Allostatic Load

Allostatic load is a concept introduced by Bruce McEwen and Eliot Stellar of Yale University in 1993 as a critical expansion of the theory of allostasis. Allostasis itself is a revision of the classical theory of homeostasis, which describes the way internal physiological systems work together to reestablish initial conditions (prior “set points”) when the body’s functioning is perturbed. Under allostasis, however, an organism makes adaptive shifts across a broad range of physiological systems in order to match internal functioning to environmental demand.

These adaptations are mediated by the brain and have cascading effects in peripheral systems, [Page 104]producing organism-wide changes to find a new homeostatic balance that better fits the circumstances (i.e., new “set points”). When the organism experiences chronic, extreme, or repeated stress, the ...