Geophagia: why do humans consume soil?

Abstract

Summary Geophagia is an ancient practice which is still widely seen in many parts of the world, especially in traditional societies. Soils, selected for particular qualities, such as flavour and plasticity, from carefully chosen sites, are consumed for a variety of reasons, from religious to medicinal, as well as part of a regular diet. The practice has been criticised as unhygienic because it can expose consumers to toxic soil constituents, such as heavy metals or parasites. It has also been suggested that it causes iron deficiency anaemia. However, there is evidence that soil can be a valuable source of trade elements and nutrients. A number of investigations are currently been carried out to resolve such conflicting views and to provide data on which an objective judgement can be made regarding the clinical, medicinal and nutritional implications of the practice.