Creatine is one of the oldest and the most common sports supplements in the market. It is being used since 2012 when it was first discovered and commercially it came in the market in 1993. Creatine is a very safe supplement that is supported by hundreds of long term studies. But since from some time, creatine is now linked with kidney damage.
One of the evergreen myths about creatine is that creatine supplementation may cause kidney damage. I call this myth evergreen because, despite of the fact, that it has been time and again proven wrong in studies, it still prevails.
The reason this myth originated was:
- Kidneys are the major detoxifying organs of the body, and once creatine is absorbed from the intestines, it will pass through the kidneys.
- Creatine is known to be processed by the kidneys. When the creatine breaks down, its by-product is creatinine, which passes out of the urine.
Now, this is common sense, that when you are taking creatine, your creatinine levels in the urine will increase. Problem was that, for a long time, increased creatinine levels in the urine have been a standard test for assessing kidney damage. So you will see an increase in creatinine levels when you are taking supplemental creatine, but this is not an indication of kidney damage.
Let’s see the studies. All the studies done so far have proven, that people with healthy kidney function, will have no effect from creatine supplementation.
- A 2011 study published in the journal Nephrology Dialysis Transplantation Plus, by a team of Turkish researchers, led by B. Taner. This was one study I found where the researchers, assessed a single 18-year-old patient, who had normal kidney function, but developed symptoms of nausea, vomiting, and stomach ache when he took creatine just for 5 days at the rate of 20grams for first five days and then 1gram/day for 6 weeks. On diagnosis, it was seen that the patient had acute renal failure. Twenty-five days after stopping the creatine supplementation, the patient recovered fully. Looking at this study, many anti-creatine protagonists will stand up cheering. But hold on. This is not how you judge a supplement or for that matter anything. What one needs to understand from the above study is:
- This study only had one patient, who was not called in for any creatine testing but had an adverse reaction from creatine intake.
- Having an adverse reaction to something doesn’t mean, that substance is bad. One could get an adverse reaction from anything. The person may be sensitive or allergic to it.
- Worse, the market is full of fake supplements, which have extremely toxic substances added to them. It may be a fake supplement, which may have caused the reaction, as there was no assessment of the supplement as such.
- No other study, even long term has proven creatine to be counterproductive for human intake, and in fact, has labeled creatine to be safe for kidneys.
- Even the researchers in the above study found that extensive research over the last decade has shown creatine to be a safe oral supplement.
- The patient was well within the normal creatine intake and had not overdosed it anytime.
- The researchers also recommend that people with kidney disease should avoid it, not normal people.
There are, however, multiple studies which have proven creatine to be absolutely safe for the kidneys:
- A 2009 study published in the Journal of Sports Science and Medicine, by a team of researchers led by R. A. Souza. The study examined the effects of high-dose of short term creatine supplementation (5gm/kg/day for 1 week) and long term creatine supplementation (1gm/kg/day for 4-8weeks) on liver and kidney in sedentary and exercised rats. The study showed mixed results: the long term creatine supplementation (4-8weeks) may adversely affect kidney and liver structure and function of sedentary rats. But no such effect was seen in exercising rats.
- A randomized, double-blind, placebo-controlled study, was published in the Journal of International Society of Sports Nutrition, by a team of researchers led by R. Lugaresi, in 2013. The participants were given either creatine (20gm/day for 5 days followed by 5gm/day throughout the trial) or a placebo for 12 weeks. All the participants underwent resistance training throughout the period and ate a high-protein diet. After 12 weeks there was no effect on kidney function of the subjects taking creatine.
- A 2011 study published in the European Journal of Applied Physiology, by a team of Brazilian researchers, led by B. Gualano. This was a randomized, double-blind, placebo-controlled study to assess the effects of creatine supplementation on kidney function in type-2 diabetic patients. The patients were allocated to randomly have creatine or a placebo for 12 weeks. All the patients were exercising during the study. The study found no effect of creatine supplementation on the kidney function of diabetic patients, which opens up a new window for research, for the therapeutic use of creatine on diabetic patients.
- In another study performed on the postmenopausal women (age, 58+3years), published in the journal Applied Physiology, Nutrition and Metabolism, in 2011, by a team of Brazilian researchers, gave either creatine (20gm/day for 1 week and 5gm/day thereafter) or a placebo for 12 weeks. Again there was no effect seen on the kidney function or filtration rates of these women.
- American researchers K. A. Pline & C. L. Smith, published a study in June 2005, in Annals of Pharmacotherapy. According to the study, supplementation with large doses of creatine may falsely elevate creatinine concentrations. The study of research papers on creatine between 1996 and 2004, was carried out. The study found that, because creatine is converted to creatinine in the body, supplementation with large doses of creatine may falsely elevate creatinine concentrations. Creatinine levels were minimally affected by long term creatine supplementation.
- A 2010 study in the American Journal of Kidney Disease, by B. Gualano and fellow researchers. This was a short term study to assess the effects of creatine supplementation on a person with a single kidney. A 20yr old man was given creatine supplementation for 35 days (20gm/day for 5 days followed by 5gm/day for next 30days). There was no effect of short term creatine supplementation on a person even with a single kidney.
- American researchers Persky & Rawson, published a study in Subcellular Biochemistry, in 2007, in which they concluded that the majority of the clinical studies fail to find an increased incidence of side effects with creatine supplementation. Studies have not found clinically significant deviations from normal values in renal, hepatic, cardiac or muscle function. Persky and Rawson, also found that creatine has no adverse effects on renal health in individuals ingesting creatine supplements for up to five years.
- A slightly older study done in 1999, by Belgian researchers Poortmans & Francaux, published in the Medical Science in Sports & Exercise, studied the long term effects (10 months – 5 years) in a control group. They found that neither short term, or medium-term, nor long term oral creatine supplementation induced detrimental effects on the kidney of healthy individuals.
- A 2008 randomized, double-blind, placebo-controlled study published in the European Journal of Applied Physiology, by B. Gualano and fellow researchers, evaluates the effects of creatine supplementation (10gm/day) on renal function in healthy sedentary males (18-35year old) submitted to exercise training for 3 months. A high dose of creatine supplementation over 3 months does not provoke any renal dysfunction in healthy males undergoing aerobic training.
- A 2003 study published in the journal Nephrology Dialysis Transplantation, by a Belgian research team led by Y. E. C. Taes, investigated the effect of prolonged creatine ingestion on renal function in rats with normal kidney function or pre-existing kidney failure. Creatine supplementation does not impair kidney function in animals with pre-existing renal failure or in control animals.
- A 2004 study published in the Journal of Herbal Pharmacotherapy, by American researchers Yoshizumi & Tsourounis, suggests that, according to the existing literature, creatine supplementation appears safe when used by healthy adults at the recommended loading (20 gm/day for five days) and maintenance doses (3 gm/day). In people with a history of renal disease or those taking nephrotoxic medications, creatine may be associated with an increased risk of renal dysfunction. Also, since creatine supplementation may increase creatinine levels, it may act as a false indicator of renal dysfunction.
Though animal studies have supported the use of creatine even with renal diseases, the overall studies are not well clear related to kidney damage. There are studies that label creatine to be safe, but don’t support the use of creatine in people with renal disease. A 2001 study published in the American Journal of Kidney Disease, by J.W. Edmunds and other researchers, suggests that creatine should be used with caution in people with renal disease.
Conclusion: Both short and long term studies, with low, medium and large doses of creatine have proven creatine to be a safe supplement for people with normal kidney function. Creatine doesn’t cause kidney damage. People with pre-existing kidney disease may need to consult their physicians before administering creatine. It would be better to use creatine with workouts. Taking creatine while resting on your couch may just make you a better couch potato and nothing more.