Abstract
In view of the current controversy whether external electrical currents are beneficial or detrimental to biological systems, a hypothesis is proposed attempting to reconcile the opposite viewpoints. Using the concept of minimum entropy production for systems far from thermodynamic equilibrium, it can be shown that a healthy (normal) biological system residing in its homeostatic (i.e., stable-steady) state is not affected by currents of physiologically acceptable magnitudes. If the system resides in stressed (unstable-steady) state, small perturbations may produce large changes in the state of the system. The changes caused by external electrical currents might be beneficial as well as detrimental, according to the proposed hypothesis. However, at the present state of knowledge, beneficial effects are supported by a solid body of experiments at the laboratory and clinical levels, whereas detrimental effects are hitherto suggested only by epidemiological studies.