Enzymes are specialized proteins in your body that support life by vastly increasing the speed of a wide range of basic chemical reactions. Your liver contains three prominent enzymes that can appear in elevated amounts in your bloodstream when your liver cells are damaged. Creatine, a substance naturally produced in your body and used in supplement form to improve athletic performance, does not appear to trigger liver enzyme elevation. Consult your doctor before using supplemental creatine.
Your body makes its internal creatine supply in your liver, as well as in your pancreas gland and kidneys. After creatine is created, it gets converted into another substance called phosphocreatine, or creatine phosphate, and sent to your muscles for storage. When you engage in sprinting, weightlifting or any other exercise that requires high levels of exertion for short periods of time, your body converts creatine phosphate into a major energy source called adenosine triphosphate, or ATP. Supplemental forms of creatine work in essentially the same way, and are available in products that include tablets, energy bars, powders, tablets, drink mixes and liquids.
Liver Enzyme Basics
The liver enzymes that doctors first look for in your bloodstream when assessing your liver function are alanine aminotransferase, or ALT; aspartate aminotransferase, or AST; and alkaline phosphatase, or ALP. Other liver enzymes that may appear in elevated amounts in your blood are gamma-glutamyl transferase, or GGT, and lactate dehydrogenase, or LDH. Doctors use GGT levels to help determine the underlying causes of ALP elevations. LDH levels can rise if you have liver damage or damage in other tissues in your body.
Enzyme Elevation Causes
MayoClinic.com lists relatively common causes of elevated liver enzymes that include use of acetaminophen and other nonprescription painkillers, use of statins and other prescription medications, alcohol consumption, obesity, heart failure, nonalcoholic fatty liver disease and hepatitis A, B and C. Less common causes include heart attacks, autoimmune hepatitis, alcoholic hepatitis, toxic hepatitis, liver scarring, liver cancer, pancreas inflammation, celiac disease, an underactive thyroid gland, mononucleosis, Epstein-Barr syndrome, gallbladder inflammation and muscular dystrophy. In most cases, enzyme elevations are not caused by serious, ongoing alterations in your liver function.
Creatine supplements are meant for people age 19 or older, and have not been studied in adolescents or children, according to the University of Maryland Medical Center, or UMMC. A 2002 study published in the “International Journal of Sport Nutrition and Exercise Metabolism” examined the effects of creatine supplementation on ALT, AST and ALP in college football players. The authors of the study reported no change in the levels of any of these enzymes. Another study of athletes, published in 2003 in "Molecular and Cellular Biochemistry," reported that creatine supplementation makes no significant alterations in any common health markers. Still, the UMMC identifies liver dysfunction as a potential consequence of prolonged creatine use. Before you use creatine, ask your doctor about its potential liver-related effects.
- Elmhurst College - Virtual Chembook: Roles of Enzymes in Biochemical Reactions; Charles E. Ophardt; 2003
- American Association for Clinical Chemistry - Lab Tests Online: Liver Panel; The Test
- University of Maryland Medical Center: Creatine
- "International Journal of Sport Nutrition and Exercise Metabolism": Effects of Long-Term Creatine Supplementation on Liver...Functions in American College Football Players; Mayhew, Mayhew, et al.; December 2002
- "Molecular and Cellular Biochemistry": Long-Term Creatine Supplementation Does Not Signficantly Affect Clincal Markers of Health in Athletes; Kreider, Melton, et al.; February 2003
- MayoClinic.com: Elevated Liver Enzymes (Pages 1 and 2); May 5, 2011