“Alkalising” diets are gaining popularity, and while the diet itself may be good and healthy, the thinking behind it is anything but. It is based on a complete misunderstanding of human anatomy and body chemistry. Let me explain.
Acid-alkaline chemistry is crucial in physiology, both at the cell level and the level of the complete body. There are two reasons for this: Many of the major chemical components of the body can themselves act as acids and/or alkalines. This means that proteins contain both acidic and alkaline groups and their functions are highly dependent on pH. Virtually every important metabolic process involves the uptake or release of hydrogen ions, so that being alive tends to change the surrounding pH – usually reducing it – and this will sooner or later kill the body in the absence of buffering agents.
Respiration, which is the most important physiological activity of a cell, is an acid-producing process. Carbohydrates are broken down into carbon dioxides and thus into carbonic acid, H2CO3.
The weak organic acids in the foods are in part in the form of sodium or potassium salts. So, when the body balances its pH level, some of the carbon dioxide (CO2) produced by metabolizing these food acids, it converts the acids into bicarbonate (M+ HCO3-). Do I need to tell you whether bicarbonate is acid or alkaline?
The acid-alkaline balance of the body is regulated by two general mechanisms, selective excretion of acids or alkalines and by the buffering action of weak acid-alkaline systems in body fluids. Over a 24h period, an adult human will eliminate carbonic acid which breaks down into carbon dioxide, which exits from the lungs. Kidneys also excrete lesser amounts of acid.
The major buffering system of the body is the carbonate system, and it exists mainly in the form of HCO3- at the normal physiological pH. Secondary buffering action is done by phosphate, proteins and other weak organic acids and hemoglobin in the blood cells.
No foods can change the pH of your body. Your stomach is so acidic – it evolved to be that way – that no food can change its acidity. All food that leaves your stomach is adicic. After leaving your stomach food enters your intestines, where pancreatic secretions neutralise the stomach acids. So it does not matter what you eat, the food in your stomach is acidic and the food in your intestines is alkaline. I know that “alkalising” cancer quacks claim that cancer cells cannot live in an alkaline environment, and that actually is true. What they leave out is that neither can any other cell of your body. So were you actually able to “alkalise” your body, you’d be very dead.
It’s actually a very good thing that you cannot “alkalise” your blood more than temporarily, as deviations from the normal blood pH of 7.4 by more than about 0.1 either way can be very serious. Some people who peddle “alkalising” claim that range of “healthy body pH is 6.0-7.5.” The term for anyone with a blood pH of 6.0 or lower is ‘dead’. Anyone with a blood pH of 7.0 is in deep trouble, and very close to death.
The easiest way of actually “alkalising” your blood is by hyperventilating. Give it a go, till your lips tingle and hands cramp – and then tell me how great you felt. If you still want to “alkalise” your blood, you can advance to depressurisation and dehydration. Be warned, though, alkalosis is a pretty painful way to die.
What you really can “alkalise” is your urine, and all “alkalising” woo peddlers capitalise on this fact. They huckster urine tests to determine whether your body is too “acidic” and then sell you books or products that won’t actually do anything at all about your body pH, only about your urine pH. There just is no evidence whatsoever that intentionally alkalising your urine prevents or treats disease.
This is why following an “alkalising” diet or buying “alkalising” supplements to cure or prevent cancer is a complete waste of time and money.