Retrospectacle: A Neuroscience Blog

Energy drinks are ubiquitous these days. They have become a multi-billion dollar industry….even Nelly has a drink called “Pimp Juice” and Lil John has “Crunk” energy drink. Advertised to improve stamina, energy, and mental power….what’s not to love? By far the most popular of these drinks is Red Bull, which is a Austrian/Thai fizzy apple-flavored jolt. But what is really in these energy drinks, or more specifically, what is the reason that Red Bull “gives you wings?” And, can it be good for you? (More below the fold…)

The ingredients of Red Bull (per 250 mL serving) include:
27g sugar
1000mg taurine
600mg glucuronolactone
80mg caffeine
B-complex vitamins

Sugar isn’t great for you, but is a relatively benign ingredient. 27 grams is quite a bit less than the 39 grams that are in a 12oz Coke. Either one will substantially raise your glucose level, though. This is a moot point, of course, if you prefer the Sugar-Free Red Bull.

As for the caffeine content, which most people assume is where the real boost effect comes from, its less than a 8oz cup of coffee, but 2x as much as a can of Coke. Nothing really out of the ordinary, but won’t help your caffeine addiction either. FYI, the LD50 for caffeine (this means the amount of caffeine it requires to kill 50% of an animal test group) is about 10g (or 10,000 mg). You’d have to drink 125 Red Bulls to get that much caffeine. Given how much they cost, that seems quite unlikely.

Glucuronolactone is a natural chemical produced in the body as a byproduct of glucose metabolism by the liver. This compound received some notoriety, as it was used by the US government during Vietnam to improve soldiers’ sense of well-being and to stave off depression. It is a precursor to taurine.

Taurine (above) is also called 2-aminoethanesulfonic acid, and is so named due to its preliminary discovery in ox bile. It has since been located in a variety of animals and plants, and is quite abundant in sushi and seafood. Taurine is an amine, but not an animo acid as it is not part of the universal genetic code. It has a documented biological roles as an ingredient in bile salts (to lend a negative charge), and has been implicated in inhibitory neurotransmission, LTP in the hippocampus and striatum, fat regulation, calcium homeostasis, and membrane stabilization. The evidence for the ‘implicated roles’ is weak still; much more research needs to be done to fully understand taurine’s role.

There is some evidence that taurine can treat hypertension. Several rat models of hypertension have been used to suggest that dietary taurine supplementation can alleviate high blood pressure. These beneficial effects were also demonstrated in humans suffering from hypertension; supplements as little as 6g/day for as little as 7 days resulted in a significant decrease in the blood pressure of these patients.

And quite interestingly, a recent study by a nutritional biology group at Japan’s National Institute of Health and Nutrition shows that taurine supplements given to mice on a high-fat diet reduced their overall weight. This jives well with the ongoing observations that societies with fish-based diets suffer less obesity than those that primarily eat meat (taurine is not abundant in the edible parts of mammals). Previous experiments have shown that increased intake of taurine can reduce high blood pressure and cholesterol levels. This group decided to compare mice on a high fat or high carb diet, and found that the high-fat mice became obese and had reduced levels of endogenous taurine in their blood as well as reduced levels of enzymes required for synthesizing taurine in adipose tissue (fat stores).

The team noted that the decrease in the production of taurine occurred 14 days or more after the high-fat diet was started, leading them to speculate that the reduction resulted from diet-induced changes in the adipocytes. “This creates a vicious cycle promoting obesity,” says Tsuboyama-Kasaoka [a researcher in the study].

However, here’s where it gets interesting: when the team gave the high-fat mice a 3mg/gram (of a mouse’s weight) dose of taurine, they didn’t become obese. They measured energy expenditure, and concluded that the mice burned off the fat because of higher at-rest energy consumption. The study was published in Endocrinology here. The bad news, in a way, is that humans would have to consume about 150-250 grams of taurine per day to meet an equivalent dose, although I suspect that a much lower dose may be as effective. Mice have extremely fast metabolisms, and cycle chemicals out of their bodies at a much faster rate than humans.

One more interesting thing: in the presence of B6 vitamins (included in the ingredients of Red Bull), taurine is also synthesized into methionine and cysteine. Methionine is used by the body to form creatine, which important in maintaining and building muscle mass. In addition, it has been suggested that methionine can prevent bacteria from sticking to urinary tract cells, reducing bladder and urinary tract infections similar to cranberry juice. In addition, one study in rats suggests that methionine protects the liver against the damaging effects of acetaminophen poisoning. (Neuvonen PJ, Tokola O, Toivonen ML, et al. Methionine in paracetamol tablets, a tool to reduce paracetamol toxicity. Int J Clin Pharmacol Ther Toxicol. 1985;23:497-500.)

Take home message? Red Bull’s “wings” seem to be a largely benign mixture of the stimulants caffiene and sugar (although no more than regular soda or coffee), as well as surprisingly encouraging (if not 100% substantiated) effects from taurine. While it seems doubtful that it truly enhances mental ability or stamina any more than soda or coffee might, the truly intriguing benefits (reduced obesity and hyertension) of taurine supplementation aren’t even part of Red Bull’s advertising schema. Perhaps as more research is published supporting these results, taurine may well be a supplement that our doctors encourage us to take.

Comments

#1 Abel Pharmboy
June 17, 2006

Great post, professor. I have a very deep interest in this area for other reasons. The dose issue you describe for taurine is very common in the energy and dietary supplement world.

Glucuronolactone is potentially a drug interaction timebomb. It inhibits beta-glucuronidase in the gut, enhancing the excretion of glucuronide conjugates – good for “detoxification.” However, as just one example, oral contraceptives rely on the fractional enterohepatic recycling of estrogen and progestin conjugates, thereby furthering their duration of action. Glucuronolactone has the potential to enhance the excretion of OCs and compromise their contraceptive efficacy.
#2 drb
June 17, 2006

Nice post, but I am confused by your claim regarding the synthesis and function of creatine. In humans, creatine is formed by the enzymatic conjugation of glycine with arginine, which is then methylated in a subsequent step (disorders of creatine synthesis are well-documented). The function of creatine is not in maintaining and building muscle mass, but rather as a reservoir of phosphate for transfer to energy-containing compounds including ADP, and seems to be of most importance in the CNS (low brain creatine levels, as a result of impaired synthesis or a nonfunctional transport/uptake system, are extremely deleterious, with features ranging from absent speech to intractable seizures and severe mental retardation).
#3 Orac
June 17, 2006

Another problem is, Red Bull tastes truly disgusting. The one time I tried it, I couldn’t even finish the small can. I had to go and chug a Coke in a futile attempt to get rid of the taste. I can’t believe people actually like this stuff. Or maybe they don’t but think it’s giving them “energy.”
#4 drb
June 17, 2006

Perhaps I spoke too soon; if you meant that methionine is the methyl donor (via S-adenosylmethionine)in the last step of creatine synthesis (methylation of gunaidinoacetate), then of course you are right, though SAM is a methyl donor for many biochemical reactions, not just this one. However, I would hypothesize that the rate of creatine synthesis is independent of the blood methionine concentration unless it approached an extremely low level. I guess what I’m saying is, if you want to build up your tissue creatine stores, there are easier and cheaper means to do so than drinking Red Bull.
#5 Ed Darrell
June 17, 2006

“Jibe.” I think you meant “jibe,” when you wrote “jive.” It’s a nit, I know, but I see such errors as part of the long slide to creationism.
#6 drb
June 17, 2006

Oops, one last thing. You state “…in the presence of B6 vitamins (included in the ingredients of Red Bull), taurine is also synthesized into methionine and cysteine”. Really? Under typical physiologic conditions, taurine is synthesized FROM methionine via cysteine in a multistep process, not vice versa. Of course, the B6 is irrelevant as it is a cofactor for the cystathionine beta-synthase reaction, which catalyzes the interconversion of homocysteine and cystathionine (with Km favoring cystathionine production). Can you cite any reference demonstrating a significant increase in blood methionine levels as a result of taurine supplementation? It seems like quite an uphill synthetic endeavor in a multistep biochemical process that strongly favors the opposite reaction, but I am happy to be reeducated if I am incorrect.
#7 Whimsical Monkey
June 17, 2006

“Several rat models of hypertension have been used to prove that dietary taurine supplementation can alleviate high blood pressure.” I don’t think that you can have a model prove anything. “Show” or “suggest” but not “prove”.
#8 Carl Manaster
June 17, 2006

While we’re nitpicking – it’s “tract,” not “track.” I don’t consider the issue quite as important as Ed does; just FYI.
#9 Zombie
June 17, 2006

Isn’t taurine the substance cats are unable to synthesize on their own, making them obligate carnivores?
#10 Farrold
June 17, 2006

True, taurine isn’t an amino acid, but this isn’t because it isn’t genetically encoded. Many amino acids are not. Instead, it’s not an amino acid because it isn’t, in fact, an amino acid
#11 Austin
June 17, 2006

This is a topic of great interest to me, thanks for the great post. If anyone has links to additional information about the chemistry of energy drinks, it would be greatly appreciated.
#12 Anonymous reader
June 17, 2006

Austin, I understand that a comprehensive review article is in press with the open-access journal, Medscape General Medicine, in their Clinical Nutrition & Obesity section. Registration is free but required. MedGenMed is a peer-reviewed, rapid publication eJournal edited by Dr. George Lundberg, former Editor-in-Chief of JAMA. I’ll drop a line to Ms. Batts when the review is available, likely in August or September.
#13 Shelley
June 17, 2006

I have changed “tract” and “prove.” And I certainly meant “jive.” Thanks though, really. :/

Abel, thanks as ever, and for the info on contraceptive interactions.

db, thanks for all the info on methionine, etc. Yes, I meant methionine was a methyl donor, and yes there are certainly cheaper ways to build muscle than drinking RB.

And I’d love to read that review, whenever its out, send it my way.
#14 Shelley
June 17, 2006

And one more thing. I’m a graduate student, and I don’t know everything. I write about topics of interest to me, some that are not in my area of expertise. But, I do my best to find out relavent, useful, and correct info. I appreciate it when people use their knowledge to supplement posts. It’s great! But if you are just leaving a comment about a misspelling or misuse of a word, I rather you didn’t. I write how I talk, which is casual. Grammar nazis, go elsewhere.
#15 natural cynic
June 17, 2006

Creatine acts to stimulate an increase in muscle mass two ways. Acute creatine supplementation [5-25 g/day are often taken by bodybuilders and other strength athletes] will cause muscle creatine to increase and osmotically draw water into the muscle. Side effect: dehydration and a need to increase fluid. Over a longer period of time, increased creatine concentration in the muscle will increase the amount of intermittent, high-intensity work the muscle can accomplish and therefore will increase the hypertrophy stimulus. [bigger muscles suck up more creatine which suck up more water ...]. source
#16 drb
June 17, 2006

To say that muscle mass is being increased by increasing the water content osmotically is a pretty unconvincing argument, as one commonly understands the term to suggest increased muscle tissue. In fact, the reference you quote specifically refutes this claim; ie, it is false to claim that muscle mass is being increased when in fact it is only water. As for creatine increasing the amount of high intensity work that muscle is able to do, this is only meaningful if you actually DO the work. Couch potatoes who imbibe heroic quantities of creatine supplements but do no exercise are wasting their time and money. Their muscle mass will not increase. From the standpoint of physiology, injected human growth hormone is a much more efficient agent for promoting accretion of actual muscle mass.
#17 George Atkinson
June 18, 2006

Watch for that shifting base! The claim that “27 grams [of sugar in a 250g serve of Red Bull] is quite a bit less than the 39 grams that are in a 12oz Coke” offers a misleading comparison when one considers that 39 grams in a 340g Coke has the same concentration as 27.5 grams in a 250g Coke. I have to suspect the claim of caffeine content as “2x as much as a can of Coke” misleads in the same way.
#18 Shelley Batts
June 18, 2006

Yep, if you want to consider it that way. And that’s why I included the serving size. You (or at least I) don’t drink 2 Red Bull instead of drinking one Coke. Its a choice of ONE or (one of) the other. Therefore it isn’t misleading in the slighest to observe that one serving of X has less than one serving of Y. And I’m not making any “claims.” I’m reading straight off the back of the can.
#19 Jeremy
June 18, 2006

Ed Darrell,

Do you not have anything better to do?
#20 me2i1
June 19, 2006

One more nitpick is that the LD50 is usually expressed as mg/kg of body mass, so you have to scale by the mass of the animal. As you mentioned, rats have a faster metabolism than humans, so it’s not quite linear.
#21 Andy
June 19, 2006

What about the positive effects on blood pressure?

When combining an anti-hypertonic drug with caffeine, you will end up with the same or even elevated levels of blood pressure. Considering people with metabolic syndrome Red Bull probably will make matters worse. Maybe the placebo component (“wings”) has the most positive effect.

In Austria, Red Bull also is quite popular (Mostly among young people mixing gettin ga ‘Wodka Bull’).
#22 Shelley Batts
June 19, 2006

I don’t think that question has yet been investigated, but its a good one.

As for the effects of mixing energy drinks with alcohol, that has been investigated. See:

http://tinyurl.com/y5p9kk

and

http://tinyurl.com/u8etv

In a nutshell, although it makes you feel less drunk (less perception of headache, dizziness, etc), you aren’t, and you don’t perform any better on motor tasks or visual reaction tasks.
#23 Redleg
June 23, 2006

Excellent article, wish I was knowledgeable enough to contribute. Instead I have a question, ancillary to the point of the article and regarding creatine. I have watched the debate over its ability to “build” mass, and whether the mass can be maintained after supplementation ceases, for a while now. If Shelley were to address drb’s initial question that would be great, but I would be interested in a supported bottom line answer to the question of whether creatine can help to build sustainable mass post-supplementation, or if it is simply stealing lactic acid’s place in regenerating muscles? Does the body make its own creatine and how is it generally used? The athletes in my field, and my coach in particular, seems to think that 5grams of creatine a day is necessary on the days we fight just to recover, indicating its ordained biological tendency is to sustain the body’s muscles and retard fatigue. Indeed, I notice a general fatigue when I do not supplement. I would like to add just some mass, but am not interested in hormonal supplementation (I’m angry enough as it is . Generally the athletes in my field now easily recognize when someone is “creatine stacking” and the practice is frowned upon, but if used in between fights to build or add a few pounds of lean muscle mass (3 – 5 pounds in my case) it would certainly be less deleterious than the subsequently recommended hormonal supplementation.
Many thanks, and sorry for hijacking a bit here.
I kept waiting for the “bad” on drinking red bull, but now, nasty tasting or not, red bull it is. I also intend to look into Taurine supplements.
This article is a service, Shelly, thanks.
#24 Shelley Batts
June 24, 2006

Hi Redleg, glad you liked the post. Be careful w/ the taurine supplements, as sometimes more isn’t *always* better. As for the creatine, the honest answer is I don’t know. But be on the lookout here cause i’m doing some looking into the matter and I’ll likely post on creatine later in the week. I’m pretty interested to know about this myself.
#25 Redleg
June 26, 2006

Many thanks, Shelley, I’ll be a regular from here on out. And yes, I’ve already made the switch to Red Bulls (but duly noted on Taurine supps). Omega-3s have been a regular for sometime now. All the best
#26 Alone
June 29, 2006

This is from memory, no time to look it up now, so confirm for yourselves:

Campral (acamprosate) is a medication for reducing cravings for alcohol (that it does’t work very well is besides the point). It is structurally similar to taurine (both have SO3-CH2-CH2-); both similar to GABA.

And there is a not inconsequential body of literature showing a link between low taurine and diabetes (especially gestational) and Cushing’s disease. This is probably via inhibition of effects of homcysteine– note taurine can be cardioprotective in hyperhomocysteinemic patients. (It does this also by blocking free radical production.) Patients with beta-thalassemia (Mediterraneans/Arabs)have a correlation between decreased essential amino acids (especially taurine, also meth, leu, val, etc) and impaired growth.

Anyway, Red Bull is delicious.
#27 becky
July 2, 2006

I like your website alot…its lots of fun…
#28 amy davies
August 8, 2006

nice article, tho the benefits of redbull seem to be flowing out, and sound extremely similar to the jargon the redbull marketing team give when questioned about the safety of their product…. As with taurine giving higher at rest rate, this maybe good for wait loss but so are amphetamines in diet pills!! The body needs that time to rest and as the heart only has a limited number of beats in a persons lifetime, by drinking redbull you are effectively shortening your life. Redbull isnt a mix of single products, it is the speed like effect of mixing all the products and how they work together. We have facts about each single ingredient in the product but no tests have been performed on the effects of using all the compounds together.
Prolonged use of a product that mimicks amphetamines effects, leads to not just physical problems but mental problems. Using a product to keep you awake when tired has bad effects. People are overlooking the fact of caffeine induced pshycosis as well as the effects of sleep deprevation. using an energy drink in the day will lead to a poor nights sleep, then the product is used again the next day, this can occur until the mind breaks. The physical effects of using high sugar drinks can lead to diabetes……fact. The use of sugarfree redbull can lead to cancer, the amount of carcinogenic sweetners needed to mimic the sweetsness of redbull is dangerously high, the sugarfree version can also give you mouth ulcers….is this safe/normal for a drink? cigarettes yes. is redbull the new marlboro? my final point is; would you give your children redbull??
#29 Jay townsend
August 8, 2006

Good points Amy, though not really scientifically backed up! Has anyone ever tested the effects of redbull on rats/humans? I would love to here anything? cigarrettes/redbull? And NO I WOULD NOT GIVE IT TO MY CHILDREN!!! Or drink the crap
#30 Shelley Batts
August 8, 2006

Amy, thanks for commenting. Although its not true that “the heart has a limited number of beats” (thats just a urban legend). And if products that kept you awake at night were terrible, then no one would drink caffiene, period. When in fact, there have been documented many good benefits to low level caffiene intake (search on pubmed!). also, there is absolutely no evidence that has ever suggested a causal line between red bull and cancer, so thats a worrisome claim. But if you are worried about aspartame (the rats that got cancer were given massive, massive doses by the way) just don’t drink the sugar free kind. I think it tastes bad anyway. I’m not recommending people drink it everyday, by any means. I just reported on what was in the medical literature. And what I happened to find wasn’t so negative.
#31 amy davies
August 8, 2006

ok, good return to my comments. I am interested in the combined effects of the ingredients. You have stated articles about the effects and benefits of individual ingredients but it is the interraction between them on the body that will give the real truth. (People who work for redbull say it isnt the individual ingredients, it is the way they interract that gives the effects). glucuronolactone is a mood enhancer and yes in the vietnamese war it was given to soldiers, who subsequently got brain tumours. It enhancers up, but after you finish with the effects of redbull it enhancers the down, like a comedown off amphetamines. redbull does not help to build body mass it actually decreases it.
#32 Shelley Batts
August 8, 2006

Its hard to say what the combined effects are. No one has done studies on Coke, types of wine and beers, cocktails, etc in this way either. And every one of those drinks also has active ingredients that may be harmful. So Red Bull isn’t being held to a lesser, or higher, standard. In reality, we’re all part of one huge experiment testing these effects. The FDA has declared it safe, but no medical studies specifically on the effect of red bull have been done (except the one I mentioned about not feeling as drunk). This largely has to do with medical necessity. Money could be better spent testing a cure for x disease than testing whether drink 900 red bulls makes you sick. The court of public opinion and health has yet to complain of bad effects past those of regular caffinated drinks–therefore I suppose caffiene-sensitive people shouldn’t drink it. What I COULD find was evidence detailing the effects of individual ingredients. It may not be as accurate as the whole, but i’m not claiming to be a doctor either. Just looking at what I can, whats available in the public record and not anecdotal evidence.
#33 amy davies
August 8, 2006

you state these facts, that sound very similar to a redbull marketeers. suggesting that the drink is safe and that you would have to drink many cans for any adverse health effects. drinking with alcohol can dangerously dehydrate you and that wouldnt be 125 cans. though you state this evidence and are basically saying that redbull might be benficial…… I do not suggest wasting money on testing by medical facilities but i do want someone, even redbull to pay for an unbiased (if there is one!!) report on the combined effects. your statements are in favour of redbull, though if you look up the ingredients you will also find adverse effects but you do not state them. You are right a caffeine sensitive person should not drink a caffeine drink. As for the FDA, i would not trust everything they pass.
#34 Catriona
August 9, 2006

Hello Shelley and others,
What an interesting discussion!
I have a bit of a tangential question regarding the production of the taurine used in red bull and other energy drinks, does anybody know how it is made? – I realise it is predominantly found in animals and fish, but for the use in energy drinks, is it animal derived or otherwise?
Regarding the comment “glucuronolactone is a mood enhancer and yes in the vietnamese war it was given to soldiers, who subsequently got brain tumours”.
This is another urban legend, which Snopes (the website devoted to finding the origin of such legends) found was untrue – though I am not sure how reliable this is…
Here is the website for those interested:
http://www.snopes.com/medical/potables/redbull.asp
#35 Mark Jerraford
August 9, 2006

try this page
repositories.cdlib.org/cgi/viewcontent.cgi?article=1096&context=uclabiolchem/nutritionbytes
#36 Harry Damer
August 9, 2006

The official imported Canadian Red Bull is a caffeinated version of Thai Krating Daeng (Red Bull). Until late 2004, its sale was prohibited in Canada. Now a can must carry a warning label that says: �Caution: Contains caffeine. Not recommended for children, pregnant or breast-feeding women, caffeine sensitive persons or to be mixed with alcohol. Do not consume more than 500 ml per day.� However, no such warning label is present on cans sold in the U.S. nor in the U.K
#37 Shelley Batts
August 9, 2006

Interesting, Harry. Do other caffinated drinks contain the same warnings? Red bull has less than a 8oz cup of coffee, so does coffee come w. a warning?

Catriona, thanks for pointing out the urban legend. That sounded pretty fishy to me as well.
#38 harry damer
September 17, 2006

Hi shelley. The amount of caffeine is not comparable, when cold the body absorbs more caffeine at a higher rate, so the amounts in coffee and a can of redbull cannot be compared on the amount in the total volume of liquid, it is the rate at which it is absorbed into the bloodstream and the amount present in blood. I feel for one country to put a warning on and not others is a little concerning regarding the safety of a product passed by different Food Standards Agencies.
#39 Danyelle
September 23, 2006

how many mg of red bull would you have to take to become effective?
thank you
Danyelle
#40 CHRISTIAN
November 15, 2006

FYI, the LD50 for caffeine (this means the amount of caffeine it requires to kill 50% of an animal test group) is about 10g (or 10,000 mg).

SPEECHLESS.
#41 rae
January 4, 2007

you mentioned that taurine can be found in plants as well. would you happen to know if that is the type (taurine from plants) used in red bull? i am a hindu and i think it is atrocious that in india it is not advertised (if so ) that extracts from ox (related to the cow family) is used. as you may or may not know the cow is sacred in our religion and we do not eat anythign associated with beef. iw ould much perfer if you could please spare the time to e-mail me your answer. i would greatly appreciate it. thanks!!!!
#42 Nick
April 22, 2007

According to the Red Bull website, the taurine is synthetic. The site also claims that the drink is acceptable under Halal, Kosher, and vegan dietary rules.
#43 alistair
July 16, 2007

hello, recently i began using redbull before soccer in place of a starbucks as a look-see and found that i liked the “legs” i got as a result. i`m 46 and appreciate all the help i can get on a friday night.

i did some casual research and discovered that one of the ingredients, taurine, is available over the counter in canada, so i bought 500mg caps.

other than the three goals i got on friday i have noticed a dramatic feeling of calmness and overall well-being since beginning this course. and vivid early morning dream recall.

i realise this is all non-scientific stuff, my area of study is in divinity so i`m not qualified in any way to make statements in science, but i appreciate the discussion.

regarding the creatine issue, it was my understanding that the way it worked was by allowing atp to remain present in nerve tissue longer in the cycle of repititions of an exercise, thereby allowing the muscles to work harder (contraction.) in the gym than before.
#44 m�zik dinle
November 17, 2008

ok, good return to my comments. I am interested in the combined effects of the ingredients. You have stated articles about the effects and benefits of individual ingredients but it is the interraction between them on the body that will give the real truth. (People who work for redbull say it isnt the individual ingredients, it is the way they interract that gives the effects). glucuronolactone is a mood enhancer and yes in the vietnamese war it was given to soldiers, who subsequently got brain tumours. It enhancers up, but after you finish with the effects of redbull it enhancers the down, like a comedown off amphetamines. redbull does not help to build body mass it actually decreases it.
#45 Alexandra
November 26, 2008

I had 2 seizures because of red bull. Stay off that stuff. If you have questions please feel free to e-mail me.

Alex
#46 General Chemistry
October 21, 2010

A lot of these compounds are also present in 5 Hour Energy, minus the taurine, which is maybe why I don’t feel like crap after taking one of those….any thoughts?
#47 houston nutrition
March 23, 2011

Perhaps I spoke too soon; if you meant that methionine is the methyl donor (via S-adenosylmethionine)in the last step of creatine synthesis (methylation of gunaidinoacetate), then of course you are right, though SAM is a methyl donor for many biochemical reactions, not just this one. However, I would hypothesize that the rate of creatine synthesis is independent of the blood methionine concentration unless it approached an extremely low level. I guess what I’m saying is, if you want to build up your tissue creatine stores, there are easier and cheaper means to do so than drinking Red Bull.
#48 houston nutrition
March 23, 2011

Many thanks, Shelley, I’ll be a regular from here on out. And yes, I’ve already made the switch to Red Bulls (but duly noted on Taurine supps). Omega-3s have been a regular for sometime now. All the best