As Designed by Nature the Human Body Functions Best in a Slightly Alkaline State
“The body is alkaline by design, but acidic by function.” So noted Nobel Laureate Albert Szent-Györgyi, the scientist who discovered vitamin C.
This often quoted one-liner refers to the fact that most of our body’s physiological functions require a slightly alkaline environment for optimum functioning. Yet at the same time, our metabolic processes produce enormous quantities of acid. Actually, as a by-product of our metabolism we produce some 70,000 mmol of protons (H+ or acid) each day. We generate a lot of acid, yet our chemistry needs to be alkaline to survive.
We generate acids, but they do not generally accumulate—if they did we would die.
Within nature’s great design, few of these internally generated acids actually accumulate in the body. The control of neutralization of acids is attributable to the body’s elegant buffering systems, and to the fact that acids are generally formed with a partner that aids in their removal. In fact, while an enormous number of H+ ions are produced, most of them are balanced and neutralized by bicarbonate production. Overall, in health, the amount of free H+ or free acid within the body is tiny. In certain disease states, such as diabetic ketoacidosis, acids do accumulate and this can be life-threatening.
How acids can accumulate in a healthy person
Dietary imbalance is the means by which acids can accumulate in a healthy person. As it happens, most foods we eat are either acid forming or alkaline forming after metabolism. Foods like fruits, vegetables, root crops, nuts, and seeds are alkaline forming. Proteins and grains with their sulfur containing amino acids and our many processed and denatured foods are acid forming. Excessive intake of long-chain fatty acids is also acid forming.
Historically through human evolution we consumed diets high in alkaline-forming foods and in fact, University of California pH researcher Dr. Anthony Sebastian has calculated that the vast majority of our ancestral diets were alkaline forming due to the high intake of potassium from vegetables, fruits, nuts, and seeds.
If we consume an excess of acid-forming foods that are not compensated for by a high intake of alkaline-forming foods, metabolic acids can accumulate in the body. As we will detail, these acids, although smaller in number, can have a large impact on physiological functioning.
What is the biological cost of low-grade chronic metabolic acidosis?
When diet leads to a buildup of metabolic acids, the body has to rely on various protective mechanisms to neutralize the acids. If these pH-balancing mechanisms are called upon over a long period of time, many of the body’s systems begin to become compromised. Ultimately, this sets the stage for disease.
Even small changes in pH can have a big physiological impact. For example, all the chemical reactions necessary for proper body function are initiated by enzymes, and enzymes work in a narrow pH range.
If pH levels change for any length of time, neither the enzymes nor the chemical reactions they initiate can function properly. Biological systems might not fail completely, but the body becomes weakened and prone to disease. That’s why it’s so important to establish a dietary balance with an alkaline diet plan that will not place an undue acid burden on the body.
Cordain, L., S. B. Eaton, A. Sebastian, N. Mann, S. Lindeberg, B. A. Watkins, J. H. O’Keefe, and J. Brand-Miller. 2005. Origins and evolution of the Western diet: Health implications for the 21st century. American Journal of Clinical Nutrition 81:341–354.