Creatine Research Today is a free monthly online journal that collates and summarizes the latest research about Creatine, including details on supplements, side-effects, benefits, dangers, muscle growth. | |||||||
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303 °C (decomp.) Y (what is this?) (verify)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references Creatine is a nitrogenous organic acid that occurs naturally in vertebrates and helps to supply energy to muscle. Creatine was identified in 1832 when Michel Eugène Chevreul discovered it as a component of skeletal muscle, which he later named creatine after the Greek word for flesh, Kreas. BiosynthesisCreatine is naturally produced in the human body from amino acids primarily in the kidney and liver. It is transported in the blood for use by muscles. Approximately 95% of the human body's total creatine is located in skeletal muscle.The rest is located in the brain or heart.[1] [2] Creatine is not an essential nutrient as it is manufactured in the human body from L-arginine, glycine, and L-methionine. [3] In humans and animals, approximately half of stored creatine originates from food (mainly from fresh meat). Since vegetables do not contain creatine, vegetarians show lower levels of muscle creatine. With the help of creatine supplementation vegetarians can compensate for this loss.[4] The pathway for the synthesis of creatineArg - Arginine; GATM - Glycine amidinotransferase; GAMT - Guanidinoacetate N-methyltransferase; Gly - Glycine; Met - Methionine; SAH - S-adenosyl homocysteine; SAM - S-adenosyl methionine. The color scheme is as follows:enzymes, coenzymes and the Met part, substrate names, the Gly part, the Arg part The enzyme GATM (L-arginine:glycine amidinotransferase (AGAT), EC 2.1.4.1) is a mitochondrial enzyme responsible for catalyzing the first rate-limiting step of creatine biosynthesis, and is primarily expressed in the kidneys and pancreas.[5] The second enzyme in the pathway (GAMT, guanidinoacetate N-methyltransferase, EC:2.1.1.2) is primarily expressed in the liver and pancreas[1]. Genetic deficiencies in the creatine biosynthetic pathway lead to various severe neurological defects.[6] Health EffectsAllergiesCreatine has been associated with asthmatic symptoms. People should avoid creatine if they have known allergies to this supplement. Signs of allergy may include rash, itching, or shortness of breath. Side effects and warningsSome individuals may experience gastrointestinal symptoms, including loss of appetite, stomach discomfort, diarrhea, or nausea. This primarely only when using the older forms of creatine. This problem is not an issue if you take one of the newly developed forms of creatine(see Newly Developed Forms). Creatine may cause muscle cramps, leading to discomfort. Weight gain and increased body mass may occur. This is a result of the muscles absorbing more water. Drinking a little more water than usual is recommended while taking this supplement. It is possible to experience kidney damage while taking this supplement if you have kidney disease or have had a transplant. It is highly discouraged for transplant patients to take creatine. There is less concern today than there used to be about possible kidney damage from creatine. Patients with kidney disease should avoid use of this supplement. Similarly, liver function may be altered, and caution is advised in those with underlying liver disease. In theory, creatine may alter the activities of insulin. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare professional, and medication adjustments may be necessary. Newly Developed FormsThe original form of creatine on the market was called creatine monohydrate. Since then, scientists have formed new more effective versions of this supplement. These new forms of creatine do not have the gastrointestinal symptoms that monohydrate did. Citrate, Phosphate, Malate, Tartrate, and Alpha-Ketoglutarate are all examples of these new forms.
The other new forms showed similar results from their studies except for Tartrate. Creatine Tartrate has been known to cause muscle cramps and severe headaches. It is recomended to chose another form due to it's side effects. Today creatine users have to worry about very few if any side effects. Although they are much improved, it is still discouraged for a person with kidney or liver problems to take these new forms of creatine. Also if you have diabetes you should not take this. Pregnancy and breastfeedingCreatine cannot be recommended during pregnancy or breastfeeding due to a lack of very much scientific information. Pasteurized cow's milk contains higher levels of creatine than human milk.[7] Treatment of diseasesCreatine has been demonstrated to cause modest increases in strength in people with a variety of neuromuscular disorders.[8] Creatine supplementation has been, and continues to be, investigated as a possible therapeutic approach for the treatment of muscular, neuromuscular, neurological and neurodegenerative diseases (arthritis, congestive heart failure, Parkinson's disease, disuse atrophy, gyrate atrophy, McArdle's disease, Huntington's disease, miscellaneous neuromuscular diseases, mitochondrial diseases, muscular dystrophy, and neuroprotection).[citation needed] A study demonstrated that creatine is 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). The neuroprotective effects of creatine in the mouse model of ALS may be 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.[9] A similarly promising result has been obtained in prolonging the life of transgenic mice affected by Huntington's disease. Creatine treatment lessened brain atrophy and the formation of intranuclear inclusions, attenuated reductions in striatal N-acetylaspartate, and delayed the development of hyperglycemia.[10] Given the results in animal studies, creatine is just beginning to be explored in several multi-center clinical studies in the USA and elsewhere.[citation needed]. Creatine supplements and athleticsMain article: Creatine supplementsCreatine supplements are sometimes used by athletes, bodybuilders, and others who wish to gain muscle mass. Cognitive abilityA placebo-controlled double-blind experiment found that vegetarians who took 5 grams of creatine per day for six weeks showed a significant improvement on two separate tests of fluid intelligence, Raven's Progressive Matrices and the backward digit span test from the WAIS. The treatment group was able to repeat back longer sequences of numbers from memory and had higher overall IQ scores than the control group. The researchers concluded that "supplementation with creatine significantly increased intelligence compared with placebo."[11] A subsequent study found that creatine supplements improved cognitive ability in the elderly.[12] A study on young adults (0.03 g/kg/day for six weeks; only 2 g/day for 150lb individual) failed however to find any improvements.[13] See also
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