John M Berardi wrote:
John M Berardi wrote:
Theories about the effects of acidic and basic foods in the body have been mentioned in a few other posts and featured in Berardi's "Covering You Acids and Bases." I don't know a tremendous amount about these theories, but I have some thoughts regarding their validity. I'm wondering if the acidity or basicity of food matters at all. Let me know what you think.
When food reaches the stomach, gastrin stimulates the secretion of hydrocholic acid, which lowers the pH of the stomach to about 1.5-1.7. At this low acidity, proteins denature, enabling stomach proteases to begin breaking apart peptide bonds. Since enzymes function at specific pH levels, stomach proteases must require the 1.5-1.7 pH range. Therefore, if stomach function is normal, hydrochloric acid secretion would adjust according to foods eaten so that this pH is obtained. Otherwise, protein digestion in the stomach would be significantly compromised.
When chyme reaches the small intestine, the hormone secretin from the walls of the intestine signals the pancreas to release bicarbonate Bicarbonate alters the pH of the food again, by raising the pH to approximately neutral. Again, since enzymes function at specific pH levels, this approximately neutral pH must be necessary for intestinal digestive enzymes to work.
Thus, the pH of the food is altered before it leaves our digestive tracts. Now, the pH of individual nutrients when they reach the bloodstream is likely what this theory
is all about. However, our blood contains buffers that constantly regulate pH so that our blood remains close to neutral.
If these buffers are in short supply, I would think it would be the cause of a mineral deficiecy or metabolic disorder, a long-term effect rather than the consequence of an individual meal. Also, as Berardi said, proteins have their own system of regulating pH (production then subsequent excretion of urea). So, with all these systems in place, is the net acid/base content of a meal really important?
Let me know what you think.
Your thinking is rock solid except one point.
It's NOT the acid/base content of a specific food OUTSIDE the body that matters. It's the PRAL (potential renal acid load) of the food that matters.
The PRAL is not a theoretical construct - it's a measurable, testable thing - it's the acid (or alkaline) load the kidneys see.
So, you can see, that although the PH values of the food itself are altered during the digestive/absorptive process, it's not the food we're measuring. It's the result of eating the food - measured by the PRAL.
That's why oranges are acidic outside the body but basic after digestion/absorption.
(That's also why the measures of food acidity outside the body are useless).
Is this clear?
Also, one more important point, these ideas are nothing new. They are WELL validated in the scientific literature - take a peek through medline to learn more about them.
This stuff is critical, especially as we age.