Association between geophagia and haematological parameters of iron deficiency anaemia amongst geophagic Qwa-Qwa women

Abstract

Pica is the habitual eating of non-food substances by humans and animals. It has different subgroups and these are defined by the ingested substance. Moreover, geophagia is a type of pica that refers to the consistent eating of mostly earth and earth-like substances such as clay and soil. It is observed in both sexes, all age groups and in different ethnic groups around the world. There are many reasons people give for the practice of geophagia, such as culture, hunger and health being the most prominent. Geophagic materials differ in texture, colour and taste. Soil colour classification according to the Munsell soil classification, which uses hues, values and chroma, sometimes differ with the soil colour being noticeable with the naked eye. However, geophagic clays from Qwa-Qwa are white and contain kaoline.

Geophagic materials are believed to augment mineral deficiency, especially magnesium, calcium and iron. Geophagia is practised mainly by females, especially during their child bearing years. Females are more prone to iron deficiency anaemia due to their monthly menstruation cycle. Iron deficiency is the most common cause of anaemia and is classified as hypochromic microcytic anaemia (HMA). This study focused on the health aspect of geophagia. The research question seeks to explore whether there is an association between geophagia and the haematological parameters of iron deficiency anaemia. Geophagia seems to be linked with the occurrence of anaemia, but not iron deficiency anaemia, although it is implied. It is not known if the practice of geophagia causes iron deficiency anaemia or if it is because of iron deficiency anaemia that people practise geophagia. A pilot study was done in 2007, and the results of that study prompted that this study be performed on a bigger scale.

The lack of information regarding the quantity, frequency and type of geophagic material consumed the impact of geophagia on haematological parameters and the iron status of the geophagists made it important that the primary existence of the iii

relationship be investigated. In addition, research to establish whether there is a relationship between geophagia and haematological parameters of iron deficiency anaemia, has not been undertaken in South Africa, especially on non-pregnant women. Geophagia seems to always be accompanied by the subject of iron deficiency anaemia and especially its prevalence in females. The bigger geophagia project was therefore an ideal opportunity to do a specific survey on geophagic women.

This was a cross-sectional study, consisting of 36 control women and 47 geophagic women, aged between 18-45 years. The participants completed a questionnaire to determine the geophagic practices, which included the colour of the clay, how frequent the clay was consumed, how much was consumed and for how long it has been consumed. Nutritional status was assessed using a food frequency questionnaire. Blood was drawn to assess the haematological and iron status of the participants.

The participants of the study were within the required age range, with no significant difference between the groups (p-value=0.7914). The most consumed colour of clay was white and white clay contains kaoline, which has the ability to absorb iron in the duodenum. The majority of the participants consumed 40 grams of clay on a daily basis, with most of the participants having done so for 5 years. Diet was ruled out as the cause of iron deficiency.

The haematological parameters indicated that the geophagic group (43%) were inclined to have hypochromic microcytic anaemia, while a small percentage of control groups (8%) had HMA; this was revealed by the red cell parameters and red cell indices. In addition, the odds ratio for the haematological results revealed that the probability of a geophagic person developing anaemia was two times greater than that of a non-geophagic person. Platelet results partially ruled out bleeding as a cause of anaemia. The median red cell distribution width indicated that the iv

geophagic group was inclined to have anisocytosis. The geophagic group was found to have iron deficiency (75%), whilst the control group had a small percentage with iron deficiency (22%), which was validated by the serum ferritin, serum iron and saturated transferrin (chemical analysis). The odds ratio revealed that the probability of a geophagic person being iron deficient is 3 times greater than that of a non-geophagic person. The strongest association is seen with iron study findings, because being iron deficient showed the highest odd ratio than the association with red cell morphology and even haemoglobin. Thus, participants were more iron deficient than suffering from iron deficiency anaemia.

Inflammatory and parasitic indicators proved that inflammation and infection was uncommon in both groups, and therefore did not compromise the credibility of the iron study results. Inflammatory indicators (white blood cells, erythrocyte sedimentation rate and C-reactive protein) ruled out inflammation, whilst eosinophil count showed no indication of parasitic infection for both geophagic and control groups.

To conclude, the study found that an association exists between geophagia and haematological parameters of iron deficiency anaemia amongst geophagic women in Qwa-Qwa, in that geophagic material contributes to iron deficiency anaemia.