Source? There are many sources that show that pH in urine and saliva increases when people drink alkaline water.

Of course urine would, its the result of kidneys eliminating the acid brought to them by the plasma buffer system. But blood and body Ph don't change.

The body is incredibly complex so I'm not saying this is conclusive but here's a source plus a lot of explanation with numerous experiments.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3828631/

Another thing: Calcium strongly associates with acid.

And there's no evidence of osteoporosis or bone leaching with high acid diets.

You type "pH" as "Ph" so are you sure you know what you are talking about or are you just repeating some evidence you found after a few seconds of searching?

I've spent many hours researching this topic, and the paper is incorrect for multiple reasons and one of which being that it is using a straw man argument.

> This hypothesis posits that foods associated with an increased urinary acid excretion are deleterious for the skeleton, leading to osteoporosis and enhanced fragility fracture risk.

That the second part of this hypothesis could be true is actually super easy to prove from a purely chemical perspective. When the pH of the blood drops, cells such as bones and muscle cells will release buffering ions such as phosphate from bone and proteins from muscle cells. As long as the minerals from the bones are not replaced, the bones will weaken.

The straw man in this claim is that the pH discussion usually talks about what foods change the body's overall pH balance in what direction; not just the urine.

Yep, homeostasis