Figure 1: Chemical Structure of Creatine
Assuming you’re not a true vegan, foods such as meat, fish, and milk should be on your grocery list of creatine-providing sources. For example, 2.2 pounds (1 kg) of raw meat contains approximately 4 grams (g) of creatine. To put things into perspective, you’d have to eat approximately 9 raw Quarter Pounders from McDonald’s to derive just 4 grams of creatine; that’s friggin’ McQueasy.
Here’s the Proof!
While widespread use of creatine as a dietary supplement did not occur until the early 1990’s, elite athletes have utilized creatine as an ergogenic aid since the 1960’s. Since the marketing of creatine supplements in 1992, there have been anecdotal reports and concerns that creatine supplementation may cause muscle cramping, muscle strains, dehydration, suppression of creatine synthesis, and a multitude of undetermined negative side-effects. To date, the only documented side effect reported in the scientific community has been weight gain [1,2,3,4]. Imagine that. You gain weight!
Recently, extensive research has been conducted to investigate a number of health/medical concerns. This research has shown no negative side effects in the areas of endogenous creatine synthesis [5-6], renal and liver function, [7-16] muscle and liver enzyme efflux, [7,9,10] blood volume [17,18-20] and electrolyte status, [10,21,22] blood pressure, [23] or general markers of medical safety. [2,7,9,18,20,23,24,25]
Real World Application
Considering all the safety studies that appear in the literature to date, one study deserves applause because of its combined laboratory and practical value within the scientific community. In this classic safety study, scientists [10] examined 98 Division IA college football players who did or did not ingest creatine over a twenty-one month time period. These athletes ingested 15.75 grams of creatine during a loading phase followed by 5 grams a day thereafter during the maintenance phase while participating in intense training and competition. Creatine users and non-users were evaluated on metabolic markers, muscle and liver enzymes, electrolytes, lipid profiles, hematological markers, lymphocytes and renal markers. The bottom line, this research revealed that short and long term creatine supplementation did not adversely affect markers of clinical health status between athletes who ingested creatine and athletes who did not during intense training and competition.
Creatine Supplementation: Athletic Injuries & Conditions
Anecdotal reports have also surfaced regarding creatine supplementation during intense training in hot/humid environments. Guess what? It’s bullshit! These reports suggest that creatine may predispose athletes to increase incidence of muscle cramping, dehydration, and or musculoskeletal injuries such as muscle strains. [26-28] Baloney, I say [29]. Here’s the proof!
Ninety-eight athletes participating in the 1998-2000 football seasons who did or did not ingest creatine following workouts and practices (15.75 g of creatine for 5-d followed by ingesting an average of 5 g/d thereafter administered in 5-10 g doses) were evaluated. These athletes practiced or played in environmental conditions ranging from 8 to 40 °C (mean 24.7±5 °C) and 19 to 98% relative humidity (49.3±17%). Shit. That’s hotter than the Texas sun; oh yeah right, it was in Texas where they did this study.
It was found that creatine users had fewer incidence of cramping (37 incidence by creatine users to 96 incidence by non-users, 39%), heat/dehydration (8 to 28, 36%), muscle tightness (18 to 42, 43%), muscle pulls/strains (25 to 51, 49%), non-contact joint injuries (44 to 32, 33%), contact injuries (39 to 104, 44%), illness (12 to 27, 44%), number of missed practices due to injury (19 to 41, 46%), players lost for the season (3 to 8, 38%), and total injuries/missed practices (205 to 529, 39%). It was concluded that creatine supplementation does not increase the incidence of injury or cramping in Division IA college football players. Mmm…so much for the cramping.
In a closely related study [30], investigators examined the effects of creatine supplementation on cramping and injury occurrence in 38 Division IA football players over a single competitive season. The findings in this study revealed that the incidence of cramping, dehydration, muscle tightness, muscle strains, and total injuries among creatine users were significantly less than the non-users. Did you see that? Less, not more. Less…mmm…read on.
Finally, researchers examined the effects of creatine supplementation on cramping and injury of 21 Division I collegiate baseball players during six months of training and/or competition. [31] These athletes ingested 15 to 25g/d of creatine for 5-d followed by 5 g/d of creatine after practices or games. Environmental conditions for these athletes during training and competition ranged from 27 to 35 °C (mean 30.4±0.6 °C) and 59 to 91% relative humidity (77.1±2.53%). While no heat/dehydration events were reported for either group, the creatine-users had significantly fewer total injuries than the non-creatine users. Do you see a pattern?
Creatine Used In The Medical Community?
Due to the vast number of existing studies revolving around the ergogenic benefits of creatine supplementation, some professionals believe now is the time to investigate the potential therapeutic role that creatine ingestion may have in treating various medical conditions. Since a small percentage of creatine is stored in the heart, initial research has considered the effects of oral creatine and intravenous creatine phosphate on heart function in clinical heart patients [32,33] and populations with creatine deficiencies. [34-41] Because creatine supplementation has shown to be extremely effective in promoting muscle mass gains in healthy populations, investigators have evaluated the effects of creatine ingestion with select neuromuscular diseases such as Huntington’s disease [42,43], amyotrophic lateral sclerosis [44,45] and Duchannes Muscular Dystrophy. [46-48] Investigators have also considered the potential effects creatine may have with brain and spinal cord injured patients [49-51] as well as the reduction of atrophy due to immobilization. [52-54] Further, investigators have considered creatine’s therapeutic role as a method to reduce cholesterol [55,56] and homocysteine levels. [57,58]
Take Home Message
While additional research is always warranted, the existing data suggests that creatine supplementation is a safe and effective nutritional strategy to not only enhance exercise/athletic performance but aid in the treatment of various medical conditions. And for the boneheads who say that creatine causes cramps, renal problems, and your babies to be born with two heads, tell ‘em they’re nuts! The proof is in the science.
References
-
1. Noonan, D., et al., Effects of varying dosages of oral creatine relative to fat free body mass on strength and body composition. J Strength Cond Res, 12(2), 104, 1998.
2. Peeters, B.M., Lantz, C.D., and Mayhew, J.L., Effect of oral creatine monohydrate and creatine phosphate supplementation on maximal strength indices, body composition, and blood pressure. J Strength Cond Res, 13(1), 3, 1999.
3. Terjung, R.L., et al., American College of Sports Medicine roundtable. The physiological and health effects of oral creatine supplementation. Med Sci Sports Exerc, 32(3), 706, 2000.
4. Earnest, C.P., et al., The effect of creatine monohyerate ingestion on anaerobic power indices, muscular strength and body composition. Acta Physiol Scand, 153, 207, 1995.
5. Vandenberghe, K., et al., Long-term creatine intake is beneficial to muscle performance during resistance training. J Appl Physiol, 83(6), 2055, 1997.
6. Tarnopolsky, M., et al., Acute and moderate-term creatine monohydrate supplementation does not affect creatine transporter mRNA or protein content in either young or elderly humans. Mol Cell Biochem, 244(1-2), 159, 2003.
7. Robinson, T.M., et al., Dietary creatine supplementation does not affect some haematological indices, or indices of muscle damage and hepatic and renal function. Br J Sports Med, 34(4), 284, 2000.
8. Poortmans, J.R., et al., Effect of short-term creatine supplementation on renal responses in men. Eur J Appl Physiol Occup Physiol, 76(6), 566, 1997.
9. Schilling, B.K., et al., Creatine supplementation and health variables: a retrospective study. Med Sci Sports Exerc, 33(2), 183, 2001.
10. Kreider, R.B., et al., Long-term creatine supplementation does not significantly affect clinical markers of health in athletes. Mol Cell Biochem, 244(1-2), 95, 2003.
11. Taes, Y.E., et al., Creatine supplementation does not affect kidney function in an animal model with pre-existing renal failure. Nephrol Dial Transplant, 18(2), 258, 2003.
12. Poortmans, J.R. and Francaux, M., Adverse effects of creatine supplementation: fact or fiction? Sports Med, 30(3), 155, 2000.
13. Kuehl, K., et al., Effects of oral creatine monohydrate supplementation on renal function in adults. Med Sci Sports Exerc, 32(5), S168, 2000.
14. Poortmans, J.R. and Francaux, M., Long-term oral creatine supplementation does not impair renal function in healthy athletes. Med Sci Sports Exerc, 31(8), 1108, 1999.
15. Poortmans, J.R. and Francaux, M., Renal dysfunction accompanying oral creatine supplements. Lancet, 352(9123), 234., 1998.
16. Earnest, C.P., Almada, A., and Mitchell, T.L., Influence of chronic creatine supplementation on hepatorenal function. FASEB J, 10, A790, 1996.
17. Volek, J.S., et al., Physiological responses to short-term exercise in the heat after creatine loading. Med Sci Sports Exerc, 33(7), 1101, 2001.
18. Kreider, R., et al., Long-term creatine supplementation does not significantly affect clinical markers of health in athletes. Mol Cell Biochem, 244, 95, 2003.
19. Greenwood, M., et al., Creatine supplementation patterns and perceived effects in select division I collegiate athletes. Clin J Sport Med, 10(3), 191, 2000.
20. Oopik, V., et al., Effect of creatine supplementation during rapid body mass reduction on metabolism and isokinetic muscle performance capacity. Eur J Appl Physiol Occup Physiol, 78(1), 83, 1998.
21. Kreider, R.B., et al., Effects of creatine supplementation on body composition, strength, and sprint performance. Med Sci Sports Exerc, 30(1), 73, 1998.
22. Volek, J.S., et al., Physiological response to exercise in the heat after loading with creatine monohydrate. Journal of Strength and Conditioning Research, 14(3) 2000.
23. Mihic, S., et al., Acute creatine loading increases fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men and women. Med Sci Sports Exerc, 32(2), 291, 2000.
24. Poortmans, J.R. and Francaux, M., Long-term oral creatine supplementation does not impair renal function in healthy athletes. Med Sci Sports Exerc, 31(8), 1108, 1999.
25. Stone, M.H., et al., A retrospective study of long-term creatine supplementation on blood markers of health. J Strength Cond Res, 13(4), 433, 1999.
26. Greenwood M, Farris J, Kreider R, Greenwood L, Byars A. Creatine supplementation patterns and perceived effects in select division I collegiate athletes. Clin J Sport Med. 10:191-194, 2000.
27. Juhn MS, O'Kane JW, Vinci DM. Oral creatine supplementation in male collegiate athletes: a survey of dosing habits and side effects. J Am Diet Assoc. 99:593-595, 1999.
28. LaBotz M, Smith BW. Creatine supplement use in an NCAA Division I athletic program. Clin J Sport Med. 9:167-169, 1999.
29. Greenwood M, Kreider R, Melton C, Rasmussen C, Lancaster S, Cantler E, Almada A. Creatine supplementation during college football training does not increase the incidence of cramping or injury. Molecular and Cellular Biochemistry, 244: 83-88, 2003.
30. Greenwood M, Kreider R, Greenwood L, Byars A. Cramping and injury incidence are not increased by creatine supplementation in collegiate football players. Journal of Athletic Training (In Press, 2003).
31. Greenwood M, Kreider R, Greenwood L, Byars A. Creatine supplementation does not increase the incidence of injury or cramping in college baseball players. Journal of Exercise Physiology: Online (In Press, 2003).
32. Witte, K.K., Clark, A.L., and Cleland, J.G., Chronic heart failure and micronutrients. J Am Coll Cardiol, 37(7), 1765, 2001.
33. Andrews, R., et al., The effect of dietary creatine supplementation on skeletal muscle metabolism in congestive heart failure. Eur Heart J, 19(4), 617, 1998.
34. Ganesan, V., et al., Guanidinoacetate methyltransferase deficiency: new clinical features. Pediatr Neurol, 17(2), 155, 1997.
35. Stockler, S. and Hanefeld, F., Guanidinoacetate methyltransferase deficiency: A newly recognized inborn error of creatine biosynthesis. Wiener Klinische Wochenschrift, 109(3), 86, 1997.
36. Stockler, S., et al., Creatine deficiency in the brain: A new, treatable inborn error of metabolism. Pediatric Research, 36, 409, 1994.
37. Stockler, S., et al., Guanidino compounds in guanidinoacetate methyltransferase deficiency, a new inborn error of creatine synthesis. Metabolism, 46, 1189, 1997.
38. Stockler, S., Hanefeld, F., and Frahm, J., Creatine replacement therapy in guanidinoacetate methltransferase deficiency, a novel inborn error of metabolism. Lancet, 21(348), 789, 1996.
39. Stockler, S., et al., Guanidinoacetate methltransferase deficiency: The first inborn error of creatine metabolism in man. American Journal of Human Genetics, 58, 914, 1996.
40.Schulze, A., et al., Improving treatment of guanidinoacetate methyltransferase deficiency: reduction of guanidinoacetic acid in body fluids by arginine restriction and ornithine supplementation. Mol Genet Metab, 74(4), 413, 2001.
41. Battini, R., et al., Creatine depletion in a new case with AGAT deficiency: clinical and genetic study in a large pedigree. Mol Genet Metab, 77(4), 326, 2002.
42.Leuzzi, V., Inborn errors of creatine metabolism and epilepsy: clinical features, diagnosis, and treatment. J Child Neurol, 17 Suppl 3, 3S89, 2002.
43. Wyss, M. and Schulze, A., Health implications of creatine: can oral creatine supplementation protect against neurological and atherosclerotic disease? Neuroscience, 112(2), 243, 2002.
44. Dedeoglu, A., et al., Creatine therapy provides neuroprotection after onset of clinical symptoms in Huntington's disease transgenic mice. J Neurochem, 85(6), 1359, 2003
45. Derave, W., et al., Skeletal muscle properties in a transgenic mouse model for amyotrophic lateral sclerosis: effects of creatine treatment. Neurobiol Dis, 13(3), 264, 2003.
46. Drory, V.E. and Gross, D., No effect of creatine on respiratory distress in amyotrophic lateral sclerosis. Amyotroph Lateral Scler Other Motor Neuron Disord, 3(1), 43, 2002.
47. Tarnopolsky, M.A., Potential use of creatine monohydrate in muscular dystrophy and nuerometabolic disorders. Abstracts of 6th Internationl Conference on Guanidino Compounds in Biology and Medicine,2001.
48. Tarnopolsky, M.A. and Parise, G., Direct measurement of high-energy phosphate compounds in patients with neuromuscular disease. Muscle Nerve, 22(9), 1228, 1999.
49. Walter, M.C., et al., Creatine monohydrate in myotonic dystrophy: a double-blind, placebo-controlled clinical study. J Neurol, 249(12), 1717, 2002.
50. Adcock, K.H., et al., Neuroprotection of creatine supplementation in neonatal rats with transient cerebral hypoxia-ischemia. Dev Neurosci, 24(5), 382, 2002.
51. Sullivan, P.G., et al., Dietary supplement creatine protects against traumatic brain injury. Ann Neurol, 48(5), 723, 2000.
52. Matthews, R.T., et al., Creatine and cyclocreatine attenuate MPTP neurotoxicity. Exp Neurol, 157(1), 142, 1999.
53. Hespel, P., et al., Oral creatine supplementation facilitates the rehabilitation of disuse atrophy and alters the expression of muscle myogenic factors in humans. J Physiol, 536(Pt 2), 625, 2001.
54. Op 't Eijnde, B., et al., Effect of oral creatine supplementation on human muscle GLUT4 protein content after immobilization. Diabetes, 50(1), 18, 2001.
55. Volek, J.S., et al., No effect of heavy resistance training and creatine supplementation on blood lipids. Int J Sport Nutr Exerc Metab, 10(2), 144, 2000.
56. Earnest, C.P., Almada, A., and Mitchell, T.L., High-performance capillary electrophoresis-pure creatine monohydrate reduced blood lipids in men and women. Clinical Science, 91, 113, 1996.
57. Stead, L.M., et al., Methylation demand and homocysteine metabolism: effects of dietary provision of creatine and guanidinoacetate. Am J Physiol Endocrinol Metab, 281(5), E1095, 2001.
58. McCarty, M.F., Supplemental creatine may decrease serum homocysteine and abolish the homocysteine 'gender gap' by suppressing endogenous creatine synthesis. Med Hypotheses, 56(1), 5, 2001.
