean, how else could you possibly explain those balls? (img dirtybutton.com)

Let me start today's post with a few questions: Would you buy a 100% natural product that can lower your estrogen levels by up to -98%, increase the weight of your testes by ~30% and, above all, boost your testosterone levels by a whopping +87%? I guess, at least all those of you who either have not read or not understood the Intermittent Thoughts episode on estrogen's role in skeletal muscle hypertrophy are just sitting there, nodding their heads... I would yet also venture the guess that this nodding will end pretty abruptly, now that I am about to tell you that this all natural testosterone booster is derived from the powder of 2kg of Glycine max soy beans via methanol extraction, subsequently freeze dried and capped into 600mg caps of which the average adult (~80kg body weight) is supposed to ingest two per day.

Chose your poison: BPA, soy, or maybe just some governmentally subsidized corn oil?

The preceding paragraph was an ironic, yet as far as the underlying facts and figures are concerned 100% accurate introduction to today's post which revolves around a study Evanski from the Mind&Muscle forum has brought to my attention (Norazit. 2012). The authors, a group of scientists from the University of Malaya in Kuala Lumpur, Malaysia, had set out to investigate the purportedly negative effects of what they call "soya bean extract" (interestingly this spelling of "soy", which is identical to the German version is probably the reason the study did not appear on my "interesting stuff for the SuppVersity radar", before ;-), bisphenol A, 17β-estradiol and "harmless" corn oil on the testis and endocrine system of juvenile rats.

Figure 1: Phytoestrogen content (µg/g dry weight; mind the logarithmic scale!) of soy bean extract an standard rat chow measured by LCMS (data adapted from Norazit. 2012)

To this ends, the scientists divided thirty 21-day old juvenile male Sprague-dawley rats (=the standard lab rat) into five groups, receiving either a standard diet (which contained an insignificant amount of soy, cf. figure 1) + 100mg/kg Tween 80 (a standard food emulsifier with derived from polyethoxylated sorbitan and oleic acid; this group served as control for the soy and the bisphenol group) or standard diet +100mg/kg of corn oil (Mazola; this group served as a control for the estradiol group because the 17b-e did not dissolve in the Tween 80), soy extract, bisphenol A (Aldrich Chemical Co.) and 17b-estradiol (the most active form of estrogen, which binds to both the alpha- and beta-receptor) for three weeks.

Note: It is (at least in my view) a lucky coincidence that contrary to the soy extract and the bisphenol, the estradiol did not solve in the Tween 80, so that the scientists had to come up with Mazola corn oil as a "positive control". I mean, if you take a look at the effects this supposedly neutral "solvent" had on the endocrine milieu of the peripubertal rats, it is no wonder that with the average testosterone levels of the male inhabitants of the #1 corn producer of the world, the Unites States of America, is on a constant decline.

At the end of the study period the rats were sacrificed, the testis were excised and their testosterone and estrogen levels were assessed using standardized enzyme immunoessay (EIA) kits from Caymen Chemical.

Figure 2: Section of seminiferous tubules from control Tween 80 group, BPA group and soy bean extract group; (1) maturing spermatids, (2) lumen filled with cellular debris, (3) vacuaolation, (4) interruption of spermatogenesis (data adapted from Norazit. 2012)

Even a layman can see that both the bisphenol A, as well as the soy bean extract treatments induced profound changes in the cell-morphology of the testes (cf. figure 2). Vacualation (3), i.e. formation of vacuoles in cellular tissue, was present in both, only the bisphenol A group showed the characteristic lumen filled with cellular debris (2). Visible signs of spermatogenesis (1) were visible in neither of the groups, a clear interruption of the latter (4), was yet observed only in the soy and the estrogen group (latter not shown in figure 2). Moreover, the estrogen treated animals were the only ones where the testis showed clear signs of apoptosis (cell death).

The "harmless" corn oil shifts the testosterone to estrogen ratio from ~1/1 to 1/2pg/ng

Reckless, as I am I decided to discard Norazit et al.'s distinction into the BPA and soy groups with the Tween 80 group as a control and the estradiol group with their corn oil control and just plotted the total body and total and relative testis weight gain, estrogen and testosterone levels relative to the Tween 80 group. In other words, I treated the corn oil group as if it was just another treatment group. This is obviously somewhat fishy, but if no scientist appears to be willing to investigate the potential negative effects of corn oil on the endocrine system of adolescent rodents (let alone humans), this is the only way for us to get respective data ;-)

Figure 3: Body weight gain, total and relative right testis weight, estradiol and testosterone levels in peri-pubertal rats after 21 days on diets containing 100mg/kg bisphenol A, soy bean extract, corn oil or 17b-estradiol (in soy bean oil); data expressed relative to Tweenn 80 (polysorbate + oleic acid) control (data calculated based on Norazit. 2012)

And if you take a look at the data in figure 3 (the vertical axis of which is by the way discontinuous!) it becomes clear that you better feed your boys a food solvent such as Polysorbate 80 (=Tween 80) than the "healthy" corn oil the US government is trying to con you into. After all, the administration of 100mg/kg corn oil (human equivalent ~16mg/kg) during puberty decreased the testis weight of the rats by -23% it reduced the amount of estradiol by -35% and the amount of testosterone by -66% and thusly shifted the testosterone / estrogen ratio in the peri-pubertal rodents from 1.11pg/ng to 0.57pg/ng!

BPA and soy compete for the title of "most potent endocrine disruptor"

Following the bro-scientific "the more the better" type of reasoning, bisphenol A and soy bean extract are two potential candidates for the "testosterone booster of the year"-award. After all both, the organic solvent bisphenol A, as well as the "natural toxin" (sorry, I just had to write that ;-) soy, exert potent (8x) and ueber-potent (100x) effects on the testosterone to estrogen ratio, which is 8.2pg/ng for BPA and 100.1pg/ng for soy!

Note: Neither I, nor the scientists have any clue as to why the results of this study are diametrically opposed to those of previous studies in which extracts from soy products reduced, not increased, testosterone levels in male rodents and monkeys(!), across-the-board (eg. Sharpe. 2002; Cline. 2004) - and that although Sharpe et al. observed an increase in the testosterone producing Leydig cells in their soy-formula fed monkeys. Whether the rats in the study at hand were in a state where similar effects temporarily increase testosterone output until the Leydig cells literally "burn out", or whether other effects were responsible for the temporary increase in testosterone, would have to be elucidated in future studies, the results of which you will obviously read here at the SuppVersity, first ;-)

So, even if we assume that the data is correct and there were no cross-reactions between components in the soy bean extract and the testosterone anti-body test, I would strongly caution against the use of either of this compounds to boost your testosterone levels - I mean what's the use of a wickedly skewed testosterone to estrogen ratio (which in and out of itself will probably mess up your health and can potentially hinder your gains, cf. "Are You Serming Away Your Gains?"), when, at the same time, your testicles turn into dysfunctional balloons?

Intermittent Thoughts on Building Muscle: Estrogen, Friend or Foe of Skeletal Muscle Hypertrophy? Plus: "Hey, Bro! Are You 'SERMing' Away Your Satellite Cells?"

Image 1: Iris Kyle's back is a living testostomy, ah... pardon testimony to the muscle building powers of estrogen ;-)

Although we have identified a hell lot of verified and purported mechanisms by which testosterone, "the Big T" works its muscle building and fat burning magic, the results of the last installments of the Intermittent Thoughts was nevertheless not really satisfying. After discussing how testosterone programs stem cells to become muscle, not fat cells, how it increases the number of  motor neurons and thusly improves the voluntary neuronal activation of skeletal muscle tissue etc., we were still left with the question whether it was actually testosterone of maybe its central or local aromatization or reduction to estrogen or dihydrotestosterone (DHT) which was responsible for the effects. Now, since estrogen is associated with "all things female" and I am a gentleman of the old school, I decided to start with the latter after realizing that it would by no means be possible to tackle both within one installment of the Intermittent Thoughts.

Estrogen makes your muscles weak and your belly fat, right? Not exactly.

Completely contrary to common wisdom, estrogen is by no means the exact counterpart to testosterone. In fact, its potential facilitative if not beneficial or required effects on skeletal muscle hypertrophy are just as undebatable as the negative effects a skewed testosterone to estrogen ratio will have on both the overall health, as well as the physical appearance of men and women.

In an extensive review of the literature, Enns and Tiidus propose the following purported mechanisms by which estrogen may factor in the accrual, repair and maintenance of skeletal muscle tissue (Enns. 2010):

• estrogen as an antioxidant: previous studies have shown that low/high levels of estrogen are associated with decreases / increases in reactive oxygen specimen and markers of inflammation;
   
• estrogen as a membrane stabilizer: while it is probably difficult to distinguish this effect from the aforementioned antioxidant effects of estrogen, it has been shown that by intercalating within membrane phospholipids, estrogen contributes to the stability of the cell membrane;
   
• downstream effects of estrogen receptor binding: dozens of studies have investigated the metabolic effects of estrogen receptor alpha and beta activation; a recent review by Barros and Gustafson (Barros. 2011), for example emphasizes its role in the well-known insulin induced expression of GLUT-4 receptors on the cell-membrane of the muscle; in that, ERα modulates GLUT4 translocation to the cell membrane and thusly stimulates glucose uptake, whereas ERβ is a repressor of GLUT4 expression; in view of what you have learned about the potentially insulin sensitizing effects of testosterone the latter could well depend on the ratio of estrogen to estrone to which the testosterone is converted in the course of central, as well as peripheral aromatization processes; with a high estradial to estrone ratio favoring insulin resistance (estradiol has identical binding affinities for both receptors, while estrone is more or less ERα specific) - a more recent studies by Rüegg et al. does yet suggest that the complete absence of ER is equally detrimental (Ruegg. 2011) and thusly corroborates assessment that our knowledge of the complex endocrine-metabolic interactions is still very limited...

If we summarize these results, it appears that the role of estrogen is not so much to promote skeletal muscle hypertrophy, than to prevent atrophy. This conclusion would be supported by data from Greising et al. who found that the restoration of  normal estrogen levels in overiectomized mice restored the compromised muscle function independent of muscular activity (Greising. 2011). The results of this well-controlled study are corroborated by dozens of human intervention trials (Lowe. 2010) as well as a 2008 analysis of the anti-apoptotic (=countering the self-induced cell death) effects of estrogen signalling in skeletal muscle tissue by Boland (Boland. 2008). All these studies do yet share the same caveat: They analyze the effects of estrogen replacement. And while this may give us a hint at what estrogen does, the results of respective studies are, just as it was the case for testosterone replacement studies, not particularly suitable to make general statements about the effects of estrogen on skeletal muscle hypertrophy.

Estrogen and mitochondrial biogenesis

Image 2: Does estrogen make women better endurance athletes because it increases mitochondrial biogenesis and gears your metabolism towards fatty acid not glucose oxidation? And if that is the case, would men benefit from some more estrogen, as well?

The limitation does not render all the data invalid, but we have to be ware not to overgeneralize results like those, Antonio Zorzona reports in a 2009 article in Applied Physiology, Nutrition and Metabolism (Zorzano. 2009), which would suggest that estrogen plays a very important role in the fusion and remodeling of mitochondria. Zorzona observed that the PGC-1a and PGC-1b expression of which you have probably already read here at the SuppVersity that it is involved in the exercise-induced increase in mitochondrial oxidative capacity, is partly mediated by estrogen-alpha receptor activity. And while it appears questionable that this effect is dose-dependend, meaning more estrogen = more oxidative capacity, it is at least a first indicator that "healthy muscle growth", which obviously includes increases in mitochondrial capacity depends on the presence of "sufficient" (whatever that may be) amounts of estrogen in the blood stream.

A 2010 study from the McMasters University in Ontario, Canada (Maher. 2010), which analyzed vastus lateralis samples of 12 male and 11 female "moderatly avtive" subjects and found that

women have more protein content of the major enzymes involved in long and medium chain fatty acid oxidation which could account for the observed differences in fat oxidation during exercise

would support this hypothesis. After all, this effect could well be related to the "constantly" (de facto estrogen levels obviously vary cyclical ;-) higher amount of the skeletal muscle tissue of the female subjects is exposed to. So, the next time you are huffing and puffing on a jogging tour with your girlfriend, guys, you know that the 3 beers you had the evening before are only part of the explanation for the superior stamina of your significant other ;-)

Feminists please plug your ears: Men and women are different!

If we now remind ourselves of the initially mentioned limitations, the question arises, in how far any of the effects we have discussed so far may be sex-specific.  The aforementioned example of increased fatty acid oxidation in response to estrogen mediated PGC-1a expression, for example, is supported by other researchers, like Tanopolsi (Tanopolski. 2008). Nevertheless, it does yet not bear direct experimental verification: In 2011, Salehzadeh et al. incubated myotubes (muscle fibers) from male and female donors (post-menopausal and age-matched male controls) with either testosterone or 17b-estradiol and found that male and female myotubes respond very differently to "their" respective sex hormones (Salehzadeh. 2011):

Testosterone and E(2) treatment enhanced insulin-stimulated glucose incorporation into glycogen and AKT phosphorylation in myotubes from female donors, highlighting a sex-specific role of sex hormone in glucose metabolism. Testosterone treatment increased palmitate oxidation in myotubes from both female and male donors, while E(2) enhanced palmitate oxidation in myotubes from male donors only. Testosterone-mediated increase in palmitate oxidation was attenuated at the presence of androgen receptor antagonist, which may indicate a role of nuclear steroid receptor in muscle lipid oxidation. [...] E(2) treatment increased pyruvate dehydrogenase kinase 4 mRNA expression in myotubes from female donors. Thus, our data suggest that testosterone or E(2) modulates muscle glucose and lipid metabolism and may play a role in metabolism in a sex-dependent manner.

In the muscle cells of female donors, E(2) [=17b estradiol] acts similarly to testosterone, it increases protein synthesis glycogen storage and protein synthesis (the latter via the well-known AKT pathway). Contrary to what the Zorzona study would suggest, 4-day incubation with estrogen did yet fail to increase the oxidation or fatty acids and geared the energy system of the myotubes from the female donors more towards the glycolytic pathway (thus the increase in pyruvate dehydrogenase). Against that background it seems totally paradoxical that it increased the fatty acid oxidation in the myotubes from the male donors. I mean, don't we all "know" that estrogen makes you fat?

Does estrogen make you fat? Or does fatness make you estrogenic?

Image 3: Beer belly because or despite high estrogen levels? Is that the question or did we get it totally wrong?

Those of you who have followed all the installments of the intermittent thoughts will probably be familiar with the correlation of body fat and estrogen levels in men... now, in view of the aforementioned results from Salehzadeh, et al. it appears that this could be another case where correlation does by no means equal causation. Now that we know that estrogen ramps up skeletal muscle fatty acid oxidation in men, the increase in aromatase activity due to excess body fat of which we have thought only a few minutes ago as a bad thing may well turn out to be a compensatory mechanism by which our bodies are trying to get rid off the excess body fat. Unfortunately, things are not so easy, because increased estrogen levels usually men decreased testosterone, so that you have a catch 21, or even worse, you (assuming you are a male) lose the more potent of the two sex steroid.

Another potential explanation for the lack of "anti-obesogenic" effects of estrogen could simply be its inability to "enter" the fat cells. This is an issue for almost all hormones and a way your body has developed to get water-soluble compounds into a cell is to attach a sulfur molecule to the compound. For estrogen the enzyme that catalyzes this reaction is called estrogen sulfotransferase (EST) and its exceptional high activity in male white adipose tissue has been investigated by several researchers, lately. In August 2011 Wadga et al. report that its expression in pre-adipocytes inhibits their maturation (Wagda. 2011), an observation that should remind you of the anti-adipogenic (i.e. blocking the genesis of new fat cells) of testosterone about which you have learned in the last installment. With testosterone being a "pro-hormone" to estrogen, this suggest that part of this effect could be mediated by local aromatization to estrogen. The increased adipocyte number and size  Misso et al. observed in an aromatase deficient (Misso. 2003), and Ohlson et al. in a estrogen receptor alpha deficient mouse model (Ohlson. 2000) support the hypothesis that, even for men, low estrogen levels could contribute to increased body fat levels.

Estrogen inhibits the maturation of pre-adipocites, ok, but what about "pre-myocytes"?

While it may seem as if I my "intermittent train of thought" has once again lost track of the topic at hand we are actually closing in on what I belief could be one of the most important hypertrophy-specific effects of estrogen: its interaction with satellite cells. That the latter are an important factor in the myogenic equation should not be news to anyone who has been following this series over the past couple of weeks. That the sustaining effects estrogen exerts on these "pre-myocytes" could at least partly explain the drastic difference in sheer muscle mass gains, users of performance enhancing drugs notice from so called "wet" compounds.
Contrary to their "dry" counterparts, these drugs are either susceptible to the aromatase enzyme (mostly to a different degree than testosterone, though) and will consequently be partially converted to estrogen or they do exhibit a certain binding affinity for either the estrogen-alpha or -beta receptor right away (cf. "Beyond Vida" for more info on the binding affinities of various compounds).

The most relevant data (because it does not come from pre- or post-menopausal women, let alone overiectomized rodents) with regard to the beneficial effects of estrogen on skeletal muscle cells comes from a 2005 study by Tidus et al. (Tidus. 2005), who counted the number of satellite cells in a given area of myofibers of red soleus (=slow twitch, type II) and white vastus (=fast twitch, type I) muscle tissue after 90min of intermittent (5min running, 2 min rest) downhill (-13.5°) running on a rodent treadmill at 17m/min (=4.7km/h).

Figure 1: Satellite cell and neutrophil count in normal male rats and male rates who were implanted with a 25mg estrogen pallet before and 74h after 90 min of intermittent downhill running (data adapted from Tidus. 2005)

As the data in figure 1 goes to show the increase in satellite cell count in response to exercise was statistically significantly increased (55% and 11% in the soleus and white vastus, respectively) in the male rats who had been implanted with a 21-day release estrogen pellet (25 mg beta-estradiol) one week before the trial. The number of neutrophils (they are the "first responders" of the immune system), on the other hand was decreased (p < 0.05 only for the soleus). In view of what you have learned in the previous installments of this series (cf. "IGF-1, IL15, Inflammation"), the latter, as well as the aforementioned overall "anti-inflammatory" effect of estrogen appears to be a double-edged sword. In absolute terms the effect is yet negligible and, contrary to the macrophages which we have identified as the "construction workers" who will "install" the satellite cells in the damaged / new muscle tissue, neither the presence nor the activation of neutrophils appears to be required in the actual repair or hypertophy process (Koh. 2009).

Estrogen and satellite cell activation, proliferation and survival

The geeky smart-asses that we are, we will obviously not content ourselves with these observations. I mean, yeah... estrogen is facilitative, but is it necessary, as well? In a way it is quite ironic that it is, once again, a drug that is commonly used by steroid users which provides the answer to this question. The respective study was published in Development and Stem Cells and its title, "Effective fiber hypertrophy in satellite cell-depleted skeletal muscle" would actually suggest that it contradicts everything we have been discussing before. Therefore I deem it necessary to initially point out that the hypertophy response subsequent to synergistic ablation for 2 or 6 weeks was identical for two weeks and slightly reduced after 6 weeks, if we only consider the muscle weight. If, however, we take a closer look at the myofibrial structure, we see the same, in the longer term unsustainable or pathological increases in domain sizes we have discussed in many of the previous installments (e.g. "Growing Beyond Physiological Limits").

Figure 2: Number of myofibers of different sizes in control and mice exposed to synergistic ablation surgery (gastrocnemius and soleus) after two weeks (left) and percent of myofibers with central nuclei (right; data adapted from McCarthy. 2011)

As the data in figure 2 shows, the increase in domain sizes is a way to compensate for the inability to recruit new satellite cells from the quasi non-existant satellite cell pool. At identical muscle weights, the satellite cell depleted mice had thusly on average -66% less myofibers and a -77% decrease in mbryonic myosin expression (not shown in figure 2). This and the low number of central nuclei (figure 1, right), which, as you will probably remember, was a hallmark feature of the huge yet dysfunctional muscle fibers of the myostatin negative mice in the Quaisar study, the results of which I discussed in the Hypertrophy 101, clearly indicate that satellite cells are necessary for healthy and sustained muscle growth.

Hey bro! Are you SERMing away your growth potential?

That estrogen, or I should say the proper activation of the estrogen receptors, is necessary for the maintenance of adequate satellite cell levels, even in the absence of exercise induced muscle damage and consequent satellite cell recruitment, becomes evident, when we take a closer look at the way the scientists depleted the satellite cell pool of their mice (note: while these were female mice, Lepper et al. used the same method in male mice, cf. Lepper. 2011): They used tamoxifen!

Figure 3: Satellite cell count in muscles of mice after treatment with vehicle or 2mg/day of tamoxifen for five consecutive days (left) and images of stained and marked gastrocnemius samples (data and images adapted from McCarthy. 2011)

I suppose the graph on the left of figure 3 would not even have been necessary to identify the profound decrease the intraperitoneal (i.e. into the body cavity) injection of 2mg/day of tamoxifen induced within no more than 5 days (!) in the images of the stained and marked slices on the right.

Assuming that most of you will be aware that tamoxifen (brand name Nolvadex), the hepatoxic effects of which I have addressed in a recent blogpost, is a selective estrogen receptor modulator (SERM), or in other words a synthetic molecule that binds to the estrogen receptor without activating it, it should be obvious that without estrogen, or any other substance that would "dock" to and activate the estrogen receptor healthy, continuous and sustainable muscle growth is impossible.

Take home message: Estrogen is necessary for continuous and sustainable muscle growth

Now, while the take home message that estrogen is in fact a necessary prerequisite of skeletal muscle hypertrophy (at least in the long run), this observation brings the previously raised question in how far the "muscle building effects" of exogenous testosterone, as they were for example observed in healthy young men by Bhasin et al. (Bhasin. 2001) and in community dwelling elderly men on testosterone-replacement therapy by Shinha-Hikim et al. (Shinha-Hikim. 2006) are not, on a cellular level, at least partly mediated by the aromatization of testosterone to estrogen.

And as if things were not already complicated enough, testosterone is a "pro-hormone" not only to estrogen, but also to dihydrotestosterone (DHT), of which bro-science would have it that it is a 10x more potent androgen than the "Big T", itself. As you are probably suspecting by now, we will have to postpone the discussion of the involvement of the manliest of all androgens to the next installment of the Intermittent Thoughts ;-)

Licorice More Estrogenic Than Estradiol: Some of the Flavonoids in Glycyrrhiza Glabra Roots Turn Out to Be Superinductors of the Estrogen-α & -β Receptors

Image 1: In view of the fact that most confectionary licorice contains no more than ~3% of the roots of the licorice plant, I would rather bother about the tricks the ~74g of carbohydrates (on a 100g base) of this treat may play on your insulin levels than about any potential negative effects the consumption of a few or even a whole bunch of these licorice wheels may have on your testosterone levels or overall manliness ;-)

You probably have heard about licorice, the root of Glycyrrhiza glabra, a legume with a slightly sweet taste and one of the ingredient of the eponymous candy being a potent adrenal "revitalizer" that is used and advocated my many naturopathic doctors. If you frequent any of the major health and fitness boards on the Internet, you will yet also be familiar with some of its unwanted side-effects, first and foremost its scientifically validated anti-androgenic (specifically testosterone reducing) effects (Zamansoltani. 2009). While Zamansoltani et al. yet still speculated, whether the reduction in serum testosterone they observed as a result of administration of 150-300mg/kg of licorice extract (HED ~ 40-80mg/kg; 3.2-6.4g for a 80kg human) to male rats still speculated, whether these reduction were the result of "[i]ncreas[es] in T metabolism, down-regulation of androgen receptors or activation of oestrogen [sic!] receptors", a recent study that was published in the Annals of Bioanalytical Chemistry shows that the latter, i.e. the (profound!) activation of both types of estrogen receptors probably was the underlying cause of the emasculation of the licorice treated bucks (Simons. 2011).

Estrogen receptor superinductors were not invented by Dr. Spock

In a pretty meticulous analysis, Rudy Simons et al. found that several fractions of an ethyl acetate extract from licorice root displayed estrogenic activities at either the estrogen-alpha or estrogen-beta receptor that were more pronounced than the ones of the reference "drug", estradiol (E2).

Figure 1: Relative estrogenic activity (in % of estradiol = E2) of 51 fractions that were isolated from an ethyl acetate extract from licorice root (data adapted from Simons. 2011).

If you take a closer look at the 51 fractions the scientists identified by liquid chromatography-massspectrometry and analyzed for their activity by the means of yeast estrogen bioassays, you will recognize that not just one or two, but a whole host of these "fractions", which themselves were complex mixtures of similar compounds, exhibit partly profound estrogenic activity. In that it is particularly noteworthy that the superinduction (activity >E2=100%) was not caused by a post-translational stabilization of the firefly luciferase reporter enzyme, which would have disqualified these results as shortcomings of the yeast essay Simons et al. had used - a effect which has been previously described for genistein, one of the phytoestrogens in soy and soy products.

Figure 2: Relative content and estrogenic activity of individual fractions F1-F5, F6-F21 and F22-F51 from the ethyl acetate extract from licorice root used in the study (calculated based on Simons. 2011).

Of all the fractions, the scientists isolated from the licorice extract, which was supplied by Frutarom US, fraction 41 (F41) with an estrogen-alpha receptor activity of 159.9% at the low (3µg/ml) and 186.9% at the high (10µg/ml) concentrations was by far the 'worst offender'. In view of the fact that we do not know how much of these flavonoids actually make it into the bloodstream, the 103.1, 97.9, 95.5, 74.6, 68.7, 57.2 and 57.3% estrogen-beta activity of fractions F24-F30 at a much lower concentration of 0.3µg/ml is probably more of a concern and most likely the underlying cause of the anti-androgenic effects of licorice, which have also been established in a human study on seven 22-24 year old healthy male subjects by Decio Armanini et al. in 1999 (Armanini. 1999):

Figure 3: Changes in testosterone, androstenedione and 17-hydroxy-progesterone levels (ng/dl) in 7 healthy men upon oral adminstration of 7g of a commercial licorice preparation (data based on Armanini. 1999)

As you can see in figure 3, the 7 g of a commercial preparation of licorice (containing 0.5 g of glycyrrhizic acid) the men in the Amanino study received in the form of tablets (Saila, Bologna, Italy) on a daily basis had an immediate and pretty profound anti-androgenic effect (-44% total testosterone within 2 days!) resulting from the negative feedback of the phytoestrogenic components from Glycyrrhiza glabra. The levels of androstenedione and 17-hydroxy-progesterone on the other hand did not change.

Image 2: Licorice could help with menopause symptoms such as hot flashes, but it has potential corticosteroid-like side effects you should keep an eye on.

Update: Evelyn from CarbSane asked in the comment section whether licorice would not make a good addition to any natural menopause treatment. In fact, she is right that the very estrogenicity of the licorice extracts that is detrimental to men could be of great use for women going through menopause. A cursory search of the databases (how else could it be in view of the fact that you cannot patent licorice) does yet reveal that no one appears to be willing to invest serious money into studies on the effects of licorice / licorice extracts in menopausal women. Nevertheless, there is evidence for estrogen-like bone-building effects (Somjen. 2004) and a -2.4% reduction in the dreaded hot flashes over placebo (Nahidi. 2011).

Moreover, licorice appears to act as an SSRI (selective serotonine reuptake inhibitor) and may thus also help with moodswings and neurotransmitter-imbalances (Ofir. 2003), which can also cause sugar cravings and thusly induce weight gain. If you add to that the growth-inhibitory action the glabridins in licorice exhibit on breast-cancer cells (Tamir. 2000), it may be well worth to try to alleviate menopause symptoms with licorice. In that, it is yet important to know that the glycyrrhetinic acid in licorice has mineralocorticoid-like side effect (i.e. it works like cortisol), which can become problematic especially if licorice is taken as part of one of the typical pharmacological protocols conventional doctors tend to prescribe to their patients (e.g. Inada. 2007). My advice would thus be to carefully monitor your reaction, Ladies ;-)

Against the background of the results of both the initially mentioned rodent study by Zamansoltani et al. (Zamansoltani. 2009), as well as the certainly more relevant data from the 1999 study by Armanini et al. (Armanini. 1999) the 'test-tube' findings by Simons et al. gain a degree of practical significance many of the likewise bio-essay based studies, the manufacturers of purported (!) testosterone boosters like to cite to underline the scientific validity of their products, are lacking... you may want to keep that in mind before you try to counter the unwanted side-effects of a licorice-based "adrenal optimizer" by popping a few servings of the latest and greatest "scientifically proven testosterone booster" ;-)

Estrogen for the Male & Female Physical Culturist? Differential Health Effects in Men and Women. Plus, Estrogen's Role in Satellite Cell Recruitment.

Image 1: Should HE take HER estrogen birth control pills? Or should even she abstain from any exogenous estradiol?
(img free-press-release.com)

Since the earliest research into this topic goes back into the mid 1999s, you will probably have heard about the beneficial effects estrogen has on Alzheimer's (Simpkins. 1997), haven't you? Those headlines along the lines of "Estrogen is the reason why women don't get Alzheimer's as often as men" or "Estrogen protects women from cognitive decline". Now, does that mean that both male and female bodybuilders and fitness athletes should finally give in and stop controlling their estrogen levels in order to get / stay as lean and ripped as possible? Well, a recent study that has been published electronically, ahead of print, in the journal Life Sciences could well shed some light on the question whether for whom of you the down-side to a "no-bloat low estrogen" physique could in fact turn out to be Alzheimer's.

In their study a group of scientists from the Chiang Mai University in Thailand investigated the effects of 50µg/kg subcutaneously injected estrogen for 30 days on the negative impact a "high fat" (I am not tiring of repeating myself that this diet is not only high (60%) in fat and carbohydrates and has 33% more calories on a gram per gram base) had on a group of 40 male and female Wistar rats (Pratchaylsakul. 2011), to test the hypothesis that

the administration of estrogen in both male and female rats can reverse the impairment of
both insulin-induced LTD [in other words: neuronal insulin resistance] in the hippocampus and neuronal insulin signaling caused by a 12-week HF diet consumption.

And as in every good study, W. Pratchayasakul et al. were able to disprove their hypothesis - at least partly. While the desired effects on neuronal insulin signaling did occur in the female mice, similar changes could not be observed in their male peers.

Figure 1: Changes in plasma (pg/ml) and brain (pg/mg) estrogen levels upon administration of 50µg/kg 1 to 40 male and 40 female on different dietary regimens for 30 days (data based on Pratchaylsakul. 2011)

Now, as you can see in the data in figure 1, this effect is not really "sex-specific", in the sense that estrogen would be good for female rat brains and bad for male rat brains, but it is rather the result of an almost paradoxical -14% reduction in brain estrogen levels in the high fat fed female rats who received the 50µg/kg 17-β estradiol. That this differential reaction yet is not the (only) underlying mechanism can yet be seen from the fact that there was a similar, yet statistically non-significant -7% reduction in brain estrogen in the high fat fed male rats, who - this can be seen from the changes in glucose and fatty acid metabolism I plotted in figure 2 - did not benefit to the same extend from supplemental estrogen as their female companions.

Figure 2: Relative improvements in glucose and fatty acid metabolism in rats on a high fat diet after administration of 70µg/kg 17-β estradiol (data calculated based on Pratchaylsakul. 2011)

Nevertheless, even in the male rats, the higher plasma estrogen level (+450%) was not without purportedly beneficial effects on markers of insulin resistance (HOMA-IR, insulin p<0.05 from control) and fatty acid metabolism. Now, before you consider taking some of the estrogen based oral contraceptives of your significant others, I suggest you better look at the price the male rats had to pay for these mediocre improvements in peripheral insulin resistance (cf. figure 3).

Figure 3: Modularory effects of 70µg/kg 17-β estradiol on increases in body weight and visceral fat mass in HFD fed rats compared to rats receiving a normal diet (data calculated based on Pratchaylsakul. 2011)

As you can see the body fat gain of the the male rats literally exploded (+132% over normal diet) when, in addition to the already fattening (+95% over normal diet) high fat diet they also received their daily dose of estrogen. On the contrary, in female rats who turned out to be much more susceptible to high fat diet induced body fat gains, 17-β estradiol reduced the increase in body fatness from +271% in the unsupplemented high-fat group to "only" +125% in the female rats who received 17-β estradiol treatment.

Illustration 1: Damaged muscle tissue will recruit quiescent satellite cells to regenerate the myofiber (img. Scime 2009)

Estrogen? Wait a minute... wasn't there a connection between estrogen, satellite cells and muscular hypertrophy? There are indeed a series of studies which suggest that estrogen does play a major role in the muscular adaption processes to exercise. Estrogen in and out of itself is a strong antioxidant, with properties similar to vitamin E (Subbiah. 1993). It is also known to stabilize cell membranes and thus it is not really surprising that Amelink et al. report a direct inverse relationship between estrogen supplementation and CK release [marker of cellular damage] from muscles of both male and female rats (Amelink. 1990). This may also explain differential effects on muscle damage observerd by Komulainen et al. in a study where male and female rats were exposed to eccentrically biased downhill running and only the male rats suffered from damage to the microarchitecture of the muscle (Komulainen. 1999). Moreover, estrogen increases the expression of HSP-70, one of the heat shock proteins which are expressed as a reaction to acute stressors and "act to attenuate further protein disruption when a subsequent stress such as exercise is again introduced" (Tiidus. 2011).

Now, more importantly, estrogen will also enhance 24 and 72 hours post-exercise muscle satellite cell activation and proliferation (in overiectomized rats, Enns. 2010), which is actually counterintuitive, because estrogen also blocks macrophage infiltration, which has been implicated in satellite cell activation and muscle repair, as well. The beneficial effects on estrogen on satellite cell activation is however mediated directly via estrogen receptors on skeletal muscle (Igbal .2008). As possible underlying mechanisms, Enns et al. list

• insulin-like growth factor-1 (IGF-1) signalling, 
• NO signalling and 
• signalling via the  phospho-inositide-3 kinase/protein kinase B (PI3K/Akt) pathways

All these results have yet to be treated with some caution, because most of the data comes from ovariectomized rats and thus applies only (if at all) to post-menopausal women. This is specifically true for the benefits of "supplemental" exogenous estrogens, of which I doubt that it would promote muscle gains in either men or women (with normal hormone levels).

After all, high estradiol will thus rightly remain among every male bodybuilder's list of chief villains - for the female bodybuilders and figure competitors out there, this could yet be different - after all the beneficial effects especially in terms of neuronal glucose metabolism, which were not be observed in the male rats, could come handy, yet even then, the increase in visceral fat, which was also present in the female rats on a normal diet (+31%!) is a trade-off I am not so sure it would be worth paying.