Epigallocatechin Gallate (EGCG), Capsaicins, Piperine & Carnitine: Rather a Health Than a Fat Loss Stack?

That's not what the ultimate weight loss diet looks like. The pill remains a supplement, i.e. something to supplement (and support) your dietary and exercise efforts, nothing more, but - as long as you pick the right one for your type and goal - also nothing less (photo ehow.com)

Let me first remind you of the fact that something that works in your obese neighbor does not necessarily work as effectively in someone like yourself, a devoted physical culturist who is only a couple of steps away from the six pack he has always been dreaming of. Let me also emphasize the fact that taking the supplement alone, i.e without the -600kcal reduction in energy intake all of the 86 overweight subjects (healthy males and females aged 25–45 years, with a body mass index greater than 25 kg/m² less than 35 kg/m²) had to stick to, there probably wouldn't have been any weight loss at all. And lastly, let me also formulate the hypothesis that the various health benefits, such as the increases in insulin sensitivity, the improvements in the leptin/adiponectin ratio or the decreasing LDL levels would probably have been less pronounced without the game-changing reduction in energy intake.

Simple Truth: The right diet, not the right supplements is the key factor in losing body fat

Apropos reduction in energy intake, one of the most underrated but practically highly relevant beneficial effects the administration of the epigallocatechin gallate (EGCG from green tea), capsaicins, piperine, L-carnitine and a few minor ingredients (see figure 1, left) probably brought about certainly were the psychological benefits, such as the 3.3 pts decrease on the Beck depression inventory (BDI-II), since the ability and will to adhere to a diet - whether this may be for 8 weeks as in the study at hand or (preferably) for life - obviously hinges on the question: "Can you stick to it?"

Figure 1: Energy content (primary axis in kcal) and macronutrient composition (secondary axis in g) and ingredients of the of the weight loss supplement (Rondanelli. 2012)

That said, the diet composition in figure 1 (left) certainly raises another question: "Would it even be wise to adhere to this diet for longer than 8 weeks?" I mean it stands out of question that living on a caloric deficit for the rest of your life is not an option. If you look a the macronutrient composition of the diet, on the other hand, my personal  prognosis is that this program will not yield long-term success. Not because it's high in carbs, but because it is too low in protein and lacks an exercise component - typical mainstream dieting = typical mainstream failure - with or without "bioactive food ingredients" (Rondanelli. 2012).

Fat loss or anti-diabesity stack? That is the question!

The combination of a lack of exercise stimuli and a relatively low dietary protein intake (certainly below the threshold limit of 10g+ of EAA per meal) is probably also the main reason for the slight loss in lean muscle tissue, a phenomenon  - and that's interesting, although the difference did not reach statistical significance - occured only in the supplemented  group.

Figure 2: Changes in body composition (left) and selected markers of glucose management and fatty acid metabolism, adipokine expression and inflammation (Rondelli. 2012)

Now, there are obviously dozens of potential reasons for the minimal muscle loss in the supplement group. In my humble opinion the most likely explanation does yet relate to the very same increase in resting energy expenditure (+120.6kcal/day) that's (alongside the metabolic improvements, cf. figure 2, left) behind the additional 600g of body fat, the subjects in the supplement group shed in the course of the 8-week dietary intervention.

"600g in 8 weeks? Are you kiddin' me?"

Yep, you read me right, 600grams is all the supplement yielded as far as additional fat loss is concerned. That, plus the fact that neither this, nor any of the differences in between the changes in anthropometric data reached significance does tell you something about the actual weight loss effects even obese and insulin resistant subjects can expect from taking an epigallocatechin gallate (EGCG from green tea), capsaicins, piperine and L-carnitine based dietary supplement.

What? That's pathetic? Well, it would be if these changes were not accompanied by way more important and statistically significant different effects on the insulin sensitivity of the 41 overweight subjects in the supplement group who completed the study.

As far as the inhibition of diet induced weight gain and insulin resistance are concerned, there is no synergism of green tea and the L. plantarum, a probiotic. Green tea does the job, the bacteria stand by and watch in awe (read more)

Bottom line: As I've pointed out numerous times before. There are a different types of weight loss adjuvants, with one of the most general, if you will "fundamental" distinctions between (a) those weight loss supplements that have a more or less pronounced direct effect on the energy balance (=carb/fat blocker, beta-agonists, thyroid mimetics, appetite suppressants etc.) and (b) their healthier cousins that promote your weight loss efforts by ironing out acquired metabolic obstacles, such as leptin and insulin resistance. And though you could certainly make a point that green tea exhibits some features of both categories, the overall stack used in this study belongs to the second category and it's efficacy is therefore going to drop the healthier (=less inflamed, insulin & leptin sensitive) you are, when you start dieting.

You may want to keep that, as well as the (un-)fortunate truth that there simply is no "fat burner pill" on the market that will do the allegedly hard dieting and exercising for you, in mind, whenever you pass by the storeboard with the virtual or real shelves of a supplement store and are tempted to invest 50$ or so into yet another "next generation fat burner"... without having a diet and workout plan and the will to stick to it, you can just as well save the 50$.

References:

• Rondanelli M, Opizzi A, Perna S, Faliva M, Solerte SB, Fioravanti M, Klersy C, Edda C, Maddalena P, Luciano S, Paola C, Emanuela C, Claudia S, Donini LM. Improvement in insulin resistance and favourable changes in plasma inflammatory adipokines after weight loss associated with two months' consumption of a combination of bioactive food ingredients in overweight subjects. Endocrine. 2012 Dec 28. [Epub ahead of print]

L-Carnitine Works! Yet, Maybe More Subtly Than Thought: 1.2-5g L-Carnitine Increase Expression of Genes Implicated in Fatty Acid Oxidation, Glucose & Lipid Metabolism.

Image 1: This is you... well, not exactly. It's rather an animal model of human carnitine metabolis ;-)

As a faithful student of the SuppVersity it stands out of question that you have read my masterpiece *rofl* on the "Purported Ergogenics" in the "Amino Acids for Super Humans Series". You will thusly be familiar with the inconsistency of the mostly disappointing results of randomized, placebo-controlled trials. Whether it was for fat-loss, for increases in exercise performance or whatever else the producers of respective supplements promise would happen, when you buy and take their oftentimes profoundly underdosed supplements, in the absence of pathological (or severe dietary) carnitine deficiency the observed effects, if there were any, were negligible.

A soon to be published paper by Janin Keller and other researchers from the Institute of Animal Nutrition and Nutrition Psychology at the Justus-Liebig-University, in Gießen, the Institute of Agricultural and Nutritional Sciences at the Martin-Luther-University, in Halle-Wittenberg, and the Hans-Knöll-Institute, Research Group Systems Biology/Bioinformatic, in Jena (all in Germany, btw.), does now shed some light onto the more subtle, epigenetic effects of l-carnitine supplementation (Keller. 2011).

Image 2: The calculation of human equivalent doses is a constant (unreliable) pain in my ass - either you don't have the adequate conversion ratio or you do not know how much an animal eats. weighs etc...

Note: While my calculation (see below) indicates that the equivalent dose of the dietary enrichment used in the study should be ~4-5g, Keller et al. use a different method to calculate dose equivalents that is based on the ~500g of feed the pigs consumed per day. According to their calculation the daily dose of l-carnitine on a per kg body weight base for the piglets (final body weight: 17kg) was 15mg/kg body weight l-carnitine. If we now take a look at our conversion table (cf. table 1), where this specific type of big obviously is not listed, we probably have to divide that by 1.1 to get the Human Equivalent Dose - but since this is for "Mini pigs", we will just leave it with 15mg/kg and would thus have a dose of only 1.2g for an 80kg human being.

Keller et al. fed a group of 16 male crossbred pigs (body weight at study begin: ~10kg) a standardized diet with a naturally occurring amount of <5mg/kg carnitine. Half of the pigs, did receive additional 500mg/kg carnitine in their feed. In view of the fact that this effectively centuplicated (x100) the carnitine content of the diet, and considering the fact that the average human dietary carnitine intake ranges from ~47mg in men to ~30mg in women (Lennon. 1986), this would translate into an additional dose of roughly 4-5g of supplemental l-carnitine per day for humans. If you buy your carnitine in bulk (currently ~5$ per 100g) mimicking the supplement regimen used in the study would cost you about 25cents a day... but I guess before you do that you will rightly want to know what the potential benefits would be.

Figure 1: Liver free and total l-carnitine levels (in nmol/g) in growing piglets after 21-days of normal or carnitine supplemented feed (data adapted from Keller. 2011)

As you can see in figure 1 the liver of the animals literally squirreled the l-carnitine away (this could also be the reason, why most of the previously cited studies saw only transient increases in serum l-carnitine levels and almost no increases in muscular carnitine stores). An increase of +915% in free and +937% in total liver l-carnitine content is - I probably don't have to mention that - more than significant and was not without consequences... consequences of which scientists probably would not have even thought about 10 or even 20 years ago - epigenetic changes of which Keller et al. write:

we observed that 563 genes were differentially expressed by L-carnitine. This shows that supplemental L-carnitine influences gene expression in the liver of piglets and indicates that at least some of the biological effects of L-carnitine are mediated by altering gene transcription. [...] Gene term enrichment analysis revealed that the most frequent biological processes associated with L- carnitine supplementation were dealing with metabolic processes. This was not surprising considering that the main function of L-carnitine is to stimulate energy metabolism by acting as shuttling molecule for long-chain fatty acids which also enhances the metabolic flux of glucose through the glycolytic chain. This was also confirmed by clustering analysis showing that 6 out of the 10 top-ranked clusters were dealing with metabolic processes. Representative genes from one of these clusters dealing with metabolic processes (carboxylic acid metabolic process, oxoacid metabolic process, organic acid metabolic process) encoded proteins or enzymes involved in cellular fatty acid uptake (SLC27A6, solute carrier family 27/fatty acid transporter, member 6), fatty acid activation (ACSL3, Long-chain-fatty-acid-CoA ligase 3) and fatty acid β-oxidation (ACADSB, Acyl-CoA dehydrogenase, short/branched chain specific), and most of these genes including SLC27A6, ACSL3 and ACADSB were found to be significantly up-regulated by L-carnitine supplementation.

Moreover, the researchers found that a whole host of genes (e.g. GLUT8, GCK and GPD1 more than 4x elevated) related to glucose metabolism (glucose transport, conversion of glucose into glucose 6-phosphate, and glycolysis, and hexose biosynthetic processes, like gluconeogenesis) and triglyceride metabolic and triglyceride biosynthetic processes were elevated, as well. Taken together this lead the scientists to conclude that the epigenetic changes that were induced by 21 days of (relatively) high-dose dietary l-carnitine supplementation suggest that the "conditionally essential" amino acid l-carnitine

1. ... exerts its "well-known stimulatory effect [...] on fatty acid β-oxidation" at least partly by stimulating the transcription of genes involved in "cellular fatty acid uptake, fatty acid activation and β-oxidation"
2. ... has profound beneficial effects on glucose metabolism and utilization, which are mediated "not only by [a genetically triggered] stimulation of glycolysis but also suppression of gluconeogenesis in the liver", and
3. ... triggers genetic modifications which lead to an "inhibition of glycerolipid biosynthesis and stimulation of lipoprotein secretion and fatty acid catabolism", which contribute to its overall beneficial effects on lipid metabolism.

Now that you have all the facts, I'll leave it up to you to decide whether those "hidden" genetic changes are worth the 0.25$ (or 0.06$ if you use the 1.2g dose, cf. red box above) you would have to pay for your share of supplemental l-carnitine per day... and by the way: don't ask me if whatever other form of carnitine will do just as well, better or worse. This is a question only a separate study could answer!

Combinations that Work: HMB & Isometric Training for Lean Mass, Creatine & Powerlifting for Leaning Out and Carnitine & Bodybuilding for Powerlifting?

Image 1: Jacek Spychala - I must admit, I don't know if he was one of the subjects, but 38 of his colleagues from the Polish National Powerlifting Team were (powerlifting.pl)

As an athlete and even as a regular fitness enthusiast, you got to chose your training and supplementation modalities according to your professional or personal goals (in fact, the failure to do so is, in my mind, one of the main causes why so many trainees do not get the desired results at the gym). A very recent study from the Department of Combat Sports and Weightlifting at the Józef Pilsudski University School of Physical Education (I wish every University had such a department ;-) in Warsaw, Poland, sheds some light onto combinations which work, and combinations which don't... and trust me you will be surprised by the results of Dr. Marek Kruszewski's controlled intervention study (Kruszewski. 2011).

Kruszewski recruited recruited a total of 170 (! that alone is noteworthy !) subjects who participated in a three-tier placebo-controlled study on the effects dietary supplementation of l-carnitine, creatine and HMB combined with different modes of strength training (bodybuilding type circuit training, powerlifting and isometric training) had on muscle strength, lifting performance and body composition (for a graphical overview of the study design see figure 1).

Figure 1: Graphical illustration of the three tiers (l-carnitine, creatine, HMB), general information and detailed information on the exact exercise protocol of the isometric workout of the HMB group

Not only the sheer size of the study with active and placebo groups of ~30 previously untrained subjects, each, in the l-carnitine and HMB tier of the study are impressive, the participation of 38 powerlifters from the Polish National Team (cf. video of Daniel Grabowski, with a 2254lbs total) is, as well. If each group had received all three of the supplements subsequently and body composition had not been measured with an expensive but still not 100% accurate body impedance device, this study would have been the equivalent of the egg-laying-wool-milk-sow of the Natural Rythmicity for Maximum Fat & Minimal Muscle Loss episode of the Intermittent Thoughts, but I guess we cannot have it all ;-)

2g HMB + isometric training for lean muscle gains!

Image 2: HMB is getting
cheaper, lately

I thought, I'd give the most "exotic" training variety (isometric training) the advantage and tell you about the effects 2g of HMB per day (4 servings of 500mg; one with breakfast, one before, one after the workout and one in the evening; for 5 weeks = 20 training sessions) had on the strength performance and body composition of 69 previously untrained, strength trainees -  not only to raise the awareness that isometric contractions could be a valuable addition to everyones regime (something my friend Rob Regish also advocates in his Blueprint), but also because the effects observed in this tier of the study were, as Kruszewski points out, "[t]he most distinctive and desirable" ones:

Although this type of supplementation [HMB] was used in the group of subjects who trained using the isometric method, regarded as a training system not associated with increases in lean body mass (LBM), the obtained results indicate that HMB may also affect LBM. In view of the fact that LBM involves mainly muscles containing about 70% water, the demonstrated significant elevation of LBM accompanied by the reduced water content in the bodies of the examined competitors is difficult to explain.

Now, I've got you listening my iron-friends, don't I? Increased lean mass (+1.31kg), decreased (as the author points out, later) "presumably extracellular" water - sounds like it was coming from a competitive bodybuilder's "dry dreams", doesn't it? Well, the one thing that would be missing now, is a way to get rid of the fat - but wait, weren't there other supplements in the study, as well?

10g Creatine (+10g dextrose) + powerlifting for fat loss!

Image 3: Creatine monohydrate
for fat loss? That's a surprise.

Yes, there were, and believe it or not, not l-carnitine and circuit training, but creatine and powerlifting will shed the fat - even in elite level powerlifters! By continuing their regular (pyramid style, cf. figure 1) powerlifting training, the 16 power lifters from the Polish National Team, who received the 20g/day creatine + dextrose combination did not only improve their powerlifting performance by a statistically significant +15.6kg over the placebo group, they also and, as Kruszewski points out, "surprisingly" lost a significant amount of body fat in the course of the 20 training sessions they completed within the 5 week study period:

[...] the present results indicate that supplementation with this compound [creatine] led to a significant reduction in the fat content and increase in the water content of the organisms of powerlifters from the Polish National Team.

In view of the results, the author observed in the last group, the one which did a bodybuilding-type circuit training that was supplemented with 900mg of l-carnitine l-tartrate per day (cf. figure 1), I find it pretty amusing that according to Kruszwski the "effect of creatine may be much more far-reaching than that indicated in the manufacturers’ leaflets", which is something, he certainly would not say of l-carnitine.

900mg l-carnitine l-tartrate + "bodybuilding-type" circuit training for powerlifting? 

Image 4: L-carnitine alone will not transform your physique like this magic mirror - no matter what the advertisement leaflet in the latest muscle mag says ;-)

The results in the l-carnitine supplemented group (3x300mg l-carnitine l-tartrate) were mixed. While the previously untrained subjects obviously gained strength in the course of the 15 workouts they performed in the 5 week study period, there were huge intergroup differences - meaning that a few subjects appeared to benefit from carnitine, while the majority didn't. Moreover, fat loss or beneficial changes of body composition, which is what l-carnitine is marketed for, were completely absent in the l-carnitine group. And while the training intensity was pretty low (although the trainees had to perform the 3rd of their three training circles to complete failure) this does not really surprise me, as the "fat burning" effect of oral carnitine supplementation has been debunked by more than a dozen well-designed studies, so that you better follow Kruszewski's advice and "treat advertisements of this compound [l-carnitine] with reserve" ;-) He goes on to explain that...

[...i]t is possible that individuals with inherited or acquired L-carnitine deficiency manifested by increased deposition of fat in the body may benefit from such supplementation and improve their body composition by consuming appropriate amounts of this substance accompanied by proper (predominantly aerobic) exercising. However, additional L-carnitine supplementation in individuals with normal production and concentration of this substance in the body is superfluous.

On the other hand, Kruszewski admits that despite the absence of significant improvements in muscle torque, the powerlifting performance of the subjects in the l-carnitine group increased statistically significantly more than the one in the placebo group (+13.7kg) which is ...

surprising in view of the fact that such an effect [increase in powerlifting performance] of L-carnitine has very rarely been reported and emphasized.

He goes on to suggest that these improvements may be related to l-carnitines impact "on the general physical fitness of the organism". Yet, whatever the reasons may be - out of this triumvirate, l-carnitine would certainly be the least effective addition to your regimen - whatever your goals may be.

Isometric training and HMB supplementation, on the other hand, emerge as as surprise winner. With statistically significant (+17.7kg) increases in power-lifting performance, significant increases in muscle torque, and a +1,31kg increase in body mass (predominantly lean muscle) that was accompanied by a likewise significant reduction in extracellular water, it may be a good idea to take advantage of the falling HMB prices (buy in bulk!) and to incorporate some isometric exercises into your workout regimen ... what do you say?

Body Fat Modulation with Corn Oil & L-Carnitine: What You Can Learn From Your Schnitzel

Its quite remarkable that, primates aside, swine are among the best models of human metabolism. So, even if you do not feel piggy at all, the fact that pigs just as humans are omnivores, makes them a much better model for metabolic disease than rodents. It is thus not too unrealistic to assume that we can learn something about ourselves from the results of a very recent study published in the Journal of Animal Science (Apple. 2011).

Figure 1: American Pork Cuts; quality is determined by corn-oil and carnitine intake of the swine.
What lessons can you learn from our pink relatives?

Investigating the effects of l-carnitine supplementation on the quality characteristics of fresh pork bellies from pigs fed three levels of corn oil, J.K. Apple and his co-workers observed a linear trend towards decreased belly-firmness with increasing amounts of corn oil (0, 2 or 4%) in the diet. If you look at the average American, his/her high corn oil consumption and their respective (pot-)bellies, this should not surprise you. All aesthetic considerations aside, those feisty pot-bellies are nothing but the outward sign of metabolic derangements that - without appropriate lifestyle interventions - have their owners suffer from diabetes, high blood pressure, chronic inflammation, and all the other players in the (eventually) deadly "game" of metabolic syndrome.

[...] belly firmness decreased linearly (P < 0.001) with increasing dietary OIL, but there was no (P ≥ 0.137) effect of CARN on any belly firmness measure.

Now, did the touted fat-burner l-carnitine prevent these effects? No, it didn't. Yet, what it did do is it increased the amount of saturated (SFA) and mono-unsaturated (MUFA) fatty acids and decreased the amount of polyunsaturated fatty acids (PUFA) in the belly tissue:

Dietary CARN increased (P < 0.05) the proportion of total SFA in the intermuscular fat layer, increased (P < 0.05) the proportion of total MUFA in the primary and secondary lean layers, and decreased (P < 0.05) the proportion of total PUFA in the intermuscular fat and secondary lean layers of pork bellies.

In view of the finding that increasing the amount of corn oil in the diet tended to increase the PUFA content of the belly tissue, while depositing the highly oxidative polyunsaturated fatty acids preferentially in fat and not lean layers, one must acknowledge that L-carnitine, despite not being able to prevent the outwardly visible (and touchable) negative effects of a diet high in omega-6 rich corn oil, was yet able to modulate the effects of excess PUFAs on intra-tissue body fat composition.

Against the background of the recent changes in the scientifically accepted perspective on the previously vilified saturated fatty acids and possible beneficial effects on cell stability and inflammation the significance of these results goes beyond profane insights into the management of pork quality and solidify the foundation of my previous recommendation to avoid omega-6 instead of increasing the overall PUFA load by additional omega-3 supplementation. What's new, however, is the role l-carnitine supplementation may play in your efforts to get rid of overly high tissue levels of omega-6, since the reduced storage in fat tissue and the increased storage in muscle could be able to (a) decrease inflammation of the fat tissue and, at the same time, (b) increase oxidation of PUFAs in exercised muscle tissue. Yet, without appropriate dietary changes and the incorporation of regular exercise sessions into your  new, healthier lifestyle all carnitine in the world won't help you, if you insist on eating too many breaded and fried schnitzel with French fries and a boatload of mayonnaise and ketchup.

Energy Drinks Increase Resting Metabolic Rate, But Do Not Influence Energy Expenditure During Exercise

Ever wondered, whether the drink that was once rumored to contain "taurine from bull sperm" and similar fashionable "energy drinks" are of any use? Well, a recent study (Nienhuesser. 2011) coming from an international team of scientists showed that the consumption of each and every of the three energy drinks used in this study lead to a statistically significant increase in resting metabolic rate (RMR).

[...] in a randomly assigned cross-over design, the subjects consumed 473 ml of one of three commercially available energy drinks or a placebo and then RMR and RER [respiratory exchange ratio; i.e. a measure of the relative amount of fat/carbs that is used as fuel] were measured 1 hour later.  The subjects then engaged in 15 minutes of treadmill exercise at 50% of V02max, during which RER and oxygen consumption (VO2) were measured. RMR was not changed by placebo, but increased (P<0.05, means ± se) above baseline by 10 ± 2.5%, 15.0 ± 2.9%, and 15.3 ± 2.9%, following Energy Drink One, Energy Drink Two, and Energy Drink Three (respectively) [...]

In view of the stimulating effect, some of the ingredients (cf. Table 1) of these chemical containing beverages exhibit, these results do not come as a surprise.

Table 1: Listing of ingredients according to Nienhuesser. 2011

What may be surprising, however, is that the study results suggest that - at least from a "calorie expenditure" point of view - the consumption of an energy drink before exercise appears to be less effective than drinking it after exercise or at your desk at the office...

L-Carnitine Works! At Least if it's L-Carnitine L-Tartrate.

Initially, carnitine was considered the super-supplement for both, the athlete seeking the ergogenic edge, as well as for the obese trying to shed unhealthy body fat. Surprisingly, however, study after study showed no to little effect on exercise performance and/or fat loss. Ultimately, it became clear that, even at very high doses, only very little of the orally delivered l-carnitine actually makes it to the muscle. Consequently, its effects on performance and body composition where negligible. Now, a very recent study by Wall et. al. (Wall. 2011) found that adding a transporter, in this case l-tartrate, to the molecule does not only help to increase muscle carnitine levels, it eventually produces exactly those effects on exercise performance and substrate metabolism one would have expected from l-carnitine supplementation in the first place.

The scientists had their 14 healthy male volunteers ingest either 80 g of CHO (Control) or 2 g of L-carnitine L-tartrate and 80 g of CHO (Carnitine) twice daily for 24 weeks in a randomised, double blind manner. Other than in previous studies with plain l-carnitine (minus the l-tartrate) there was a significant increase of muscle carnitine content with all the downstream metabolic benefits on exercise performance one would expect:

Muscle TC increased from basal by 21% in Carnitine (P<0.05), and was unchanged in Control. At 50% VO2max, the Carnitine group utilised 55% less muscle glycogen compared to Control (P<0.05) and 31% less pyruvate dehydrogenase complex activation (PDCa) compared to before supplementation (P<0.05). Conversely, at 80% VO2max, muscle PDCa was 38% higher (P<0.05), acetylcarnitine content showed a trend to be 16% greater (P<0.10), muscle lactate content was 44% lower (P<0.05) and the muscle PCr/ATP ratio was better maintained (P<0.05) in Carnitine compared to Control. The Carnitine group increased work output 11% from baseline in the performance trial, while Control showed no change.

So, after all, it was not the wrong the substance previous investigations used, but rather the wrong form - l-carnitine l-tartrate - though expensive - is the way to go to burn fat and increase athletic performance. If you do not want to buy it in bulk, I suggest you at least buy a product like MAN Sports Body Octane, where you actually know how much (here 1g) of the carnitine you're getting per serving.

L-Carnitine Changes Gene Transcription in Muscle - After all, it Works!

L-Carnitine has long been among my favorites of expensive supplements with ostensibly conclusive scientific background which are pretty worthless in practice. Now, a new study by Keller et al. (Keller. 2010) found that L-Carnitine supplementation in piglets had a distinct effect on gene expression in skeletal muscle:

Transcript profiling revealed 211 genes to be differentially expressed in muscle by carnitine supplementation. The identified genes were mainly involved in molecular processes such as cytoskeletal protein binding, insulin-like growth factor (IGF) binding, transcription factor activity, and insulin receptor binding. Identified genes with the molecular function transcription factor activity encoded primarily transcription factors, most of which were down-regulated by carnitine, including pro-apoptotic transcription factors such as proto-oncogene c-fos, proto-oncogene c-jun and activating transcription factor 3. Furthermore, atrophy-related genes such as atrogin-1, MuRF1, and DRE1 were significantly down-regulated by carnitine. IGF signalling and insulin signalling were identified as significantly up-regulated regulatory pathways in the carnitine group.Conclusion: Carnitine may have beneficial effects on skeletal muscle mass through stimulating the anabolic IGF-1 pathway and suppressing pro-apoptotic and atrophy-related genes, which are involved in apoptosis of muscle fibers and proteolysis of muscle proteins, respectively.

For athletes and gymrats the part in bold could be of particular interest, because after all, improved IGF and insulin signalling should translate into enhanced muscle growth.Unfortunately, the scientists from the Justus-Liebig-Universität in Gießen, Germany, do not mention the amount of carnitine the piglets were fed, so we cannot tell, whether the effect may be due to "L-Carnitine-overfeeding" or if the usual amounts of supplemental carnitine (1-5g) would suffice to produce similar results in pig and/or man.

4g L-Carnitine Per Day do not Increase Muscle Carnitine and/or Exercise Performance

Only 2 days ago, you read at the SuppVersity about L-Carnitine being a costly, but ineffective ingredient in many weight loss supplements. Today's news is about a study on the effect of 14-day l-carnitine supplementation (4g/day) on muscle and blood carnitine fractions, and muscle and blood lactate concentrations, during high-intensity sprint cycling exercise. The results observed in 8 subjects were unambiguous:

L-carnitine supplementation had no significant effect on muscle carnitine content and thus could not alter lactate accumulation during exercise.

The increase of plasma carnitine, on the other hand, is insufficient to bring about the ergogenic effects carnitine supplements are advertised for. So if you can't get it into the cell, you could as well dump it into the toilette - or better just don't buy it ;-)

No Effect of L-Carnitine on Fat Loss or Body Composition in Obese Women

After last weeks "bad" news on L-Cartinine L-Tartrate the supplement industry, which is still promoting various kinds of l-carnitines as fat loss aids, just received another beating. In a double-blind randomized placebo study Villani et al. (Villani. 2010) investigated the effects of 8 weeks of 2g/day l-carnitine supplementation on body composition, resting energy expenditure (REE) and substrate utilization of 18 premenopausal  women walking @60-70% of their maximum heart rate 4x a week:

Figure 1: Chemical structure of
L-Carnitine (HMBD v2.5)

For the subjects who completed the study (15 P, 13 L-C), no significant changes in mean total body mass (TBM), fat mass FM, and resting lipid utilization occurred over time, nor were there any significant differences between groups for any variable. Conversely REE increased significantly for all subjects, but no between group differences existed. Five of the L-C group experienced nausea or diarrhea and consequently did not complete the study. Eight weeks of L-C ingestion and walking did not significantly alter the TBM or FM of overweight women, thereby casting doubt on the efficacy of L-C supplementation for weight loss.

To sum this up: Do not take l-carnitine if it is not your wallet that is supposed to lose a few pounds ;-)