Lambert V, Boukhari R, Misslin-Tritsch C, Carles G
Service de gynécologie obstétrique, centre hospitalier de l'Ouest Guyanais, Saint-Laurent-du-Maroni, Guyane française.
Rev Med Interne. 2013 Feb;34(2):94-8. doi: 10.1016/j.revmed.2012.07.012. Epub 2012 Sep 14.
Geophagia is an ancient practice subject to many prejudices. Recent animal experiments have shed light on its causes and consequences. Geophagia, a form of pica, may be induced by various factors. Clay, the material preferentially ingested by geophagic subjects, interacts with the food bolus and the digestive mucosa. Its capacity to form colloids and to adsorb and exchange ions results in both beneficial and harmful effects. In a less civilized age, the ingestion of clay may have reinforced digestive barriers against alkaloids and toxins, conferring a selective advantage on individuals practicing geophagia. However, in the modern Western world, complex interactions of clay with metals and ions are likely to generate low-level poisoning and deficiencies, potentially damaging the health of geophagic individuals and their offspring.
食土癖是一种饱受诸多偏见的古老行为。近期的动物实验揭示了其成因及后果。食土癖作为异食癖的一种形式，可能由多种因素诱发。黏土是食土者优先摄取的物质，它与食团及消化黏膜相互作用。其形成胶体以及吸附和交换离子的能力会产生有益和有害两种影响。在文明程度较低的时代，摄入黏土可能增强了对生物碱和毒素的消化屏障，赋予了有食土癖行为的个体一种选择优势。然而，在现代西方世界，黏土与金属和离子的复杂相互作用很可能导致低水平中毒和营养缺乏，有可能损害食土者及其后代的健康。
