For my information I rely on research, texts, published articles by accepted experts, peer reviewed articles, lectures and discussions with and by experts in the field of Sports and related research...such as Wayne Wescott and William Kraemer.
Creatine is
synthesized (meaning assembled from parts) from the amino acids glycine, arginine and methionine in the kidneys, liver and pancreas. Free Creatine circulates in blood and in muscle tissue, where it can be converted to Phospho-Creatine with the transfer of a phosphate group or contribute a phosphate group to make ATP
ADP + PCr + H+ <---> ATP + Cr .
The body appears to have a target level for circulating Creatine, and ingestion or supplementation reduces synthesis by the body. There also appears to be a balance between intracellular Creatine (about 60%) and Creatine circulating in blood (about 40%.) Within a few days of supplementation, intracellular Cr levels reach a new equilibrium level. A much smaller fraction of this additional Creatine appears to be stored in the high-energy phosphocreatine form.
The supplemental Creatine is not
synthesized in the kidneys, liver and pancreas, it is
supplied. Then, to maintain homeostasis, some Creatine is
eliminated through the kidneys...in a volume equivalent to 1-3g/day in non supplementation or roughly equal to the amount supplemented...as creatine or creatinine.
Because Creatine is eliminated through the Kidney it has been believed there may be some risk to the kidney from supplementation, however to my knowledge there has not been any research which actually showed people with normal kidney function having any indicators of adverse kidney function. Naturally higher intake of Creatine increases kidney involvement.
Studies like, "Long-term Creatine supplementation does not significantly affect clinical markers of health in athletes." Mol Cell Biochem. 2003 Feb;244(1-2):95-104. Have found no clinical markers for long term (21-month) use in athletes. According to Dr. Kreider and coworkers, when compared to the group of football players who did not take Creatine, the football players who took Creatine actually had
fewer episodes of cramping, dehydration, muscle tightness, muscle pulls and strains, non-contact joint injuries, contact injuries, illness, number of missed practices due to injury, players lost for the season, and total injuries or missed practices.
Creatine occurs naturally in fish and meat, and is found in skeletal muscle, heart, brain, retina, testes and the uterus....etc.
When you take it away, function declines, when you return it to the diet, function returns.
Just because the human race has been eating meats doesnt mean that the body has evolved to fully utilize creatine.
But it has.
I don't know that meat is poisoned by man because there would be alot of people getting sick.
Which there are. The incidence of toxicity related illness has risen so sharply, the drug industry is struggling to make as much money off of it as they can while keeping any mention of the cause out of the mainstream press. It is not working, almost every Health show in every news format has done a special on pesticied and chemical residues building up in soils and foods, which are then stored in the fat of animals and the people who eat them.
To my knowledge, there are not a significant amount of preservatives in it.
It was a field of study for many years...I do interventions to help people recover from this stuff when the toxic load finally starts to impact them. I hate to have to be the one tell you...but the meats are colored, sprayed, irradiated, and other things they are not required to tell the consumer.
Use of antioxidants, phyto-nutrients, fiber from vegetables etc...can help the body deal with this stuff!
I eat anywhere from a half pound to a pound of 93% lean beef and it is paramount to my diet while on a strength mass gaining phase.
Yup...good thing we get more veggies, MVs, antioxidants, lots of recovery nutrition, fiber, etc!