Disease family trees: the possible roles of iodine in goitre, cretinism, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's and Parkinson's diseases and cancers of the thyroid, nervous system and skin.
Geographical distribution patterns of incidence and mortality for a wide variety of diseases display strong positive and negative correlations when analyzed statistically. It is argued that these relationships do not occur by chance, but reflect the causal role of surpluses and/or deficiencies of various bulk and trace elements. This concept is explored for one such "disease family tree", that of iodine. Deficiencies of this essential trace element appear to be associated with many diseases, or birth defects, including goitre, cretinism, multiple sclerosis, amyotrophic lateral sclerosis and cancer of the thyroid and nervous system. Although the evidence is weaker, iodine deficiency may also be implicated in Alzheimer's and Parkinson's diseases. In contrast, too much iodine may be linked to elevated mortality from cancer of the skin and melanoma. Rat studies indicate that iodine deficiencies can cause reduced brain weight, limited myelin formation, retarded neuronal maturation, a lowering of the production of various enzymes and slowing of the rates of protein and R.N.A. synthesis. Similar processes appear to occur in many of the diseases identified above.
Foster
H D
HD
Department of Geography, University of Victoria, British Columbia, Canada.
D000544:Alzheimer Disease / Q000209:etiology; D000690:Amyotrophic Lateral Sclerosis / Q000209:etiology; D003409:Congenital Hypothyroidism / Q000209:etiology; D006042:Goiter / Q000209:etiology; D006801:Humans; D007455:Iodine / Q000172:deficiency / Q000502:physiology*; D009103:Multiple Sclerosis / Q000209:etiology; D009423:Nervous System Neoplasms / Q000209:etiology; D010300:Parkinson Disease / Q000209:etiology; D012878:Skin Neoplasms / Q000209:etiology; D013964:Thyroid Neoplasms / Q000209:etiology
D007455:Iodine