“We need to rediscover the foods that brought our Paleolithic ancestors vibrant health, lean bodies, and freedom from chronic disease. The foods that agreed with their genetic blueprints are the same foods that agree nicely with our genetic blueprints.”
Keep an eye on the pH of the foods you eat; the repercussions could affect your entire body.
First, a quick refresher on pH from high school chemistry: the acidity or alkalinity of any solution is determined by how much hydrogen (H+) and hydroxide (OH-) ions are within the solvent and is expressed as pH, meaning “power of Hydrogen [or ‘potential of hydrogen’].” The pH of a solution is a mathematical calculation based on a scale from 0–14, where 7 is neutral. This is the pH of distilled water, where the relative concentrations of H+ and OH- are equal. For every unit below pH 7.0, the concentration of H+ increases by a factor of 10. Those kinds of solutions are acidic. For every unit above 7.0, the concentration of OH- is increased similarly. Those kinds of solutions are alkaline.
Diet and pH
The foods, including liquids, that you consume every day, have major effects on the acid/alkaline balance of the body. Unprocessed plant fiber and fruits are more alkalizing, while meat, dairy, and cereals are more acid-yielding. A lemon, though very acidic, will actually reduce the body’s acidic load once its mineral contents are absorbed into the body’s fluids. This is because the predominant minerals within the lemon (i.e. the electrically positive cations of calcium, potassium, sodium, and magnesium) have an alkalizing (acid-reducing) effect on the body. They do this by forming mineral hydroxides and carbonates in our cells, which act like molecular sponges to “suck up” excess acidity.
Our ancient human ancestors’ early diets consisted of a plant-to-animal ratio of close to 1:1, with fish and shellfish comprising much of the animal component.1 However, that was thousands of years ago. Recently, our diets have become much more heavily dependent on foods with high acidic loads, and our bodies haven’t been able to adjust. There are five major groups of foods that are acid-producing: grains, legumes, dairy—especially cheeses—salt, and red meat. The first four were rarely, if ever, eaten by our Paleolithic ancestors. In addition, the large amounts of animal foods the hunter-gatherers ate were buffered by even larger (by the standards of modern diets) amounts of alkaline fruits and vegetables.2
Health Effects of Acid/Alkaline Balance
It is critical that the pH of human blood stay as close as possible to 7.365, or slightly alkaline. If it drops below 7.0 (acidemia) or rises above 7.8 (alkalemia), coma and death can quickly follow. Consequently, the human body does everything in its power to ensure that the pH of its tissues remains within stringent confines.
For example, to preserve pH balance under conditions of chronic acid load, the body must continually draw on its alkaline reserves by releasing calcium, potassium, and magnesium from the bone matrix to neutralize excess acid. In addition, the body begins to break down muscle protein in order to release the amino acid glutamine. In turn, glutamine is converted to glutamic acid (glutamate) by the liver and, in doing so, binds with excess hydrogen ions to generate ammonia (NH4+). The ammonia is then excreted in the urine, along with chloride (Cl-) ions that are needed to balance the electrochemical charge.3,4
pH and Bone Tissue
Basically, your body will use the minerals from your bones to reduce the acidity in your tissues. What this means is a loss of calcium and other minerals from the bones (potentially resulting in osteopenia which can lead to osteoporosis later in life) and progressive muscle wasting if your diet is too acidic.
It begins with the release of the alkaline minerals sodium and potassium from the bone surface, which the blood uses as its first line of defense against excess acid. If this action fails to restore pH balance, the body then stimulates osteoclast (bone-destroying cells) activity and shuts down osteoblast (bone-forming cells) activity. This precipitates the release of calcium and the carbonate/phosphate buffers from the bone mineral matrix and the increase of calcium (hypercalciuria) in the blood.5
Bone resorption by osteoclasts is absolutely dependent on extracellular acidification; these cells are inactive at alkaline pH levels (above 7.3) and show maximum stimulation at a pH of about 6.9. Resorption is most sensitive to changes in acidity at a pH of about 7.1 (close to the interstitial pH in bone). This cell-mediated response is likely effected through the release of the stress-related hormone cortisol, high levels of which are known to concurrently deplete muscle protein and accelerate mineral loss (a likely reason why prolonged stress, which raises blood cortisol levels, will accelerate bone loss).6
In addition to facilitating osteoporosis, an acid-promoting diet initiates a broad cascade of biochemical and physiological changes to our inner terrain that appear to set us up for cancer. These include: chronic oxidative stress, enhanced catabolism (muscle wasting and destruction of skeletal reserves), elevation of insulin and cortisol, systemic inflammation, obesity, and impaired immunity. Each of these aberrations is known singularly to be involved with the genesis of the cancer process. Just imagine the implications when they are all pulling on the same rope.
1 SB. Eaton, MJ. Konner, L. Cordain, “Diet-dependent Acid Load, Paleolithic Nutrition and Evolutionary Health Promotion,” American Journal of Clinical Nutrition 91, no. 2 (2010): 295-7.
2 Cordain, L. The Paleo Diet (New York: John Wiley and Sons 2002) P. 86.
3 Frassetto L, Morris RC, Jr., Sebastian A., “Potassium bicarbonate reduces urinary nitrogen excretion in postmenopausal women,” Journal of Clinical Endocrinology & Metabolism 82, no. 1 (1997): 254-9.
4 Welbourne TC, Joshi S., “Enteral glutamine spares endogenous glutamine in chronic acidosis,” J Parenter Enteral Nutr 18, no. 3 (1994): 243-7.
5 Bushinsky DA., “Acid-base imbalance and the skeleton,” Eur J Nutr 40, no. 5 (2001): 238-44.
6 Maurer M, Riesen W, Muser J, Hulter HN, Krapf R. “Neutralization of Western diet inhibits bone resorption independently of K intake and reduces cortisol secretion in humans,” Am J Physiol Renal Physiol 284, no. 1 (2003): F32-F40.