Talk:Creatine

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Contents

[edit] References?

There are no references for the 'Function' section. The only part that I'm questioning really is that phosphocreatine functions to transport energy from ATP synthesis sites to use sites (why can't ATP just diffuse across the cell itself?) The experiments that established this should be referenced. —Preceding unsigned comment added by Medos2 (talk • contribs) 17:41, 3 March 2008 (UTC)

Zoffoperskof (talk) —Preceding comment was added at 13:17, 2 February 2008 (UTC)

Hi all:

Creatine supplements and supplementation discussions have been moved to the supplements page. Please discuss the biochemical and physiological functions of creatine only on the main creatine page. Thanks! I think this will help separate the two topics -- people interested in supplementation don't really care about GAMT enzymes and biochemists don't care that much about the supplement debate.

Qrater 19:49, 15 February 2007 (UTC)

'Addition of creatine to the vegetarian diet has been shown to improve athletic performance'.

Links to an internet source as 'proof'. However the source pretty much boils down to 'more research needed'.

Revision/removal suggested.

Nerusai

[edit] competition with glutamine for absorbtion

Is there any truth to the claim that creatine competes with glutamine for absorption? -- Sy / (talk) 00:33, 25 March 2007 (UTC)

I guess this is a myth.. [1]
Myth: "Don't take your creatine with protein because protein contains glutamine and glutamine competes with creatine for the same transporter!"
The Real Deal: There's not an ounce of truth to this. Creatine and glutamine have completely different receptors. Creatine transport into skeletal muscle is regulated by the Creatine Transporter7 while glutamine transport into skeletal muscle is regulated by a system known as "System Nm." 8 The only thing these transporters have in common is that they are both sodium-dependent transporters, meaning that they use differences in sodium concentrations across the cell membrane to drive creatine into cells. Apparently somewhere along the line, somebody believed that since glutamine and creatine transporters both shared that characteristic, they must be the same transporter and the myth spread from there. Let the confusion end here: they do not share the same transporter, and taking protein/glutamine with creatine won't decrease creatine uptake into muscle. —Preceding unsigned comment added by Sysy (talk • contribs)
...uhh, I'm relatively sure that by "absorption", they are talking about absorption through the alimentary canal, like after you eat them. Leondegrance —Preceding unsigned comment added by Leondegrance (talk • contribs) 02:10, 11 September 2007 (UTC)

Dear Contributors:

[edit] Long further reading section

I move this here, I doubt if these references were used to write the article, but they may be useful to expand it.

  • Burke DG, Chilibeck PD, Parise G, Tarnopolsky MA, Candow DG. (2003). "Effect of alpha-lipoic acid combined with creatine monohydrate on human skeletal muscle creatine and phosphagen concentration.". Int J Sport Nutr Exerc Metab. Sep (13): 294-302. PMID 14669930. .
  • Dangott B, Schultz E, Mozdziak PE. (2000). "Dietary creatine monohydrate supplementation increases satellite cell mitotic activity during compensatory hypertrophy". International Journal of Sports Medicine 2000 Jan (21(1):): 13-6. PMID 10683092. .
  • Hespel P, Op't Eijnde B, Van Leemputte M, Urso B, Greenhaff PL, Labarque V, Dymarkowski S, Van Hecke P, Richter EA. (2001). "Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans". J Physiol. 2001 Oct 15 (536(Pt 2)): 625-33. PMID 11600695. .
  • Hultman E, Soderlund K, Timmons JA, et al. (1996). "Muscle creatine loading in men.". J Appl Physiol (81): 232-237. PMID 8828669. .
  • Juhn MS. (2003). "Popular sports supplements and ergogenic aids". Sports Med. 33 (2): 921-39. PMID 12974658. 
  • Powers ME et al. (2003). "Creatine Supplementation Increases Total Body Water Without Altering Fluid Distribution". Journal of Athletic Training 38 (1): 44-50. PMID 12937471. .
  • Rae C, Digney AL, McEwan SR, Bates TC. (2003). "Oral creatine monohydrate supplementation improves cognitive performance; a placebo-controlled, double-blind cross-over trial.". Proceedings of the Royal Society of London - Biological Sciences 270 (1529): 2147-2150. PMID 14561278. .
  • Robinson TM et al. (2000). "Dietary creatine supplementation does not affect some haematological indices, or indices of muscle damage and hepatic and renal function". British Journal of Sports Medicine 34: 284-288. PMID 10953902. .
  • Schroeder C et al. (2001). "The effects of creatine dietary supplementation on anterior compartment pressure in the lower leg during rest and following exercise". Clin J Sport Med. 11 (2): 87-95. PMID 11403120. 

Wallimann T, Wyss M, Brdiczka D, Nicolay K, Eppenberger HM. Intracellular compartmentation, structure and function of creatine kinase isoenzymes in tissues with high and fluctuating energy demands: the 'phosphocreatine circuit' for cellular energy homeostasis. Biochem J. 1992 Jan 1;281 ( Pt 1):21-40. Review.

Shin JB, Streijger F, Beynon A, Peters T, Gadzala L, McMillen D, Bystrom C, Van der Zee CE, Wallimann T, Gillespie PG. Hair Bundles Are Specialized for ATP Delivery via Creatine Kinase. Neuron. 2007 Feb 1;53(3):371-86.

T. Wallimann, M. Wyss, D. Brdiczka, K. Nicolay, and H.M. Eppenberger. Intracellular compartmentation, structure and function of creatine kinase isoenzymes: the "phospho-creatine circuit" for cellular energy homeostasis. Biochem. J. 281: 21-40 (1992). (Comprehensive review with the PCr-circuit model)

T. Wallimann, and W. Hemmer. Creatine kinase in non-muscle tissues and cells. Mol. Cell Biochem. 133/134: 193-220 (1994)

--Dirk Beetstra T C 12:34, 20 November 2007 (UTC)

[edit] Creatine

I am confused as to why it says that it may cause kidney damage, and then says that it is secreted in a benign form. Does benign not mean harmless? 24.65.87.238 (talk) 03:58, 21 March 2008 (UTC)

its awsome —Preceding unsigned comment added by 69.151.179.70 (talk) 01:03, 4 April 2008 (UTC)

[edit] Controversy

The use of creatine has been controversial. Whether it should be controversial is another issue. As time goes by with further proof of effectiveness and no indications of problems, these older claims become less and less relevant. At some point it may make sense to reword this section to say something like "initially there were claims that creatine use was not effective and possibly dangerous, but these have not been borne out", or something along those lines. For now, I've restored the deleted statements and their supporting references. --Mmm (talk) 16:44, 19 April 2008 (UTC)

Werty26262626 (if that's really your name ;-), you have not responded to my comments above. You seem to feel that because you disagree with the sources (an MD and a journalist) it is appropriate to remove links to their comments. I respectfully disagree. I added those references because the statements about creatine use being controversial were marked by someone else as needing references, and the references I supplied do indeed show that there are credible sources making those statements. In other words, there has been controversy over creatine use. These references document that fact. Or are you trying to claim that there has not been controversy? If so, can you provide documentation of the lack of controversy? --Mmm (talk) 22:55, 26 April 2008 (UTC)

Hi, Mmm! As I've said before, my problem is not with the statements themselves, but with the references provided(and just to make myself clear, the previous editing summary, was in response to Edward321's)! I mean, of course I want everyone to know about the facts and controversy surrounding the use of creatine! But to be specific here, my problem with the M.D.'s article, resides in the fact that it doesn't cite any bibliographical references at its end. Also, the fact that he doesn't make any clear distinction between the supplements mentioned below the main article and the forbidden substances he also mentions there(steroids and h.g.h.), seems a bit weird. But in the end, he did make it kind of clear (in the main creatine article) that the point is that «absence of proof, isn't proof of absence»!... So I must admit, that I may have exaggerated a bit, when I removed that article, since it served to prove the main point(controversy), and for that I appologize to everyone! But reference number 3, that one I can't agree with! In this reference, she(Amber Davis) makes statements along the lines of: «its drug like physical addictiveness»; and: «the unfair advantage it gives»(almost every strength and speed athlete uses it anyway, not to mention the fact that creatine doesn't produce such unbelievable results, besides being legal and, for all we know, proven safe). She then goes on by adding: «If an athlete loads on creatine continually, then it is possible and probable that the body will eventually quit making it on its own» (I thought only steroids were known to do that? But then what about glutamine? If we eat it, say, by consuming eggs, does that mean that our body will stop making it on its own? Amber Davis seems to ignore the fact, that after the loading phase, one's only supposed to use 3 to 6 gr. a day...Hardly enough to hinder our body's own creatine production. Besides the fact that cycling, although not proven to be necessary, is recommended!); and that due to the absence of naturally ocurring creatine: «a disastrous effects could occur, even death»(her spelling). She also states that creatine increases the chances of severe injury(logic:an athlete is on creatine and he injures himself severely, ergo creatine did it) and that there is: «an increase of urinary creatine excretion» (geez, could that be creatinine?). She finally states that creatine will, or at least may cause heart, kidney and liver failure/disease! So, to sum it all up, creatine use, according to A.D., will make your body cease endogenous creatine production, may cause death (via the previously mentioned mechanism), causes addiction, increases the risk of severe muscle injury and may also cause heart, liver and kidney(possible on people with pre-existing kidney problems, but not proven) failure. And all I ask is: where's the proof of these(statms.)? Where are the verifiable bibliographical references? Where's the science? I'd say that Amber Davis is pulling these statements straight out of her ass! Furthermore, I doubt that she's even a real journalist, and if she is, then shame on her! Bear in mind, that this article was taken from a site, where there are 13 and 15 y.o. kids talking about their experience with whey and stuff like that, which already tells us that this isn't some sort of scientific journal/site, or anything of that sort! Also, I've never even heard/seen that type of statement made in any published study about creatine, and I've asked this to my Exercise Physiology teacher, and all he told me, was that there probably was more research done on creatine, than on any other supplement before it, and that all of the data has proven it(creat.) to be safe and effective(if used properly)! So you can't just go around saying this and that about creatine or anything else, unless you have viable and reliable studies to support whichever claims you're making. Besides, for all it's worth, just like creatine might end up being SCIENTIFICALLY proven dangerous farther along the road(or 100% safe, we don't know it yet); with time and proper research; that is also valid for t.v., mobile phones, the internet, microwave ovens, hell even many pharmaceutical drugs and the very food we eat(even though most of these are considered fairly safe)! But for now, it is important to keep an open mind, and most of all, a fair judgement, and not to start being alarmist(like Amber Davis has been). And since for the time being, none of A.D.'s statements seem to be scientifically proven, and appear to be based on nothing more than assumptions and poor logic, they should thus, be permanently removed from wikipedia. Because we all have an obligation towards ourselves and each other, of providing nothing more than research proven, unbiased sources of information, something that can only be accomplished through the elimination of all fallacious content from wikipedia! Unless the objective is to manifest a personal view, which should be done elsewhere, and especially, without doing so under the guise of real science/journalism. Truth, is of the utmost importance! And on a final note, I believe that the substances we all should try to eradicate from sports, are steroids and h.g.h.(and such). And this can only be accomplished by promoting safe and effective training, healthy and balanced nutrition and, why not, a sound supplementation regimen... This is something towards which moderate creatine monohydrate(the only independently researched form of creatine) use might as well contribute!! Oh, and always remember, that there are a lot of bad journalists and M.D.'s out there(paid by the drug companies, supplement companies, and such. Some are just stupid!), so we have to be extra careful when choosing an article from the web, for it might not be what it seems at first sight(being from a REAL journalist or M.D., is not enough)! I hope we agree on this, and that all «no. 3 references» remain outside of wikipedia forever, not because they tell you something you don't want to hear/know about, but because they're not based on science and telling the unbiased truth! --Werty26262626 (talk), real wikipedia user name, no sock puppet, 27.04.2008.