The cells in our stomach wall produce stomach acid on an instantly-as-needed basis. The ingredients in the stomach cell that make hydrochloric acid (HCL) are carbon dioxide (CO2), water (H2O), and sodium chloride (NaCl) or potassium chloride (KCl).
NaCl + H2O + CO2 = HCl + NaHCO3, or
KCl + H2O + CO2 = HCl + KHCO3
As we can see, the byproduct of making hydrochloric acid is sodium bicarbonate (NaHCO3) or potassium bicarbonate (KHCO3), which goes into the blood stream. These bicarbonates are the alkaline buffers that neutralize excess acids in the blood. They dissolve solid acid wastes into liquid form. As they neutralize the solid acidic wastes, extra carbon dioxide is released and discharged through the lungs. As our body gets old, these alkaline buffers get low. This phenomenon is called acidosis. This is a natural occurrence as our body accumulates more acidic waste products. There is, therefore, a relationship between the aging process and the accumulation of acids.