"Creatine: More than a sports nutrition supplement"
By Will Brink
Although creatine offers an array of benefits, most people think of it simply as a supplement that bodybuilders and other athletes use to gain strength and muscle mass. Nothing could be further from the truth.
A substantial body of research has found that creatine may have a wide variety of uses. In fact, creatine is being studied as a supplement that may help with diseases affecting the neuromuscular system, such as muscular dystrophy (MD). Recent studies suggest creatine may have therapeutic applications in aging populations for wasting syndromes, muscle atrophy, fatigue, gyrate atrophy, Parkinson's disease, Huntington's disease and other brain pathologies. Several studies have shown creatine can reduce cholesterol by up to 15% and it has been used to correct certain inborn errors of metabolism, such as in people born without the enzyme(s) responsible for making creatine. Some studies have found that creatine may increase growth hormone production.
What is creatine?
Creatine is formed in the human body from the amino acids methionine, glycine and arginine. The average person's body contains approximately 120 grams of creatine stored as creatine phosphate. Certain foods such as beef, herring and salmon, are fairly high in creatine. However, a person would have to eat pounds of these foods daily to equal what can be obtained in one teaspoon of powdered creatine.
Creatine is directly related to adenosine triphosphate (ATP). ATP is formed in the powerhouses of the cell, the mitochondria. ATP is often referred to as the "universal energy molecule" used by every cell in our bodies. An increase in oxidative stress coupled with a cell's inability to produce essential energy molecules such as ATP, is a hallmark of the aging cell and is found in many disease states. Key factors in maintaining health are the ability to: (a) prevent mitochondrial damage to DNA caused by reactive oxygen species (ROS) and (b) prevent the decline in ATP synthesis, which reduces whole body ATP levels. It would appear that maintaining antioxidant status (in particular intra-cellular glutathione) and ATP levels are essential in fighting the aging process.
It is interesting to note that many of the most promising anti-aging nutrients such as CoQ10, NAD, acetyl-l-carnitine and lipoic acid are all taken to maintain the ability of the mitochondria to produce high energy compounds such as ATP and reduce oxidative stress. The ability of a cell to do work is directly related to its ATP status and the health of the mitochondria. Heart tissue, neurons in the brain and other highly active tissues are very sensitive to this system. Even small changes in ATP can have profound effects on the tissues' ability to function properly. Of all the nutritional supplements available to us currently, creatine appears to be the most effective for maintaining or raising ATP levels.
How does creatine work?
In a nutshell, creatine works to help generate energy. When ATP loses a phosphate molecule and becomes adenosine diphosphate (ADP), it must be converted back to ATP to produce energy. Creatine is stored in the human body as creatine phosphate (CP) also called phosphocreatine. When ATP is depleted, it can be recharged by CP. That is, CP donates a phosphate molecule to the ADP, making it ATP again. An increased pool of CP means faster and greater recharging of ATP, which means more work can be performed. This is why creatine has been so successful for athletes. For short-duration explosive sports, such as sprinting, weight lifting and other anaerobic endeavors, ATP is the energy system used.
To date, research has shown that ingesting creatine can increase the total body pool of CP which leads to greater generation of energy for anaerobic forms of exercise, such as weight training and sprinting. Other effects of creatine may be increases in protein synthesis and increased cell hydration.
Creatine has had spotty results in affecting performance in endurance sports such as swimming, rowing and long distance running, with some studies showing no positive effects on performance in endurance athletes. Whether or not the failure of creatine to improve performance in endurance athletes was due to the nature of the sport or the design of the studies is still being debated.
Creatine can be found in the form of creatine monohydrate, creatine citrate, creatine phosphate, creatine-magnesium chelate and even liquid versions. However, the vast majority of research to date showing creatine to have positive effects on pathologies, muscle mass and performance used the monohydrate form. Creatine monohydrate is over 90% absorbable. What follows is a review of some of the more interesting and promising research studies with creatine.
|
