Is the Body Alkaline or Acid?
There is a lot of confusion regarding pH and the human body. I recently posted about digestion and many were surprised that the normal healthy pH range of the stomach is very acid which means more acid = better digestion. People make generalizations about making the body more alkaline or eating an alkaline diet but are these claims matched with biochemistry or fact?
Nope.
Well, not exactly. If we clean up the statements a little and define the physiological relationships then it will make more sense.
pH Scale
pH is a scale of acidity from 0 to 14 based on the concentration of protons (H+) in a solution.The lower the number the more acid and the higher the number the more alkaline. Different systems of the body operate optimally in different pH ranges. For example, when the stomach is functioning optimally, the normal pH is often below 2 (that's very acid!). This is why drinking apple cider vinegar (which is acidic) actually improves gastrointestinal health. The oral cavity is much more alkaline compared to the stomach.
When people talk about making the body more alkaline they are failing to acknowledge that pH range varies tremendously depending on the location and function of a given system.
Blood pH
The pH balance of your blood stays within a very narrow range. If it changed too much you would go into a coma and die. For this reason it is ridiculous to think that any change in your diet will significantly affect your blood pH. If this was the case, we would never have survived as a species (that first pizza would've killed us off for sure).
Btw, checking your urinary and oral pH has nothing to do with blood pH. These numbers can change per meal making the conclusions people draw from them sometimes silly.
Buffer Systems
There are a handful of buffer systems that constantly adjust the climate of the body. The kidneys, for example, have two very crucial roles in maintaining the pH balance: to reabsorb and regenerate bicarbonate from urine, and to excrete hydrogen ions and fixed acids (anions of acids) into urine.
Your body adjusts its pH so that you don't have to.
How Food Can Actually Affect pH
If you eat foods that damage your body, and subsequently damage your buffer systems, then you're in trouble. For example, eating a diet high in carbohydrates (especially processed) is associated with diabetes and related kidney dysfunction. If the kidneys are not functioning properly then the acid balance function will be compromised resulting in acidosis (bad). But this is not because the carbohydrate foods are directly changing your pH!
Most food charts will show that fruit is very alkaline but, despite being alkaline, fruit is actually not good for a diabetic because it's high in sugar. Also important to note that proponents of Alkaline Diets encourage the consumption of vegetables which are truly great for health (just not for the reasons they're promoting).
Drinking Alkaline Water
Many of the claims are bogus and founded on false notions. With that said, these people are often experiencing improvements in their health. This could be for many reasons. If they joined a belief system then it could be psychogenic. Positive beliefs are powerful. In practice I come across many bizarre and unfounded ideas but if it helps the patient emotionally, and is not harmful, then I leave it alone. Joining MLMs (multilevel marketed) can be very motivating. A person might start taking better care of themselves, exercise more, eat better, and of course drink more water all of which will significantly improve health.
It also is possible that introducing large amounts of alkaline water into the stomach (which is functionally acidic) creates a compensatory response of the stomach to produce more acid thus improving its function. Digestion would improve short term but because the stomach is stressed it will be followed by a worsening of digestive function over time.
Claim: Cancer Grows in Acid
This is major oversimplification. Cancer is an opportunist and takes root in a compromised system. There are many aspects of that system to consider with each person being unique. Anyone pointing to the one and only factor is likely selling something. Some quote a scientist named Dr. Otto Warburg regarding his theory on fermentation and oncology however, people fail to understand the entirety of his research. His model of sugar dysmetabolism was based on mitochondrial dysfunction and changes in the extracellular matrix.
What to Eat?
The pH of many foods completely changes after digestion as the components hit the blood stream which makes food pH charts less useful. I see great foods above and below the neutral line. I suggest eating a whole foods diet low in processed foods and to see a doctor trained in clinical nutrition if needed for your specific requirements.