Creatine side effects: Fact or fiction?
Creatine has established itself as one of the most effective and popular supplements available for people wanting to build muscle and improve performance. However, there are concerns that creatine is unsafe. Are the stories about creatine side effects that often appear in the popular press based on fact or fiction?
Creatine is a very popular supplement. That's mainly because it accelerates gains in muscle size and strength compared to exercise alone. In a 12-week trial by Jeff Volek and a research team from Pennsylvania State University, creatine users ended up stronger in both the squat and bench press compared with subjects using a "dummy" supplement. They also gained twice as much muscle.
There are claims that creatine users are more susceptible to cramps, muscle spasms, and even pulled muscles. However, in a three-year study designed to find out whether these creatine side effects really do exist, creatine had no effect on the incidence of injury or cramping in a group of American footballers.
Research published in the journal Medicine and Science in Sports and Exercise shows similar results. In a group of 26 athletes using creatine for up to four years, there was no difference in the reported incidence of muscle cramp or injury compared with athletes not using creatine.
A more recent study, published in the September 2004 issue of the International Journal of Sports Medicine, also shows that creatine side effects are rare.
A group of 175 subjects received either 10 grams of creatine or placebo daily for an average period of 310 days. Diarrhea and nausea did cause three subjects to stop using creatine. But there were no other significant differences between the groups.
Researchers from Truman State University also report that long-term creatine use appears to be safe.
Twenty-three members of an NCAA Division II American football team were divided into a creatine group and a control group who took no supplements.
Subjects in the creatine group averaged 14 grams of creatine a day for three years. However, the researchers could find no detrimental effects on either kidney or liver function.
When I started using creatine in 1996, I can still remember one occasion when I suffered from extremely painful muscle cramps. After teaching a 45-minute exercise class in a hot and humid swimming pool hall, the first thing I should have done was get something to drink. But I didn't. Instead, I went straight into the office and sat down to read a newspaper.
Suddenly, the back of my left thigh started to cramp up. So, I straightened my leg to try to ease the pain. Then, the front of my thigh started to cramp as well. I didn't know what to do. I couldn't bend or straighten my leg — so I just sat there hoping the pain would go away.
Of course, I have no idea whether or not creatine contributed to the problem. Scientists aren't really sure what causes cramp in the first place. But up until then, I'd never experienced such painful cramps in the front and back of my thigh at the same time. Now, I always make sure to carry a bottle of water with me when I go to the gym.
Most people aren't aware that creatine has protective effects in heart, muscle and neurological diseases. In fact, several months of creatine supplementation in men and women with borderline high cholesterol levels reduces very-low-density lipoprotein levels (the so-called "bad" cholesterol) by almost one-third.
Similar findings are reported in the journal Metabolism. Twenty-eight days of creatine supplementation and resistance exercise lowered total cholesterol levels to a greater extent than resistance exercise alone.
Carefully controlled studies over the short- (five days), medium- (nine weeks) and long-term (up to five years) have yet to demonstrate that creatine supplementation has any adverse effects on blood pressure, kidney or liver function in healthy individuals.
Of course, an absence of evidence is not evidence of absence. The fact that large trials have yet to find any serious creatine side effects doesn't mean that none exist. There are isolated case reports of individuals suffering from kidney problems after using creatine. Anyone with existing liver or kidney problems, or those predisposed to such ailments, should seek medical advice before using creatine.
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An updated version of the special report Creatine Supplements: What works and what doesn't? has also just been published.
The report now includes a detailed review of the research linking creatine with a reduced rate of fat loss, and also reveals which three popular creatine supplements failed to meet label claims.
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