In previous blogs I have looked at pica and some of the pica sub-variants including pagophagia (the eating of ice) and coprophagia (the eating of faeces). Pica is defined as the persistent eating of non-nutritive substances for a period of at least one month, without an association with an aversion to food. Today’s blog takes a look at geophagia (the eating of earth, soil and/or clay). In a literature review published in the Journal of the Royal Society of Medicine by Dr Alexander Woywodt and Dr. Akos Kiss that geophagia has been regarded as a psychiatric disease, a culturally sanctioned practice and/or a sequel to poverty and famine. Geophagia is also a culturally sanctioned practice in some parts of the world. Woywodt and Kiss also stated that:
“[Geophagia] is not uncommon in southern parts of the United States5 as well as urban Africa. Fine red clay is often preferred. In particular, geophagia is observed during pregnancy or as a feature of iron-deficiency anaemia. Where poverty and famine are implicated, earth may serve as an appetite suppressant and filler; similarly, geophagia has been observed in anorexia nervosa. However, geophagia is often observed in the absence of hunger, and environmental and cultural contexts of the habit have been emphasized. Finally, geophagia is encountered in people with learning disability, particularly in the context of long-term institutionalization”.
The relationship between anaemia and pica (including geophagia) has been well documented. However, Woywodt and Kiss assert that it is still unclear whether anaemia prompts geophagia to compensate for iron deficiency or whether geophagia is the cause of anaemia. Prevalence rates of pica have range anywhere between 0.02% and 74% depending on the study and population studied although there are few reliable prevalence estimates of geophagia. One study of pregnant Tanzanian women found a prevalence rate of 26.5% (but this is – of course – a totally unrepresentative sample).
A recent review on pica led by Dr Sera Young (University of California, USA) noted that geophagia is the most common type of pica described in the psychological and medical literature although it did also report that geophagics frequently eat other non-food stuffs (particularly if the desired soil is unavailable or socially unacceptable). For many people, pica is not dangerous but for geophagia there may be complications including parasitic infections (from eating soil). Although eating soil and clay may be regarded as unappetizing (and perhaps bizarre) by most people, some authors have argued that eating soil can be nutritionally beneficial (which if that was the case, it wouldn’t technically be a form of pica).
While not being considered a social norm in Western society, eating soil or clay is said to be quite common among primitive or economically depressed peoples a way of augmenting a scanty and/or mineral-deficient diet. Having said that, the geophagia is most often confined to people suffering from chronic mental illness. Clay (as opposed to soil) consumption has been reported in India, Haiti, various parts of Africa (Cameroon, Gabon, Guinea), and even rural areas of the USA. Like soil consumption, clay consumption has also been associated with pregnant women and some women claim they eat it to eliminate nausea. The Wikipedia entry on geophagia noted:
“In Haiti, the poorest economy in the Western Hemisphere, geophagy is widespread. The clay mud is worked into what looks like pancakes or cookies, called ‘bon bons de terres’…The cookies have little or no nutritional value and are associated with various health problems”.
A study led by Dr. L.T. Glickman and colleagues, and published in a 1999 issue of the International Journal of Epidemiology, provided some data on geophagia by carrying out a study examining intestinal parasitism among children from three rural villages in Guinea (Africa). More specifically they examined the faecal stools of 266 randomly selected children (aged 1-18 years). The researchers found that 53% of children were infected by at least one type of soil-transmitted parasite. They also surveyed parents and reported that geophagia was reported by parents to occur in 57% of children aged 1-5 years, 53% of children aged 6-10 years, and 43%, of children aged 11-18 years. It was concluded that geophagia is an important risk factor for orally acquired parasitic infections in African children.
A small study carried out by Turkish researchers and published in a 1978 issue of Acta Haematologica carried out oral iron and zinc tolerance tests on 12 patients from Turkey and Iran aged between 8 and 21 years with iron deficiency anemia and geophagia. The research team reported decreased iron and zinc absorption in patients compared to control patients. They concluded that iron and zinc malabsorption may be an additional feature of the syndrome characterized by geophagia among those from Turkey and Iran. Finally, in their literature review on geophagia, Dr Woywodt and Dr Kiss concluded that:
“The causation is certainly multifactorial; and clearly the practice of earth-eating has existed since the first medical texts were written. The descriptions do not allow simple categorization as a psychiatric disease. Finally, geophagia is not confined to a particular cultural environment and is observed in the absence of hunger”
Dr Mark Griffiths, Professor of Gambling Studies, International Gaming Research Unit, Nottingham Trent University, Nottingham, UK
Arcasoy, A., Cavdar, A.O. & Babacan, E. (1978). Decreased iron and zinc absorption in Turkish children with iron deficiency and geophagia. Acta Haematologica, 60, 76-84.
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Glickman, L.T., Camara, A.O., Glickman, N.W. & McCabe, G.P. (1999). Nematode intestinal parasites of children in rural Guinea, Africa: Prevalence and relationship to geophagia. International Journal of Epidemiology, 28, 169-174.
Kettaneh, A., Eclache, V., Fain, O., Sontag, C., Uzan, M. Carbillon, Stirnemann, J. & Thomas, M. (2005). Pica and food craving in patients with iron-deficiency anemia: A case-control study in France. American Journal of Medicine, 118, 185-188
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López, L.B., Ortega Soler, C.R. & de Portela, M.L. (2004). Pica during pregnancy: A frequently underestimated problem. Archivos latinoamericanos de nutricion, 54, 17-24.
Nyaruhucha, C.N. (2009). Food cravings, aversions and pica among pregnant women in Dar es Salaam, Tanzania. Tanzania Journal of Health Research, 11(1), 29–34.
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Woywodt, A. & Kiss, A. (2002). Geophagia: the history of earth-eating. Journal of the Royal Society of Medicine, 95:143-146.
Young, S.L., Wilson, M.J., Miller, D., & Hillier, S. (2008). Toward a comprehensive approach to the collection and analysis of pica substances, with emphasis on geophagic materials. PLoS One, 3(9), e3147.
Wikipedia (2012). Geophagy. Located at: http://en.wikipedia.org/wiki/Geophagy