The Multiple Factors of Multiple Sclerosis: A Darwinian Perspective
Journal of Nutritional & Environmental Medicine (December 2004) 14(4), 307–317
- 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: (1) infectious agents that have crossed over from domesticated animals; (2) new food types introduced by agriculture (dairy, grains, legumes); (3) reduced fibre consumption in concert with an excessive intake of sugar, starch and antibiotics. Factors that decrease immune regulation: (4) deficiency in vitamin D; (5) deficiency in omega 3 essential fatty acid (EFA) in concert with an excess of omega 6 EFA; (6) deficiency in antioxidants in concert with increased oxidative factors; (7) paucity of chronic infections due to the establishment of hygienic conditions.
Conclusions: The greatly increased supply of cross-reactive antigens from agriculture, in combination with decreased immune regulation from industrialization, has resulted in a huge increase in the incidence and prevalence of MS over the past 200 years. The identification of these probable causal factors of MS leads to common sense, nutritional strategies for reducing the risk of MS and for helping those with MS control disease progression.