Antioxidant capacity (ImAnOx, TAS)

Antioxidant capacity, also called TAS (total antioxidant status), describes how much reactive oxygen species the blood can neutralise overall. It is measured in serum. In the ImAnOx method, a fixed amount of hydrogen peroxide is added to the sample; the antioxidants in the serum break down part of it, and the laboratory determines how much is left. The less peroxide remains, the greater the buffering capacity. Unlike the measurement of individual vitamins, the value captures the interplay of all defence substances in the blood at once. In the test catalogue it belongs to the „oxidative stress“ group in the acne profile.

What antioxidant capacity shows in the body

During energy production in the mitochondria, during inflammation and in the defence against germs, reactive oxygen species such as superoxide and hydrogen peroxide are constantly formed. In small amounts they act as signalling substances; in large amounts they attack fats in cell membranes, proteins and genetic material. The blood neutralises them with a whole network: uric acid contributes a large part of the plasma's capacity, alongside albumin, bilirubin, vitamins C and E, glutathione and plant compounds such as polyphenols. Enzymes such as glutathione peroxidase and catalase work mainly inside the cells. The TAS value therefore reflects the sum of the antioxidants dissolved in serum.

Low antioxidant capacity – what happens in the body?

When capacity is low, fewer neutralising substances face the radicals being formed. Oxidative stress occurs more easily: fats in the cell membranes are oxidised, proteins change their shape and function, and damage arises in genetic material, which shows, for example, as 8-OHdG in urine. Oxidised components in turn act as an inflammatory signal, so inflammation and oxidative stress can reinforce each other. In the skin, such an imbalance has been observed in studies in acne, among other things in connection with oxidised skin lipids. Low values occur with chronic inflammation, smoking, heavy physical strain without adequate recovery, a diet low in fruit and vegetables, and with low uric acid or low albumin.

High antioxidant capacity – what does it mean?

A high value means that the serum can break down a lot of peroxide. This may reflect a good supply of antioxidant nutrients, for example from a diet rich in vegetables and fruit or from vitamin preparations shortly before the blood sample. Because uric acid and bilirubin make up a large share of the measured value, it also rises when these substances are raised – for example with high uric acid or with a liver disorder. A high value is therefore not automatically a sign of particularly little oxidative stress. It is interpreted together with uric acid, inflammation markers and other markers of oxidative stress such as 8-OHdG or glutathione.

The interpretation is given in your report.