Factors Influencing Creatine Absorption

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savagebeast

New Member
I've been looking at some information about creatine and various factors that can improve creatine absorption. Here are the main ones I've found. Please feel free to comment on any of them.

1. Dextrose - the idea here is that taking dextrose (or some other high GI carbohydrate) along with creatine will create an insulin spike, increasing creatine uptake into muscle cells

2. Alpha-Lipoic Acid - not sure how, but it's supposedly proven to improve creatine absorption

3. Micronized Creatine - smaller particles means more surface area, better mixing, less stomach irritation, and better absorption

First of all, how significant are each of these factors?

Second, from what I understand the whole point of taking creatine is to keep your muscles saturated with creatine. To me, this seems to imply that there is a limit to how much creatine your muscles can store. If there is indeed a limit to creatine retention, then what is the big deal about maximizing absorption? All you would need to do is absorb enough creatine to keep your stores full, right?
 
Most of the studies done researching creatine and it's effects use just creatine and water, and most of the findings seemed to show that mixing with water is sufficient. I wouldn't worry about it too much, but taking with some carbs is definitely not going to hurt anything.
 
Creatine allows your muscle cells to store more water which in turn allows the cells to take in more of what they need (for want of a better explanation).

Yes, creatine levels hit a max level (maximum saturation) but you want as much of the creatine absorbed as possible. Talking 5g doesn't mean 5g (100%) gets to your muscles.

Yes, the micronised stuff is easier to mix (less gritty).

I wouldn't make a big deal of it. Just buy the stuff, load and lift
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I've heard ppl say you shouldn't take creatine with anything acidic . . .soft drink, citrus juice etc. . . .except it seems to me that your stomach is highly acidic, so what's the deal...?
 
[b said:
Quote[/b] (Jester @ April 19 2005,8:33)]I've heard ppl say you shouldn't take creatine with anything acidic . . .soft drink, citrus juice etc. . . .except it seems to me that your stomach is highly acidic, so what's the deal...?
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A couple of studies indicated that co-ingesting creatine with large amounts of caffeine or acidic drinks may negate some of the performance enhancing effects of creatine supplementation. For this reason, some have suggested that creatine should not be taken with caffeine or acidic drinks. However, many studies on creatine that reported benefits mixed creatine in hot coffee or tea to help dissolve the creatine. Additionally, muscle creatine content was increased in these studies despite the presence of caffeine. From what I have read creatine is not degraded into creatinine through the digestive processes despite very low pH levels and since the PH (acid level) of coffee, grape juice, and orange juice is less than that found in the gastrointestinal tract I doubt it makes a whole lot of difference. One study I read shows it isn't degraded into creatinine until after the first six hours of digestion. Therefore, IMHO I doubt that mixing creatine in fruit juice or caffeinated drinks would degrade it unless you mix it in them and let it sit for a while.
 
[b said:
Quote[/b] (baby a @ April 13 2005,4:28)]but taking with some carbs is definitely not going to hurt anything.
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It actually helps quite a bit. Nearly all of dietary creatine is absorbed by the small intestine into the blood. The muscle then absorbs creatine from the blood as needed. The absorption of creatine in the muscle is influenced by sodium and insulin. Sodium serves as a co-transporter of creatine into muscle tissue and muscle creatine uptake is enhanced when insulin levels are high. Creatine just flowing through the blood doesn't do anything (it just gets flushed) it needs to be absorbed into the muscle tissue to be effective. It is recommended to ingest creatine with a glucose drink or a carbohydrate/protein drink to get the most effective use from it.
 
[b said:
Quote[/b] ]From what I have read creatine is not degraded into creatinine through the digestive processes despite very low pH levels and since the PH (acid level) of coffee, grape juice, and orange juice is less than that found in the gastrointestinal tract I doubt it makes a whole lot of difference. One study I read shows it isn't degraded into creatinine until after the first six hours of digestion. Therefore, IMHO I doubt that mixing creatine in fruit juice or caffeinated drinks would degrade it unless you mix it in them and let it sit for a while.
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That's exactly my thinking; regardless of whether you take creatine with coffee, apple juice, orange juice, soft drink or water, your stomach has a much lower pH than any of these, so if you're mixing then swallowing it right away there won't be time for the mixer to 'degrade' the creatine (or any logic as to why the stomach wouldn't do so anyway).

The reasoning I've heard ppl don't take creatine and caffeine together is b/c creatine causes water retention in the muscles, where as caffeine is a diuretic, so there won't be as much water retention if you're taking it.
 
Dan, how significant is the role of sodium in creatine uptake? Should I be taking my creatine with a sports drink containing both dextrose and sodium, such as Gatorade made from the powder mix (I believe pre-bottled Gatorade doesn't contain any/as much dextrose, plus it's more expensive)? Or would it be fine to just take it with dextrose?
 
[b said:
Quote[/b] (savagebeast @ April 19 2005,8:17)]Dan, how significant is the role of sodium in creatine uptake?  Should I be taking my creatine with a sports drink containing both dextrose and sodium, such as Gatorade made from the powder mix (I believe pre-bottled Gatorade doesn't contain any/as much dextrose, plus it's more expensive)?  Or would it be fine to just take it with dextrose?
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The transporter mechanism is a sodium ion (Na+) dependant transporter, I haven't seen anything that improves creatine transport with ingestion of sodium. So I wouldn't go around eating more salt. I think either way, Gatorade or just a glucose drink would be fine.

BTW, I could be wrong but from what I have seen it's not the the insulin spike that shuttles more into the cell because once the transporter is saturated eating all the sugar in the world won't cause a higher uptake. Glucose Intake does show help in retaining creatine, see Green A, Simpson E, Littlewood J, Macdonald I, Greenhaff P. (Carbohydrate ingestion augments creatine retention during creatine feedings in humans.)
 
That's an interesting study looking at which factors do and do not influence creatine uptake.

So Dan, you're saying that although glucose does help with creatine uptake, the reason for this is not the spike that it causes in insulin levels? Then how does it accomplish this?
 
[b said:
Quote[/b] (savagebeast @ April 19 2005,11:29)]So Dan, you're saying that although glucose does help with creatine uptake,


Then how does it accomplish this?
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What I am saying is it helps with retention not necessarily uptake. There are a ton of studies on creatine and phosocreatine content. One such study by Wilcott looked at the effect of insulin in the rat muscle fiber and found that high insulin levels did not enhance the uptake of creatine or change the ratio of phosocreatine to free creatine. Now was this because the tissue was saturated already, I don't know, but as I said in my other post all the sugar in world won't increase the uptake IF the transporter is saturated.

Now as with any system in the body I would assume creatine and phoscreatine is in a state of constant flux, meaning at any given time the saturation level is changing and and then on the downward slope of saturation if serum levels are sufficient uptake would occur, therfore re-saturating the receptor. Since insulin, from what I have seen is a mediator of the Na+-K+ pump, and IF the transporter is not saturated, insulin would have a regulatory effect through the Na+ transport system.
 
[b said:
Quote[/b] (dkm1987 @ April 19 2005,8:37)]One study I read shows it isn't degraded into creatinine until after the first six hours of digestion.
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may I ask for that one ?
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Ok, it appears that I mispoke, it's not that degradation occurs or not at a 6 hr time point but that overall the significance of converting to Creatinine is minimal during a 6 hour testing. Still it pretty much says that gut acids have little effect, so why would acidic drinks?

Acute creatine ingestion in human: consequences on serum creatine and creatinine concentrations.
Schedel JM, Tanaka H, Kiyonaga A, Shindo M, Schutz Y.

The aim of the study was to explore the effect of an acute dose of creatine (Cr) ingestion on serum Cr and serum creatinine (Crn) concentrations. Sixteen healthy subjects ingested a single dose of Cr (20 g) followed by the measurement of serum Cr and Crn concentration for 3 h up to a maximum of 6 h (n=6). In response to Cr ingestion a large rise in serum Cr concentration was observed (by 50 folds) occurring approximately 2 1/2h after the ingestion (peak value of 2.17 +/- 0.66 mmol x l(-1)). We also found a moderate but significant rise in serum Crn concentration averaging 13 % after 3 h (peak value at 99.5 +/- 10.5 micromol x l(-1)). A dose response curve obtained in two case studies, in whom different doses of Cr were ingested (0, 2.5, 5, 10, 15, 20 g and 0, 10, 20, 30 g), showed that serum Cr concentration as well as the peak time increased linearly with Cr ingestion. In addition, acute Crn ingestion (5 g) resulted in a substantial increase in serum Crn concentration (by 10 folds) but led to a minor rise in serum Cr concentration (by 2 folds). These results suggest that when acute doses of Cr are ingested in humans, the degree of conversion of exogenous Cr to Crn in the stomach and the gut can be considered as negligible following the first 6 h of ingestion. However, further studies are required to explore the prolonged effect of Cr on Crn metabolism.
 
so what it the most effective way to keep creatine levels up in the body?

5g creatine + 40g dextrose post workout?
 
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