by Alan C. Logan
SCIENTISTS REFER TO our acid-alkaline states on a numerical scale called potential of hydrogen, or pH. The scale runs from 1 – 14, with one being most acidic and 14 most alkaline. The pH of our bodily systems is tightly regulated, operating near the middle of the pH scale. In the blood stream, any deviation away from a near-neutral pH may compromise our very survival.
In recent years, the connection between the frequent consumption of acid-forming foods and various aspects of human health, has been the subject of intense scientific scrutiny. Scientists refer to acid and alkaline “forming” foods, meaning the potential a food or beverage has in tipping the scale toward acidity or alkalinity inside the body. Although the determination of acidity or alkalinity of a food or beverage is somewhat complex, it is dictated to a large degree by the amount of potassium and bicarbonates (alkaline) and protein (acidic). Sometimes foods or beverages we might consider to be “acidic,” like oranges or tomatoes, are actually quite alkaline in the body due to the presence of minerals and bicarbonates. In North America we have developed a great fondness for acid-forming foods, particularly animal meats, cheeses, grains, soft drinks and processed foods.
We have excluded fruits and vegetables; only 29% of adults and 13% of children consume the minimum daily-recommended five servings. Ffruits and vegetables are incredibly rich in alkaline minerals and bicarbonates. Clearly, the scale is tipped in favor of acidic foods, with a dietary acid load some three times higher than the hunter-gatherer diets of traditional, isolated communities. This increased dietary acid load is not without consequence to human health.
Researchers have known for more than a decade that a diet high in acidic foods and beverages, particularly in the absence of fruits and vegetables, is associated with increased osteoporosis and fracture risk. Since blood pH must be kept neutral for our survival, calcium and magnesium are removed from the bone to buffer, or neutralize a continuously acidic dietary influence – calcium and magnesium are subsequently lost in urine. Over time this leads to an appreciable loss of minerals from the bone matrix. Scientists have also shown that the cells that make bone, the osteoblasts, are less active in acidic environments. Even a modest change to a more alkaline diet has been associated with a 50% reduction in fracture risk.
More recent studies have linked an acidic diet to increased body weight, increased waist circumference and various markers of cardiovascular disease, including elevated cholesterol and hypertension. More alkaline urine is associated with a greater percentage of lean body mass. Oof course it would be tempting to write off the health-promoting influence of alkaline fruits and vegetables to the fact that such diets are subsequently greater in antioxidants, fiber, and overall, less calories. Yet, in 2003 Swiss researchers discovered an important physiological change induced by an acidic, fast-food-type diet – a change that has enormous implications to human health. They found that nine days of an acidic diet significantly elevated the stress hormone cortisol. When the researchers neutralized the Western diet with bicarbonate supplements, the cortisol levels dropped down to normal. Since cortisol increases the propensity to gain abdominal fat, promotes inflammation and oxidative stress, disturbs immune function and mood states, the research makes pH an important consideration in human health.