16 February 2007

Body pH: A delicate balance

Body pH and the delicate balance between acid and alkalinity are very complex topics, which are often confused with other conditions. DietDoc takes a look at some basic concepts.

Body pH and the delicate balance between acid and alkalinity are very complex topics, which are often confused with other conditions. DietDoc takes a look at some basic concepts and the role of the diet.

Acid-base balance
The acid-base or acid-alkaline balance of the human body refers to the pH or number of hydrogen ions in the body as a whole. If you have an oversupply of hydrogen ions in your body, your pH will be acid or low (e.g. pH 4), and your body will be in a state of acidosis.

If your body has a high pH (e.g. pH 8), it is alkaline and in a state of alkalosis.

The human body is a marvellous system that maintains its pH in a narrow normal range between pH 7,35 and 7,45, despite the large load of acid introduced by diets and produced by tissue metabolism. Most of the metabolic processes in the human body can only take place if the pH of the body is in the normal range.

Acid production in the gastrointestinal tract
The basic acid-base balance of the human body should never be confused with acid that is produced by the stomach during digestion. The human stomach normally has an acid pH and produces hydrochloric acid, which aids digestion.

Many factors can trigger overproduction of stomach acid, for example:

  • Stress
  • Alcohol
  • Smoking
  • Infection with a bacterium called Helicobacter pylori
  • Excessive intake of irritants such as spices and caffeine (coffee, tea, cola drinks and certain caffeine-containing energy drinks)

The overproduction of stomach acid can lead to:

  • Heartburn
  • Gastritis
  • Gastro-oesophageal reflux
  • Stomach ulcers

Treatment for overproduction of stomach acid includes:

  • Antacids
  • Proton-pump inhibitors (medications that reduce the amount of acid the stomach produces)
  • Antibiotics to eradicate Helicobacter pylori infections
  • Avoidance of alcohol, spicy food and condiments, cigarette smoking, rich, fatty foods and caffeine
  • Avoidance of individual foods that may cause discomfort to specific patients - this is often an individual reaction so that some patients need to cut out white bread, while others need to avoid brown bread
  • Reduction of stress by exercise, relaxing exercises, psychotherapy, anti-stress medication, hypnotism, yoga or any other method that relieves stress and anxiety

Keep in mind that the amount of stomach acid you produce does not influence the acid-base balance of your body. An individual with a stomach ulcer or someone who is producing too much stomach acid can have an alkaline body pH and vice versa.

Disorders of the acid-base balance
Certain conditions can disturb the delicate balance of the body’s pH.

The condition called metabolic acidosis can be caused by the following:

  • Diabetic ketoacidosis (overproduction of acid compounds called ketones caused by breakdown of fat for fuel in the absence of sufficient blood glucose supplies, which are in turn due to the lack of insulin or the inability of insulin to work properly)
  • Lactic acidosis - build-up of lactic acid in the body due to excessive exercise or certain diseases
  • Uraemia - build-up of ureum in the body due to kidney failure

The condition called metabolic alkalosis can be caused by the following:

  • Excessive intake or accumulation of bicarbonates in the body
  • Excessive loss of acid (e.g. nasogastric suction)
  • Loss of extracellular fluid due to tumours or overuse of diuretics
  • Potassium deficiency

Each one of the above-mentioned conditions has to be treated by reversing the functional problem. For example, a diabetic has to take insulin to prevent ketoacidosis. None of these conditions are caused by eating acid or alkaline food.

The pH of food
It is often difficult to understand that food, which have an acid taste, such as pineapple, strawberries, or lemons, do not make the pH of the body acidic or cause acidosis. This is due to the fact that the effect food have on the pH of the body is determined by the acid or alkaline content of the ash they produce when the body has finished metabolising them.

Most fruits, vegetables, milk and some nuts produce an alkaline ash and will make the body pH more alkaline.

Meat, fish, poultry, cheese, eggs, cereals and some nuts produce an acid ash and will make the body pH more acid.

Acid-ash-producing food:
Bread (especially wholewheat), cereals, cheese, maize, crackers, cranberries, eggs, lentils, pasta, meat, fish, poultry, pastry, peanuts, plums, prunes, rice, walnuts.

Alkaline-ash-producing food:
Milk, fruits, vegetables, almonds, dried apricots, Lima and navy beans, chard, dates, figs, molasses, olives, dried peas, parsnips, raisins, watercress, foods prepared with baking powder or bicarbonate of soda

Neutral food:
Butter, hard, boiled sweets and candy, coffee, Maizena, fats, oils, lard, honey, sugar, tapioca, tea. – (Dr I.V. van Heerden, DietDoc)

Any questions? Ask DietDoc


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