Creatine is a potentially effective muscle-building supplement that boosts your athletic performance by increasing the amount of phosphocreatine you store in your muscles. When you perform intense exercise over a short period of time, such as lifting heavy weights, this phosphocreatine creates the energy source ATP, thus improving your strength. The downside of creatine is that it is potentially harmful to your kidneys in a number of ways, including the creation of kidney stones.
Water Reduction
One way creatine negatively impacts your kidneys and can lead to kidney stones is by drawing extra water into your muscles. Though this gives you a muscular look, it also increases the concentration of your urine. Case Western Reserve University notes that as your urine concentration increases, it becomes increasingly likely that minerals like calcium oxalate will bond together to form kidney stones.
Effect on Kidneys
One 2001 study that appeared in the American Journal of Kidney Diseases examined creatine supplementation in rats with kidney disease. During the six-week trial, rats receiving doses similar to those used by humans for strength-training purposes showed signs of their kidney disease advancing. The researchers conclude that people with reduced kidney function, such as those who are predisposed toward kidney stones, should avoid taking creatine supplements.
Impurities
Sports nutrition specialist Mark Jenkins, M.D., states that another area of concern with creatine, as with any supplement, is impurities in the formula. The U.S. Food and Drug Administration does not regulate creatine supplements, and therefore the quality of these supplements can vary widely. Long-term side effects from these impurities, particularly how they affect your kidneys, are not known.
Treating Kidney Stones
You should immediately stop your creatine supplementation program if you experience the symptoms of kidney stones, such as flank pain. Your doctor may test your creatinine levels to determine if you have kidney stones. Inform her that you have been taking a creatine supplement so the medical staff can take this into account with your results. Ceasing your creatine consumption will increase your fluid levels, as will drinking more water. Your doctor may also prescribe you pain medication as you pass the kidney stones.
References
- University of Cincinnati, Net Wellness: Kidney Stones; Martin I Resnick, M.D.; September 2009
- New York University: Creatinine and Creatinine Clearance; Monica Rhodes; August 2008
- MedlinePlus: Creatine; January 2011
- American Journal of Kidney Diseases: "Creatine Supplementation Increases Renal Disease Progression in Han:SPRD-cy Rats"; Jeff W. Edmunds, M.Sc., R.D. et al; January 2001
- Rice University: Creatine Supplementation in Athletes; Mark A. Jenkins, M.D.
- University of Maryland Medical Center: Creatine; Steven D. Ehrlich, NMD; June 2009
