For more information, please read:
· Creatine Risks Noted By French Agency
· DMD - Glutamine and creatine trial in DMD
· DMD/BMD - Randomized, double-blind trial of creatine monohydrate
· DM - Randomized, double-blind trial of creatine monohydrate
Q What is creatine?
A Creatine is an amino acid (amino acids are the building blocks of protein) which is made in the body by the liver and kidneys, and is derived from the diet through meat and animal products. Creatine is categorized as a food supplement by the Food and Drug Administration (like a vitamin) and is available over the counter at drug stores and nutrition centers.
Q What does creatine normally do in the body?
A In the body, creatine is changed into a molecule called "phosphocreatine" which serves as a storage reservoir for quick energy. Phosphocreatine is especially important in tissues such as the voluntary muscles and the nervous system which periodically require large amounts of energy.
Q Why do athletes take creatine?
A Studies have shown that creatine can increase the performance of athletes in activities that require quick bursts of energy, such as sprinting, and can help athletes to recover faster after expending bursts of energy.
Q Why have I been hearing so much about creatine and neuromuscular disorders?
A Two scientific studies have indicated that creatine may be beneficial for neuromuscular disorders. First, a study by MDA-funded researcher M. Flint Beal of Cornell University Medical Center demonstrated that creatine was twice as effective as the prescription drug riluzole in extending the lives of mice with the degenerative neural disease amyotrophic lateral sclerosis (ALS, or Lou Gehrig's disease). Second, a study by Canadian researchers Mark Tarnopolsky and Joan Martin of McMaster University Medical Center in Ontario found that creatine can cause modest increases in strength in people with a variety of neuromuscular disorders. Beal's work was published in the March 1999 issue of Nature Neuroscience and the second paper was published in the March 1999 issue of Neurology.
Q Why might creatine be beneficial to those with ALS?
A Beal suspects that the neuroprotective effects of creatine in the mouse model of ALS are due either to an increased availability of energy to injured nerve cells or to a blocking of the chemical pathway that leads to cell death.
Q If creatine proves to be just as effective in human ALS as it is in mice, what sorts of gains might we expect in people?
A This question can only be answered by studying the effects of creatine in humans with ALS. MDA is currently planning a multi-center human trial to test the effectiveness of creatine.
Q I have ALS and I've been taking riluzole. Given that creatine has been reported to be more effective than riluzole in mice with ALS, should I switch my medication from riluzole to creatine?
A Please keep in mind that, although the results of the studies are promising, the effectiveness of creatine in humans with ALS hasn't yet been tested (but see "clinical trials" below for information on upcoming trials). Also, riluzole and creatine may exert their neuroprotective effects by different mechanisms. Riluzole works by inhibiting the release of the neurotransmitter glutamate, which is thought to injure nerve cells in ALS through a mechanism known as "glutamate toxicity." Creatine, on the other hand, may help cells that have already been damaged to keep going longer by providing the nerve cells with extra energy, or by preventing the damage from getting worse. Because the two compounds may work by slightly different mechanisms, researchers hope that they'll have an additive effect together. Until we know more about how these compounds work, please don't change your medication regimen without first discussing the matter with your physician.
Q Why might creatine be beneficial to those with other neuromuscular disorders?
A The amount of phosphocreatine in the muscles of people with some neuromuscular disorders, such as mitochondrial myopathies or inflammatory myopathies, is lower than normal. Researchers suspect that creatine supplementation in these people may improve muscle strength by bolstering the muscles' energy stores.
Q For which human neuromuscular disorders was creatine shown to improve muscle strength?
A The study reported in the March issue of Neurology examined the effects of creatine on 81 people with neuromuscular disorders, including muscular dystrophies (myotonic, Becker, limb-girdle), a metabolic myopathy (McArdle's), mitochondrial myopathies (MELAS, MNGIE and others), spinal muscle atrophy, inflammatory myopathies (polymyositis, dermatomyositis, inclusion body myositis) and congenital myopathies (multicore and central core disease).
It's important to note that the authors found an average increase in strength over the entire group of people with neuromuscular disorders in response to creatine. There didn't appear to be particular neuromuscular disorders that responded better or worse to creatine supplementation, but the sample sizes were too small to rule out greater or lesser gains for particular disorders. This was a brief (less than two weeks) study and longer studies in groups of people with the same neuromuscular disorders are necessary to address this question.
Q I want to start taking creatine -- is it safe for my disorder and how much do I take?
A There's simply not a lot of information available about the safety of creatine for those with neuromuscular disorders. For the most part, athletes haven't experienced adverse side-effects from taking creatine, although recently there have been a few reports of kidney damage linked to creatine usage. Dehydration has also been reported to be a problem while taking creatine.
Athletes generally take a "loading dose" of 20 grams of creatine a day for five or six days, then continue with a "maintenance dose" of 2 to 5 grams of creatine a day thereafter. It's not known if these dosages are safe or effective for people with neuromuscular disorders. The pilot trial reported in the March issue of Neurology showed benefits from a 10-gram "loading dose" for five days, followed by a 5-gram "maintenance dose" for five to six days. However, this study lasted less than two weeks, so the long-term effects of creatine supplementation in people with neuromuscular disorders aren't known yet.
You should also be aware that creatine, because it's categorized as a food supplement by the FDA, isn't subject to the same stringent manufacturing requirements as medications. This means that the amount and quality of creatine that you purchase may vary from one company to another or even between batches from the same company.
Because there is so little information about the safety of creatine for people with neuromuscular disorders, you're urged not to begin taking this supplement without consulting your physician.