Prescriptions
Creatine use could be more harmful than helpful
By Landis Lum
While suffering acute breathlessness trying to guard Paul, a 6-foot-4 pediatric intern, at a basketball game with our "Over the Hill Gang," I thought about whether I should begin taking creatine to enhance my athletic performance. Indeed, most (but not all) studies show that this supplement improves exercise that involves short, repetitive periods of extremely powerful activity.
Creatine does bring about an enhanced accrual of strength in weight-lifting programs. However, creatine will not improve aerobic exercise performance or maximal isometric strength.
How does creatine work? When you eat food, your body breaks it down into packets of energy called adenosine triphosphate, or ATP, that muscles and organs can use.
However, to make ATP, the body needs a ready supply of something called phosphocreatine, and as muscle stores of this get low, athletic performance suffers. Extra creatine can increase these muscle stores in most people, leading to faster regeneration of ATP and decreased rest time between exercise bouts.
However, a study published in January in the American Journal of Kidney Diseases looked at the so-called Han: Sprague-Dawley rat, a special kind of rat used for research on human polycystic kidney disease, which leads to kidney failure. The rats were given creatine in a dose similar to that taken by athletes (a high dose for one week, then a lower dose for five weeks). These rats not only had worsening kidney function, but also increased formation of cysts in their kidneys.
What does this mean? Creatine should be avoided by humans who have underlying kidney disease; even in people with normal kidneys, the safety of long-term creatine supplementation is unknown.
Evidently this risk doesn't deter elite athletes. In an editorial to this study, Sandra Sabatini, who is one of the journal editors, commented that at the time of the 1996 Olympic games in Atlanta, a group of athletes was asked: "If you were given an agent that guaranteed you would win a gold medal but was guaranteed to kill you one year later, would you take it?" More than 80 percent said yes!
Other possible dangers of creatine are influences on insulin production. And when creatine is made, variable amounts of contaminants such as dicyandiamide, dihydrotriazines, creatinine and ions are made, and their safety is unknown.
Weight gain of 2 to 6 pounds is common from increased body water. Creatine monohydrate is not dehydrating and may be safer. Finally, because the Food and Drug Administration does not regulate creatine supplements, you can never be sure about their purity, dosage or safety.
The usual dosage is 5 grams four times a day for five to seven days, followed by 5 grams a day.
However, in March 2000, two separate articles disputed the need for a dosage this high. Ronald Terjung, a professor of physiology at the University of Missouri, reported in the medical journal Medicine & Science in Sports and Exercise that a dose of 20 grams a day is not needed, as 3 grams a day caused the same increase in muscle phosphocreatine content given time; the result can be enhanced if you consume carbohydrates at the same time.
Gian Benzi, a professor at the University of Pavia, Italy, agreed in the medical journal Pharmacology Research: "In healthy athletes submitted daily to high intensity strength or sprint training, the maximal oral creatine dose should be about two times the daily turnover, i.e., less than 5 to 6 grams per day for less than two weeks, and taken under medical supervision."
The American College of Sports Medicine Roundtable recently concluded that although there was no "definitive" evidence that creatine supplementation was harmful, that "lack of information cannot be taken as assurance" that creatine supplementation is free from risks, and "the fact that creatine is a naturally occurring compound does not make supplementation safe, as numerous compounds are good, even essential in moderation, but detrimental in excess."
Well, I have decided not to take creatine. By the way, my gang is looking for an indoor gym to encourage certain of our (aging) members to continue to participate week after week, so please contact me if you have any leads.
Dr. Landis Lum is a family practice physician with Kaiser Permanente, and an associate clinical professor of family and community medicine at the University of Hawai'i's John A. Burns School of Medicine.
Hawai'i experts in traditional medicine, naturopathic medicine, diet and exercise take turns writing the Prescriptions column. Send your questions to: Prescriptions, 'Ohana Section, The Honolulu Advertiser, P.O. Box 3110, Honolulu, HI 96802; e-mail ohana@honoluluadvertiser.com; fax 535-8170. This column is not intended to provide medical advice; you should consult your doctor.
