Why Acid Is Bad

Every cell of the body functions optimally within a certain pH range (pH is a measure of the acidity or alkalinity of the body). In different cells, this optimal range is different, however, the net pH of the body has to remain tightly regulated. One common problem with most industrialized societies is that our diets produce what's called a "low grade chronic metabolic acidosis." In other words, the PRAL of our diets is high and this means that we're chronically in a state of high acidity. While there are a number of disease states that induce severe metabolic acidosis, we're talking a sub-clinical rise in acidity here. Therefore, your doc probably won't notice the problem. But that doesn't mean that you're in the clear. Your cells will recognize the problem.

So what's wrong with this low-grade chronic metabolic acidosis? Well, since the body must, at all costs, operate at a stable pH, any dietary acid load has to be neutralized by one of a number of homeostatic base-producing mechanisms. So, although the pH of the body is maintained and your doctor visits turn out fine, many cells of the body will suffer. Here are some of the most severe consequences of your body's attempt to maintain a constant pH in the face of an acidic environment:

       Hypercalciuria (high concentrations of calcium in the urine). Since calcium is a strong base and bone contains the body's largest calcium store, metabolic acidosis causes a release in calcium from bone. As a result, osteoclastic (bone degrading) activity increases and osteoblastic (bone building) activity decreases. The net result of these changes is that bone is lost in order to neutralize the acidic environment of the body. The calcium that was stored in the bone is then lost in the urine along with the acid it was mobilized to neutralize. This creates a negative calcium balance (more calcium is lost from the body than is consumed) and bones get weak. (2,3,4,6)

       Negative nitrogen balance (high concentrations of nitrogen in urine). Glutamine is responsible for binding hydrogen ions to form ammonium. Since hydrogen ions are acidic, glutamine acts much like calcium to neutralize the body's acidosis. Since skeletal muscle contains the body's largest glutamine store, metabolic acidosis causes muscle breakdown to liberate glutamine from the muscle. The Amino Acids from this muscle breakdown are then excreted, causing a net loss of muscle protein. (2,7)

In addition to bone and muscle loss, other consequences of acidosis include:

       Decreased IGF1 activity (4)

       GH resistance (4)

       Mild hypothyroidism (4)

       Hypercortisolemia (4,5)

Interestingly, low-grade metabolic acidosis seems to worsen with age. Many have speculated that this is due to an age-related decline in kidney function (and acid excretion). Of course, osteoporosis and muscle wasting are unfortunate consequences of aging. While it's too early to tell, perhaps some of the bone and muscle loss evident as individuals get older is a result of diet-induced acidosis. This means that employing a few simple acid-base strategies may help slow osteoporosis and sarcopoenia.