REVIEW The Multiple Factors of Multiple Sclerosis: a Darwinian Perspective

Purpose: Multiple sclerosis (MS), an autoimmune disease of the central nervous system, is often referred to as a multifactorial disease, but there is little consensus as to what factors are involved, besides genetic susceptibility and childhood infectious agents. The purpose of this paper is to identify plausible, environmental factors that contribute to the aetiology of MS. Design: Review of the published literature. Materials and Methods: The probable environmental factors that promote MS onset and progression have been deduced from principles of evolutionary biology in conjunction with the currently accepted disease process. All environmental factors that either promote the activation of self-reactive immune cells or decrease immune regulation are considered to be potential causal factors. Those potential factors for which there are diverse inductive data that link them to MS onset and progression are deemed to be plausible, causal factors. Results: This analysis identified seven likely causal factors, all of which have been introduced into the human environment in the past 10,000 years by the agricultural, industrial and technological revolutions. Factors that promote the activation of autoreactive immune cells