Is Creatine Healthy For Our Kidneys?

Uh oh.

Just recently some researchers tried to feed the world the notion that creatine was linked to testicular cancer in some observational research.

They put creatine in the category of a "muscle building supplement" along with an illegal testosterone supplement, and found that use of the humble amino acid increased the risk of testicular cancer?

My thoughts on this study are clear in the link above: if they're using the illegal testosterone supplement than they're most likely using creatine too - but which one was really doing the damage?

But the authors got what they wanted - a headline.

So here's the problem for these authors, when we study creatine properly, it turns out to be pretty damn good for us.

CREATINE AND KIDNEY HEALTH - THE REAL RESEARCH

I think it's only fair we point out that when we directly examine CAUSE and EFFECT - that creatine actually has been shown to be healthy and beneficial for our kidneys.

We know how good it is for our training and progress - and you can add your kidney health to this now, too.

This study examined 9 male subjects aged between 18-35 and gave them 10 grams of creatine daily over 3 months.

This is about 4 grams more than what's typically recommended for performance (2).

Studies have shown that 5-6 grams a day is all that's required for benefits (3), but it's nice to know they used a bit more to see what would happen.

The subjects exercised for a hour, 3 times per week. 

MEAUSURING KIDNEY FUNCTION

Kidney function is measured by observing the speed of which creatinine (a waste product of creatine) vanishes from the blood.

When this happens at a faster rate in one person compared to another - this person has superior kidney function. But unfortunetly, this doesn't work for people like you and me that might be taking creatine; as we'd most likely have more creatinine in our blood.

The study used a placebo group (which took dextrose) and obviously the creatine group. As you can see by the graph below, creatinine levels were bolstered in the group who took creatine - no surprises here. 

So how did they measure kidney function?

They made sure to keep track of a protein called Cystatin C in the blood; an indicator of how well kidneys are operating.

The less you have - the better your kidneys are working!

Now....have a look at the graph below.

As the graph details - levels of Cystatin C were significantly lower in the creatine group, meaning their kidneys were functioning better!

Now it's important to point out that the amount of Cystatin C also dropped in the placebo group too following the exercise - but the researchers say that this is probably due to that - exercise.

But the fact is it dropped MORE in the creatine and exericse group compared to the exercise group alone, and this is the important finding here.

So as much as it's a victory for kidney health resulting from creatine, it's a victory for exercise too.

And let me also point out - this is not just one study - there are plenty more that will tell us creatine is safe for our kidneys (4,5,6).

To hear from some of the researchers above: (6)

"The majority of clinical studies fail to find an increased incidence of side effects with creatine supplementation." (6)

Now sure, limitations are that none of these studies are long term. But still, there's certainly no logical reasoning based on the research we have to suggest creatine would cause any issues long term.

The take-home message is pretty simple: keep taking your creatine and know that it's most likely serving your kidneys well.

 

"Stay Fit, Stay Flexed!"

 

REFERENCES

(1) Gualano B, Ugrinowitsch C, Novaes RB, Artioli GG, Shimizu MH, Seguro AC, Harris RC, Lancha AH Jr. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol. 2008 May;103(1):33-40. doi: 10.1007/s00421-007-0669-3. Epub 2008 Jan 11.

(2) Shao A, Hathcock JN. Risk assessment for creatine monohydrate. Regul Toxicol Pharmacol. 2006 Aug;45(3):242-51. Epub 2006 Jun 30.

(3) Pearson DR, Hamby DG, Russel W, Harris T: Long-term effects of creatine monohydrate on strength and power. J Strength Cond Res 13: 187–192, 1999

(4) Pline KA, Smith CL.The effect of creatine intake on renal function. Ann Pharmacother. (2005)

(5) Ropero-Miller JD, et al Effect of oral creatine supplementation on random urine creatinine, pH, and specific gravity measures. Clin Chem. (2000)

(6) Persky AM, Rawson ES Safety of creatine supplementation. Subcell Biochem. (2007)