For your body to function, your blood, saliva, urine and the fluids in and around your cells must maintain a proper balance between acidity and alkalinity, otherwise known as pH balance. The pH of healthy, oxygen-rich blood is between 7.365 and 7.45, or slightly alkaline. The food you eat affects this pH balance, either by helping your body maintain its natural state of alkalinity or temporarily shifting it slightly toward acidity, according to a review in the 2012 issue of the "Journal of Environmental and Public Health."
Cow’s milk, like the majority of dairy and animal products, is an acid-forming food. As with all foods, the pH nature of milk in the body is determined by the end products resulting from metabolizing it, not by the pH of the milk itself. A 3.5-ounce serving of either whole or skim milk is only slightly acid-forming, placing an acid load on the kidneys of 0.7 milliequivalents, or 1/1,000 of an equivalent. Whole, evaporated milk is only slightly more acid-forming, giving the kidneys an acid load of 1.1 milliequivalents. By comparison, a 3.5-ounce serving of plain, processed cheese made from cow’s milk creates a potential acid load of 28.7 milliequivalents, and is much more acid-forming than milk.
Acid-Forming Food Effects
The main effect of eating a diet high in acid-forming foods is twofold: it depletes your body’s alkali reserves and promotes acidosis, or acid buildup. Your body has a complex series of physiological mechanisms to neutralize and then eliminate excess acid buildup, primarily through the kidneys, lungs and skin. It utilizes its reserved alkalizing compounds to buffer the acids so they don’t damage delicate tissues as they’re eliminated. Because your kidneys can only eliminate a certain amount of solid acids each day, acidosis occurs when you over-consume acid-forming foods. Acidosis disrupts normal cell functioning and can set the stage for a variety of health issues, including osteoporosis, gout and rheumatoid arthritis.
To replenish your body’s alkaline reserves and sustain healthy pH levels, “Alkalize or Die” author Dr. Theodore Baroody recommends following the “80/20” rule, which calls for consuming a diet that’s 80 percent alkaline-forming foods and 20 percent acid-forming. Most vegetables and fruits are alkaline-forming — exceptions include skinless potatoes, blueberries, cranberries, plums and prunes, all of which are slightly acid-forming. Amaranth, millet and quinoa are alkaline-forming grains, but most other grains, including brown rice and whole wheat, are acid-forming. Many legumes, some nuts and seeds and most herbs are alkaline-forming foods.
Not all types of milk are acid-forming. While pasteurized goat’s milk falls into the slightly acidic category alongside cow’s milk, raw goat’s milk is slightly alkaline-forming. Almond milk is also alkaline-forming and provides another alternative to cow’s milk. According to Dr. Baroody, soy milk has a neutral effect on the body’s pH levels — it’s neither alkaline-forming nor acid-forming. Unsweetened fruit juice, vegetable juice, lemon water, green tea and herbal tea made from leaves or roots are other alkaline-forming beverage options.