Analysis of macro- and microelements in hairs

The concentration of trace elements may be determined both in body fluids and tissues. Concentration of trace elements in the blood often does not provide a complete picture of the content of these elements in the organism. This is caused by the fact, that the composition of plasma in large measure depends on homeostatic mechanisms and the final concentration of components is a result of balancing of their concentrations by various homeostatic mechanisms. The concentration of elements in the blood depends to a great extent on presently used diet. The currently used methods of evaluating the concentration of trace elements show high sensitiveness. These are: absorption atomic spectrometry (ASA), inductive coupled plasma spectrometry (ICAP), or neurone activation (NAA). These methods have permitted the detection of over 30 trace elements in hairs. Many pathological conditions are closely connected with changes of concentrations of trace elements in tissues. It has been proved, that the best method of determining the quantity of trace elements in human body is evaluating their concentration in hairs and nails. This is an alternative method to blood and urine analysis. Hairs and nails are outside the surface of the skin. They are excluded from metabolic processes. Nails are not as useful as hairs due to difficulties with complete removal of exogenous contamination. Hairs are neutral, permanent tissue, which does not undergo any biological changes. External keratin cuticle of hair effectively prevents both loss of internal components and penetration of exogenous contamination inside.

It maintains constant chemical composition in hairs. As opposed to nails, hairs can be cleaned of exogenous contamination very easily, which allows for best repeatability of analytic results. Samples of hair may be obtained in a non-invasive way. They may be stored and sent without any change in their chemical composition. The analysis of toxic trace elements in hairs is particularly valuable. The analysis of the concentration of trace elements in hairs is the best method of evaluating the mineral status of the body.

The hair tissue is built up of proteins containing a lot of cysteine. This aminoacid, due to the presence of the thiol group (SH), can chelate elements from transitory groups. Because of this, the concentration of trace elements in hairs is about fifty times higher than their concentration in blood and urine. Many scientific centres all over the world are involved in the study of the correlation between the concentration of trace elements in hairs and their quantity in the body, both in the state of physiological equilibrium and in pathological disorders.

Various mineral substances take active part in metabolic processes. They play an essential role as components of biochemical structures and also due to their physico-chemical properties. Metabolism of inorganic compounds, and in particular cations of metals (macro and microelements) is connected with enzymatic reactions in the body. The metabolism of macro and microelements is regulated by organic components. It plays a decisive part in all metabolic processes. It is dependent on the efficiency of hormonal and nervous systems activity.

The analysis of macro and microelements in hairs provides an exact description of the metabolic condition of the body. The mineral composition of the body is determined by external factors to a large extent. Depending on the type of food, physical activity and degree of pollution of the environment, various processes of mineralisation (deposition of mineral substances), demineralisation (elimination of mineral components) or transmineralisation (transfer of mineral components within the body) take place. Elements released in the course of metabolism can be used again for new metabolic processes.

Physiological processes in a living organism depend not only on the composition and concentration of particular elements, but also on their proportion. For various areas of the body various states of ion equilibrium exist, maintained on a constant level. Basing on the proportion between selected elements, metabolic activity and physiological processes can be evaluated. Among trace elements synergistic and antagonistic relationships exist, which directly affect the body metabolism. Maintaining of proper balance between individual elements is in many cases more important than their appropriate concentration.