Understanding What It Means By Our Bodies Being Acidic Or Alkaline.
What's the dangers of having an acidic body?
The concepts of acidity and alkalinity have been thrown about quite frequently in today’s world.
For example, we know that foods containing acids tend to taste sour - which is particularly true for acidic fruits such as lemons and limes.
Alkalis tend to leave a bitter taste in one’s mouth - if you have accidentally tasted soap before, for instance, you’d find that it tastes bitter (but please don’t try licking a soap bar just to verify that what I say is correct!)
But what really constitutes an acid and an alkali?
We’d be looking at the pH scale, which refers to the “power of hydrogen” scale. Mathematically, we’re taking the negative log of the concentration of the hydrogen ions in a solution to determine its pH:
pH = - log [H + ]
A pH of 1 in a solution indicates that the hydrogen ion concentration in that solution is at 0.1 moles per litre, whereas a pH of 7 in a solution indicates that the hydrogen ion concentration in that solution is at 0.0000001 moles per litre. For every unit that the pH level decreases by, the hydrogen concentration increases 10 times.
The lower the pH value of a solution is, the higher its hydrogen ion concentration will be.
Hence, to debunk one common health myth out there: We don’t get acidic bodies as a result of eating highly acidic foods. Heck, can you imagine what vinegar can do to our blood pH if it got into direct contact with our blood? Vinegar, at pH 2.5, would contain so many more hydrogen ions than our blood would contain.
As you can see, the ramifications are pretty severe, especially with regards to the acid base chemistry - hence the vinegar that we consume won’t ever get into direct contact with our blood (even stomach acid doesn’t get into direct contact with our blood).
The pH of an alkali typically ranges from 7-14, and most tend to be cleaning agents such as detergents and soaps.
A pH value of 7 is determined to be “neutral”, which does make our blood very slightly alkaline at a pH of 7.35 (hydrogen ion concentration 0.000000446 moles per litre) to 7.45 (hydrogen ion concentration 0.0000000354 moles per litre).
We’d basically have very little leeway for acidity errors in our blood with such a tightly regulated system. Getting into a state of acidosis (too much acidity) or alkalosis (too much alkalinity) would mean that there is something wrong with our internal pH controllers.
What governs the acidity of the body, then?
In our stomach, we’d be looking at the activity of the carbonic anhydrase (CA) enzyme.
In our digestive system, CA is responsible for the production of gastric acid by the parietal cells:
HCl is produced by the parietal cells of the stomach. To begin with, water (H2O) and carbon dioxide (CO2) combine within the parietal cell cytoplasm to produce carbonic acid (H2CO3), catalysed by carbonic anhydrase. Carbonic acid then spontaneously dissociates into a hydrogen ion (H+) and a bicarbonate ion (HCO3–).
The hydrogen ion that was formed is transported into the stomach lumen via the H+– K+ ATPase. This channel uses ATP energy to exchange potassium ions in the stomach with hydrogen ions in the parietal cell.
The bicarbonate ion is transported out of the cell into the blood via a transporter protein called anion exchanger which transports the bicarbonate ion out the cell in exchange for a chloride ion (Cl–). This chloride ion is then transported into the stomach lumen via a chloride channel.
This results in both hydrogen and chloride ions being present within the stomach lumen. Their opposing charges leads to them associating with each other to form hydrochloric acid (HCl).
That’s how our stomach produces those acidic gastric juices!
Before the digested food exits our stomach into our intestines, bicarbonate ions are added back into that mix to bring the pH up to a more tolerable level for the intestines to do their work in absorbing those nutrients.
Similarly, CA in the kidneys is thought to maintain the acid/base equilibrium in our blood based on controlling bicarbonate resorption from our urine before excretion, with the mechanism outlined here:
In the proximal convoluted tubule (PCT) cell, carbonic anhydrase (not shown) generates bicarbonate and hydrogen from water and carbon dioxide. Sodium in filtered urine is resorbed in exchange (with a sodium/hydrogen cotransporter) for the hydrogen produced from carbonic anhydrase. The excreted hydrogen then combines with filtered bicarbonate. This forms the weak acid, carbonic acid, which then disassociates to produce water and carbon dioxide in the urine (tubular lumen). The bicarbonate created by carbonic anhydrase is transported, with the resorbed sodium, into the blood via a basolateral (blood side) sodium/bicarbonate cotransporter. Thus, through carbonic anhydrase and sodium absorption, the proximal tubules “reclaim” the filtered bicarbonate (or, in reality, generate new bicarbonate which replaces that lost in the urine, so there is no net gain of bicarbonate).
Meaning that the CA enzyme plays a significant role in maintaining the pH of our bodies. We need a significantly acidic stomach to allow the various digestive enzymes to function at their optimal activity, and we also do need to regulate our urine flow to maintain the pH of our blood at a proper level.
Of course, this all depends on the CA enzyme being able to function properly in its working environment, doesn’t it?
The issue that diabetics have with ketoacidosis
Unfortunately, it isn’t just the CA enzyme that regulates the acidity of the body.
Type 1 diabetics are also highly susceptible to a condition known as diabetic ketoacidosis. In that situation, their inability to produce sufficient insulin for the cells in their bodies to take in glucose for energy generation purposes would force their cells to turn towards breaking down fats into ketones at an uncontrolled rate, and unfortunately those ketones do end up being acidic.
While the energy generation is similar to the ketosis that a ketogenic diet provides, we do have to understand that the ketogenic diet provides a more regulated approach towards the breaking down of these fats into ketones, hence acidosis isn’t a real problem with a well regulated keto diet.
At the end of the day…
We do need to understand that the acidity in our bodies is tightly regulated, and not without reason.
The enzymes and cells in our body all operate optimally at an extremely narrow pH range, and it would be to the best interest of our body to be able to regulate it internally that way.
When significant and irreversible changes start occurring to the acidity in our blood, there would be indications that something is seriously wrong somewhere - and that’s when it would be necessary to seek the diagnosis of a medical professional, not to look at eating foods that are “less acidic”!
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