entropyembrace wrote:PurplePotato wrote:
So consuming too much protein can cause osteoporosis, and as foods high in protein are acid-ash foods, you could say that a high acid diet causes osteoporosis. But this does not mean acidic foods like vinegar are harmful.
This is false and is addressed early in the article that Puerlife posted.
The author is pretty blunt about it in the conclusion (underlining mine):
- Alkaline diets result in a more alkaline urine pH and may result in reduced calcium in the urine, however, as seen in some recent reports, this may not reflect total calcium balance because of other buffers such as phosphate. There is no substantial evidence that this improves bone health or protects from osteoporosis.
Which I guess means that he found this to be unsubstantial:
http://jn.nutrition.org/content/128/6/1051.long. The author here is also rather blunt (underlining mine again):
- Overall, the evidence leaves little doubt that excess acidity will create a reduction in total bone substance. This is normal physiology—not pathology. This is a mechanism of Homo sapiens to protect himself against acidosis. The ability to buffer the acidosis of starvation or a high meat diet gave a survival advantage in a hunter-gatherer society. Modern peoples are now eating high protein, acid-ash diets and losing their bones.
From a cursorily look, I get the impression that the first author agrees that a high acid-ash diet causes calcium loss from bones, but that other regulatory systems will balance out this affect. The second author comes to the conclusion that such regulatory systems will not be that effective.
Sadly, even in peer-reviewed research, the truth can come down to who to believe. My guess is that one of these authors is massaging the data somehow.
Anyways, to go back to Puerlife's original question, according to this table:
http://www.precisionnutrition.com/wordp ... s-pral.pdf, coffee has a lower PRAL (potential renal acid load) than green tea. So whatever cuases the "strung out" difference, it's probably not acidity.