Originally posted by Twin Peak
I'd love to hear an articulate reason, supported by fact, on why "too much protein is bad."
And let me underscore the word bad. That phrase was used several times herein.
I can articulate several arguments about why it is not "optimal" -- but that is not what has been said.
And if the answer is "protein is stored in your bones" please provide authority to this.
Once again it depends, unfortunately, when it comes to the human body, there is never a simple dogmatic answer.
For instance, there is a clear association between high protein diets and development of kidney stones (especially calcium oxalate and uric acid stones.) and gout. So if you are prone to kidney stones or gout, then a higher protein intake is definately not advisable.
The issue with kidneys is less clear. Once again, I think you have to have an underlying kidney disorder to begin with before it is much of a problem. The problem is that no good prospective or retrospective data exists for those with
healthy kidneys. (In diseased kidneys, there is a clear prevention or delay towards dialysis in those with impaired kidney function who embark on low protein diets.)
As for osteoperosis, does high protein diet cause osteoperosis? Prospective clinical trials are underway (unfortuneatly using sedentary people on Atkins) so we don't know yet.
The studies out now say yes....and no.
The following link quotes studies that say HIGH-PROTEIN DIET CAUSES OSTEOPOROSIS
http://www.drmirkin.com/archive/7130.html
Then, look at this other study that says it actually helps build bone
http://my.webmd.com/content/article/17/1671_53109?src=Inktomi&condition=Food_and_Nutrition
March 25, 2002 -- Eating more protein could help your body absorb calcium, possibly putting a halt to bone-thinning osteoporosis, says a new study
What's the difference? The answer...the study technique and different patient population. The latter link shows that high protein diets can actually build bone if people are supplementing correctly with enough calcium and minerals and it was a prospective trial that enlisted study subjects and followed them for three years making sure certain variables were constant and consistent. The former link just looks at epidimiological and retrospective data that cannot contol for "confounding" variables (ie: unknown variables that may affect the conclusion such as activity level and calcium supplementation, soda pop ingestion etc.) Also, one was just a urine study that did measure higher rates of calcium excretion in the urine but you cannnot extrapolate that to osteoperosis directly and so on.
My theory is it does cause osteoperosis in those who are sedentary and not supplementing correctly but will increase bone density in those who are active and supplement correctly. Here is my rational.
The protein ingested is broken down to amino acids in the body. The excess of the amino acids that are formed and not needed by the body has to be excreted by the kidneys. Each molecule of an amino acid must be neutralized before the kidneys can excrete it. Our body calls on calcium to handle the job. But the calcium gets excreted in the urine, along with the amino acids. (That's why the doubling of risk of kidney stone formation in those susceptible.) This process drains the supply of calcium in our bloodstream, so the body has to tap the stores in bones.
Now, an athlete or body builder is going to have less excess amino acids and their bodies will be using up the "excess" and building up muscle rather than pissing it out and sequestering calcium from the bones....(that's why the supplementation is important.) In fact, Atkins realized this and tells his dieters to increase the amount of calcium intake.
So the answer, is high protein diet bad or good for you? It all depends. I know, what a cop out
.
But good observation on the protein though 