Is there an optimal pH value?
In saliva, the pH value should be slightly alkaline, i.e. about 7-8. At a pH of 6.7, demineralization of the teeth begins and at 5.5 even the enamel is attacked. When sugar is absorbed, the pH value is lowered by the acid produced by the bacteria.
If you have a rather alkaline saliva as a starting value, the pH does not move so quickly into the critical acidic range and can regenerate more quickly into the alkaline range after eating. The blood has an optimal pH value between 7.35 – 7.45. It is important that the blood pH value is kept constant within narrow limits.
Many enzymes can only work well enough to maintain metabolism within a certain pH value. In order to maintain the pH value between 7.35 – 7.45, there are various buffer systems in the blood that can balance out too many acids or bases (phosphate buffer, bicarbonate buffer, hemoglobin buffer). If these buffers fail, the changed pH value is also reflected in the saliva.
How can the pH value in saliva be measured?
If you want to measure the pH-value in saliva, for example to conclude that the body is over-acidified, you have to follow a few rules. The pH value of the saliva depends heavily on how actively the salivary glands secrete. For this reason, stimulating the glands (e.g. by eating food shortly before the measurement) would falsify the measurement result.
The more active the glands are, the more alkaline the saliva becomes. This is because a faster flow of saliva means that there is less time to reabsorb sodium ions from the initially plasma-isotonic saliva in the excretory ducts of the glands. It is therefore important not to eat or drink for about two hours before the measurement.
A fasting pH value of the saliva can then be easily compared with the pH value of the small intestine, for example. To measure the pH value yourself, you can buy pH test strips. Then you must moisten the test strip with a little saliva, e.g. from the tongue.
Then you rinse your mouth with lemon juice and measure the pH with a new test strip. For better test results, repeat the measurement a few times in two minutes (without rinsing the lemon again). How fast the pH value rises (i.e. becomes more alkaline) is an indication of how good the buffer function of the blood is.
If the blood buffers well, it can easily compensate for deviating pH values (such as those caused by citric acid). The faster the pH value rises again after rinsing with lemon juice (i.e. becomes more basic), the better. The buffer capacity is poor if the pH value is still below 7.0 after 10 minutes (a pH of 8.0 should be aimed for).
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