In connection with the different views of scientists on the nature and mechanisms of aging, many different theories of aging have appeared:
1. The hysteresis theory – explains the aging process by changes in the colloidal state of cellular substances. The enlargement of colloidal particles leads to disruption of enzymatic processes, which in turn reduces the metabolic processes of the body.
2. The theory of “synthesis errors” means a violation in the synthesis of nucleic acids of RNA and DNA, which carry hereditary information on the chemical structure of proteins of living tissue, being their “spatial matrices”. Aging, the authors of this theory associate with synthesis errors in the mechanism of protein reproduction.
3. The stereochemical theory proceeds from the notions of the spatial redistribution of atoms and radicals in the molecules of living matter in the process of self-renewal.
4. The theory of ontogenesis (the doctrine of the development of the individual). Damage and death of somatic cells is caused either by random causes or by the redistributed effect of genetic factors. Throughout life, not all cells die, but only part of them, which weakens the viability of the body,
5. The biological concept of stress. Aging is the result of all the stresses that the body undergoes throughout life. It corresponds to the phase of “exhaustion” of the general adaptation syndrome (OSA). But the difference between aging and OSA is that the latter is more or less reversible after rest. At the same time, any stress, especially if it leads to disturbances (distress, frustration, that is, to mental collapse, exhaustion, illness), leaves behind the body irreversible Chemical scars. ”Their accumulation causes signs of tissue aging.
6. Theory of autointoxication, ie self-poisoning of the body.
7. The theory of molecular genetic mechanisms of aging explains aging by changes in the molecular structure and function of the somatogenetic apparatus of the cell. According to her, aging is an active period of ontogenesis, which consists not only of the processes of gene regression, their involution, but is also associated with the opposite processes – gene degradation, i.e. there is a “programmed death” of non-dividing cells, as well as the propagation of some mutant (dividing cells of connective tissue).