Creatine is the most extensively researched food supplement on the market and works for 80 percent of users. It’s specific for anaerobic exercise, such as bodybuilding, and helps maintain optimal levels of the immediate source of energy for muscle contraction, adenosine triphosphate—a.k.a. ATP. Energy is produced when a phosphate group is released from ATP, and creatine helps regenerate the depleted ATP molecule by contributing a phosphate molecule. Creatine also aids intense training by providing a buffering action in muscle, which lowers the acidity that fatigues muscle. As if all that weren’t enough, creatine boosts intracellular water, which aids anabolic processes in muscle.
Based on research, most people thought the best way to use creatine was to load 20 to 30 grams for five to six days—that is, 0.3 grams of creatine per kilogram of bodyweight—usually in five-gram doses, or about a teaspoonful. After the initial load the dose goes down to 0.03 grams per kilogram of bodyweight, or about three grams a day. Originally, that dose was thought to be the fastest way to load muscles. Later research, however, refined the technique. Several studies showed that you can increase muscle creatine simply by taking five grams of creatine for 30 days. That results in less water retention, as the typical creatine loading phase can add anywhere from five to 10 pounds of water. Later studies also found that creatine loading was effective for only the first 48 hours. After that the majority of the creatine taken in was rapidly excreted.
Some early studies also indicated that taking creatine with a simple, or rapidly absorbed, sugar source aided uptake. The mechanism involved sugar-stimulated insulin release. Insulin, in turn, was thought to activate the creatine transporter in muscle, which is the rate-limiting factor in muscle-creatine uptake. While the insulin theory hasn’t been completely discarded, it turned out that insulin was only a minor player. The real stimulus is a mechanism called the sodium pump. As the name implies, it is powered by sodium, not sugar. Other research demonstrated that taking creatine with a fast-acting protein, such as whey, was as effective as taking it with a simple sugar. That made sense because amino acids contained in whey also trigger an insulin release, which then turns on the sodium pump, leading to creatine uptake.
Clearly, the formula for the best way to take creatine is evolving. A recently published study, for example, used a double-blind design—that is, neither the researchers nor the subjects initially knew which was the creatine and which was the placebo. Thirty-two men received either five grams of creatine and four grams of phosphate or a placebo consisting of 20 grams of dextrose, a sugar. Researchers tested the subjects’ anaerobic-training capacity after 30 days. There were no differences in anaerobic-training ability between the creatine and placebo groups. The only change was a weight gain of one kilogram—2.2 pounds—in those who used the real creatine, which occurred after 10 days. Those in the placebo group didn’t experience any weight change.
Based on those results, the authors suggest that using low-dose creatine for 30 days provides no ergogenic or significant training effects. Noting that the loading phase is useless after 48 hours, they think that it’s best to load creatine for two days, then switch to a maintenance dose. For those who can’t tolerate a loading phase, another option is to take eight to 10 grams of creatine a day for about 10 weeks. Anything less than five grams a day, say the authors, is not effective for boosting anaerobic performance.
Another new study examined the occurrence of gastrointestinal distress in creatine users. Anecdotal reports indicate that some users experience stomach cramps, diarrhea and nausea. The question is, Are the side effects related to dosage? To find out, researchers randomly assigned 59 elite professional soccer players to a group that got two five-gram doses of creatine a day, a group that got one 10-gram dose over a 28-day period or a group that got a placebo containing no creatine.
In all three groups the most common side effects were diarrhea (39 percent), stomach upset (23.8 percent) and belching (16.9 percent). There was no difference, however, in the incidence of side effects between the five-gram creatine group and the placebo group. On the other hand, the incidence of diarrhea was far higher—over 20 percent more—in the 10-gram creatine group. Accordingly, the authors contend that taking more than five grams of creatine as a single dose can lead to gastrointestinal side effects.
Why would larger doses of creatine cause such effects? Creatine is an amino acid product synthesized in the body from three amino acids—arginine, glycine and methionine—chiefly in the liver, pancreas and kidneys. Although all commercial creatine supplements are synthetic, which makes them suitable for vegetarians, they retain their amino acid characteristics. Concentrated amino acids, when taken orally, draw water into your gut. Accumulate enough water, and presto—you have the gastrointestinal side effects. The effect is more likely to occur with larger individual doses of creatine because the creatine particles may not completely dissolve.
In other cases the culprit may be a low grade of creatine, the processing of which yields several potentially toxic by-products, including sodium sarcosine, cynamide, dicyandiamide and dihydrotriazine creatinine. During quality control the toxins are supposed to be filtered out. Even so, they may be present in cheaper brands, especially those from China—a country notorious for shoddy quality control, as we discovered in last year’s tainted-pet-food episode. In contrast, creatine manufactured in either the United States or Germany is usually highly purified and free of contaminants. Finally, consider that the side effects in the study were similar for those who took either five grams of creatine or a placebo. That should tell you something right there.
A new case study might cause concern in those who take both creatine and whey. A 27-year-old man developed kidney failure and serious liver problems after allegedly taking popular bodybuilding supplements, specifically a popular brand of whey powder, a popular nitric oxide-and-creatine mixture and a popular brand of creatine. He had no family or personal history of liver disease and claimed to not use any recreational drugs or alcohol. Tests showed that he had severe jaundice, traced to a blockage of bile in his liver. He’d been using creatine for eight to nine months prior to his symptoms, which peaked when he added the whey supplement. Based on that, the authors speculate that the supplements caused his medical problems.
On the other hand, the authors cite research showing that, if anything, whey protein reduces liver inflammation. Whey is also known to lower liver enzymes in some cases of hepatitis B. The authors also say that studies implicating whey or creatine or both as a cause of that kind of problem “are far from robust.” Translation: They don’t exist! They write off the man’s problem as an idiosyncratic reaction to the supplements, meaning that it may pertain only to him and no one else. Based on the safe and medically uncomplicated use of both whey and creatine, as well as nitric oxide supplements, by countless people, I’d say that’s an accurate assumption.
Here’s the kicker: They didn’t test the guy for oral anabolic steroids. In fact, there was no mention of anabolic steroids in the entire case study. Cholestatic jaundice is a common side effect of oral anabolic steroid use. Could it be that the guy was a surreptitious—and unadmitted—steroid user? In their zeal to label commonly used bodybuilding supplements as potentially toxic, the physicians conducting the study conveniently sidestepped the steroid issue. So this case study is rated G for garbage. IM
Eckerson, J.M., et al. (2008). Effect of thirty days of creatine supplementation with phosphate salts on anaerobic working capacity and body weight in men. J Str Cond Res. 22:826-32.
Ostojic, S.M., et al. (2008). Gastrointestinal distress after creatine supplementation in athletes: Are side effects dose dependent? Res Sports Med. 16:15-22.
Whitt, K.N., et al. (2008). Cholestatic liver injury associated with whey protein and creatine supplements. Semin Liver Dis. 228:226-32.