El concepto de alostasis: un paso más allá del estrés y la homeostasis

Abstract

In an attempt to understand the process of development of disease and taking a holistic view of medicine, we can no longer understand stress only as a defense mechanism of the organism against aggression. Many everyday situations force a number of physiological responses which together result in a more complex answer; here the concept of “allostasis”. As a response to psychological or physical stress, internal or external, allostatic systems activate the autonomic nervous system, the hypothalamic-pituitary-adrenal axis, the cardiovascular system, metabolism, and the immune system. Facing a new situation generates a cognitive evaluation, which is conditioned by each individual’s genetics, experiences during development, and behavior acquired throughout life, all resulting in a neuro-immune-endocrine response, which is initially physiological and yields to adaptation. When allostasis is ineffective or inappropriate, or the stressor agent extends over time, adaptation is not achieved, producing what is known as “allostatic load”. In the long term, this may result in both organic and psychological disease. Understanding the concept of allostasis and allostatic load, allow us to have a more inclusive and complex insight on stress and homeostasis, a classical subject often times oversimplified. The search for answers for why we get sick forces us to think about the relationship between genetics, environment and interindividual vulnerabilities in the process of becoming ill