Creatine

Creatine is a nitrogen containing carboxylic acid found in meat that plays a role in energy(ATP) regulation within human cells. Within cells including muscle cells, phosphocreatine undergoes a reversible reaction with ADP to form ATP and creatine. During times when muscle cells have exhausted all of their energy from glycogen stores, this phosphocreatine allows an alternative energy production pathway to produce ATP. When energy is sufficient, the reaction goes in the opposite direction favoring the formation of phosphocreatine and ADP. This is why creatine is sometimes referred to as an "energy buffer" of the cell.

The human body can synthesize creatine from the amino acids glycine, methionine and arginine. Most creatine is stored within muscle cells. It can also be consumed from meat and fish.

Benefits on the  Brain

Creatine has shown benefits in brain function. It has demonstrated an ability to decrease glutamate release, which could have a protective effect on brain cells because excessive glutamate release is associated with neuronal damage. There is also a protein within cells called mitochondrial creatine kinase which acts to stabilize cell membranes, preventing the passage of unwanted substances. Some studies have shown increases in attention and intelligence test scores in groups that consumed creatine. For these reasons, there are clinical trials underway exploring the possible benefits of creatine for treating Huntington's Disease.

Muscle Training Benefits

Creatine has shown benefits of muscle strength and endurance. In muscle cells, it has shown an uptake of water in the cells(this could cause dehydration, therefore it is recommended to stay well hydrated if using creatine), increase in muscle fiber size, and greater increases in strength over time if used with strength training. Creatine supplements are intended to increase the phosphocreatine levels within muscle cells. Some studies have shown that taking creatine with carbohydrates can increase the amount of creatine that gets taken into the muscle cells.

Safety

There is a lack research and conclusive information about the long term adverse effects of creatine supplementation. There have been a few case studies reporting kidney dysfunction with supplementation. Most studies have demonstrated that is is likely safe for short term use. Creatine is a natural substance that is already within the human body and therefore it is possible that, if there are harmful effects, it will be seen with very high doses or for very long periods of time, which could change the way the body makes and transports its natural creatine.

Key References