Symptoms of excess acidity
Why do opinions on the subject vary so widely? This is possibly because there are no clear symptoms that can be attributed to excess acidity alone. Signs of the condition can include anything from headaches to impure skin, digestive problems and dizziness, but they can also mean something completely different.
What does over-acidic mean?
Whether something is acidic or alkaline is shown by its pH value. A value below 7 is acidic, anything above that is alkaline. Human blood has a pH value of 7.4. Just a slight fluctuation is already life-threatening. This is why the body is able to regulate its pH value and buffer acids and alkalines.
How the body buffers acids
The most important buffer is the carbonic acid-bicarbonate buffer. This neutralises the acids that are ingested with food. The acids are exhaled in the form of carbon dioxide. About 2/3 of acids leave the body in this way. Not only are the lungs, kidneys and liver involved in long-term acid regulation, but a small amount is also released via our sweat glands and intestines.
Measurement with pH test strips
Evidence of acids being broken down is seen in the urine. In contrast to blood, the pH value of urine fluctuates between 5 and 8. Values within this range are considered harmless. You can use test strips to easily measure the pH value of your urine at home. However, this doesn’t tell you if you have excess acidity in your blood. The test result only tells you how much acid is excreted in the urine.
What excess acidity leads to
A study by the University Hospital of Lausanne showed that in people who eat a lot of acid-forming foods, the body is quick to compensate by tapping into the alkaline salts contained in our bones. In doing so, the body regulates excess acid but also loses calcium that is important for our bones. This means that even if urine values are within the normal range, following a strongly acid-forming diet over a longer period of time has an unfavourable effect on bone stability. Nonetheless: there are several studies on the subject whose summaries claim that this connection is not certain.
But not only that: a constant buffering of too many acids in the diet can promote the formation of urinary and kidney stones. Also popular in sources of advice on the subject is a theory known as connective tissue acidosis. It is said that excess acid in the diet over a long period of time leads to the formation of connective tissue waste, which is responsible for conditions like cellulite, for example. Even if it sounds plausible, this theory has never been proven.
Situations in which the body tends to become over-acidic
To detect excess acidity, laboratory diagnostics are needed as the pH value of a 24-hour urine test doesn't provide sufficient evidence.
Highly intensive physical activity leads to an increase in lactic acid concentration
Excessive alcohol consumption
The kidneys' ability to buffer acids decreases with age
Deacidify the body
Nevertheless, many sick patients who have to struggle with increased acid formation have found that deacidifying the body has a positive effect on their energy levels, digestion and well-being. An example: when competitive athletes practise intensive sport, the lactic acid concentration in their blood serum is briefly heightened. An alkaline-rich diet is therefore said to buffer the acids in the athletes’ bodies more effectively and therefore prevent exhaustion, and aid post-sport recovery.
When is a food acid?
The term «acidic» is often misunderstood when referring to food. Sour-tasting foods don't necessarily have an acid-forming effect during digestion. Protein building blocks that contain sulphur, such as those found in meat, form acids in the body. Fruit and vegetables, on the other hand, are generally alkaline due to the many minerals they contain.
The important thing is the way in which the food is metabolised – i.e. acid-forming or alkaline-forming – and not how it is in its original form. Indications of the acid content of individual foods vary greatly. What is the reason for this? Some sources give the pH value of the food, others how the value appears in metabolised form. In addition, the pH value changes depending on how the food is grown, prepared and digested.
The Swiss Nutrition Association classifies foods according to the system drawn up by Remer and Manz. In this system, the average acid load of different foods on the kidneys is given in PRAL (potential renal acid load). The higher the value, the more acid-forming the food. If the value is negative, the food is metabolised into alkaline. As a rule, the recommendation is to eat up to 80% alkaline-forming foods and only 20% acid-forming foods.