The metabolic activity of cells produce variable amounts of inorganic acids, such as carbonic acid, and organic acids such as lactic acid, uric acid, free fatty acids or not esterified (NEFA, non esterified fatty acids),etc. Each acid has a precise origin, follows a well-defined metabolic fate and performs a specific function. The degree of acidity detectable in the microcirculation, which reflects the sum of the production of different acids derived from tissue metabolism, plays a crucial physiological role in the regulation of exchanges between blood and cells. Indeed, increased levels of acidity within certain limits reduces vascular tone (vasodilation) and promotes the transfer of oxygen from hemoglobin, resulting in improved perfusion of tissues and organs. However, an excessive increase of total acidity, changing the conformation of plasma proteins, facilitates the release from transferrin and ceruloplasmin of transition metals such as iron and copper. As a result, there is the activation of Fenton’s reaction and peroxyl radical generation by circulating hydroperoxides; these are the events that are the base of the oxidative stress and its dangerous consequences (e.g. atherosclerosis). Severe and/or prolonged acidosis, exceeded the physiological mechanisms of compensation, may extend from the plasma to the tissues, aided the concomitant alterations of the extracellular matrix (increased proteolysis and reduced protidosynthesis), resulting in amplification of the damage from oxidizing chemical species ( free radicals). Ultimately, an abnormal increase in the level of acidity in the microcirculation (microacidosis) is often "the antechamber" of oxidative stress.

Unfortunately, at present, the only test that can measure the acid-base balance in the blood is the pH test which measures the concentration of hydronium ions (H₃O⁺) in serum / plasma. Its values are between 7.34 and 7.38, but information is not enough about the acidity of the blood and when they are altered do not provide any useful indication for possible correction by alkalinization.

The MAc Test (biological titratable acidity), however, permit to determine this important parameter according to the principle of titratable acidity (in technical terms: the addition of equivalent basis according to the measured concentration of acid).

Less than 440 p.p.m. are values considered optimal. Values above indicate a microacidosis conditions. In this case, will the physician should determine, through the inclusion of test results in the clinical picture of each specific patient, what strategy should be put in place in order to bring back to normal any outliers.

Maintaining the acidity within normal limits is the simplest of safeguards that can prevent tissue damage from free radicals and thus oxidative stress and all its undesirable consequences.

The nutrients of our alimentation can be acidifying or alkalizing and they can affect the acidity. For this reason to measure the acidity is the correct way, from a scientific perspective, to choose the food best suited to your body in a particular metabolic context and monitor the temporal effects on health status.