Human geophagia, calabash chalk and undongo: mineral element nutritional implications

Chemical analysis of calabash chalk and its effect on locomotor activities and behavior in Swiss albino mice

Continuous exposure of young women to calabash chalk, especially at child-bearing age, necessitated this study to analyze the chemical constituents of calabash chalk and to evaluate its effect on locomotor activities and behavior in Swiss albino mice. Dried cubes of calabash chalk were purchased and analyzed by atomic and flame atomic absorption spectrophotometer. Twenty-four Swiss-albino mice were taken and divided into four groups: control (1 ml distilled water) and three treated groups with the doses of 200 mg/kg, 400 mg/kg, and 600 mg/kg of calabash chalk suspension, respectively, by oral gavage. Hole Cross, Hole Board, and Open Field tests were performed to evaluate the locomotor activities, behavior, and anxiety along with measurement of body weight. The data were analyzed by SPSS-software. Chemical analysis of calabash chalk showed the presence of trace elements along with some heavy metals such as lead (19.26 ppm), Chromium (34.73 ppm), and arsenic (4.57 ppm). After 21 days of oral administration of calabash chalk, the study showed a significant decrease in body weight in the treated groups of mice (p < 0.01). Decreased locomotor activities were also observed in all three experiments. Significantly decreased locomotion and behaviors were also observed in the hole crossing, line crossing, head dipping, grooming, rearing, stretch attend, central square entry, central square duration, defecation, and urination, in a dose-dependent manner (p < 0.01). These effects also prove the anxiogenic behavior of calabash chalk in albino mice. Heavy metals are believed to be harmful to the brain and responsible for cognitive dysfunction and elevated anxiety. In this study, decreased body weight in mice may occur due to disorders in hunger and thirst centers of the brain by heavy metals. Therefore, heavy metals may be responsible for muscle weakness, decreased locomotor activities, and axiogenic effects of mice.

Current status of research and gaps in knowledge of geophagic practices in Africa

This article synthesises current knowledge and identifies research gaps on the still intriguing aspects of the subject of geophagy as practised in Africa. Despite the voluminous research literature that exists on the subject, geophagy in Africa is still a largely misunderstood phenomenon. Although the practice is not confined to any particular age group, race, gender, or geographical region, in Africa it is most commonly recorded among pregnant women and children. Till now, the precise aetiology of geophagy remains obscure; but the practice is thought to have both beneficial effects such as having a role as a nutrient supplement, as well as several demerits. An updated critical review of human geophagy in Africa - with a section on (other) animal geophagy -, highlights several aspects of the practice that need further research. A comprehensive bibliography is assembled, comprising some of the more pertinent and recently published papers (mostly post-dating the year 2005), as well as older seminal works, providing a baseline and robust framework for aiding the search process of Medical Geology researchers and those from allied fields wanting to explore the still poorly understood aspects of geophagy in Africa.

Geochemical and mineralogical composition of geophagic materials from Baringo town, Kenyan Rift Valley and their possible health effects on the consumers

Consumption of geophagic materials can be detrimental to human health. These materials, which are harvested from the natural environment, can contain high concentrations of potentially harmful elements and minerals. In this study, mineralogical and geochemical investigation of geophagic rock materials consumed by the local population in Baringo town, in Kenya, was conducted to assess its possible health effects. Twelve representative samples were purchased from an open market in Baringo town for this investigation. Optical and scanning electron microscope as well as X-ray diffractometer was used to determine the mineralogy as well as the morphology of the minerals present in the studied samples. The material is composed of about 10 to 20% coarse to very coarse (0.38-3.00 mm) and semi-rounded to angular crystals of quartz, feldspars, and amphiboles, together with lithic fragments occurring in a fine-grained matrix. X-ray fluorescence and inductively coupled plasma mass spectrometry were used to determine the major and trace elements composition, respectively. The analyses show that elements such as Si, Fe, Mn, Al, Hg, Cr, Cd, and Pb are particularly above their recommended daily allowances. This study assumes 100% bioavailability of elements in the geophagic materials, in the absence of a bioaccessibility test. Therefore, the consumption of some of the revealed elements, based on this assumption, can be detrimental due to possible short- and/or long-term health effects. From a mineralogical point of view, the presence of feldspar and quartz with Moh's hardness of 6 and 7, respectively, and their coarse and angular morphology may cause damage to the dental enamel and the gastrointestinal tract. From a geochemical point of view, the high concentrations of the revealed chemical elements can have various health effects including, but not limited to neurotoxic effects, which are critical in prenatal exposure, neurodegenerative diseases, and cancer amongst other serious diseases.

Geophagic clay around Uteh-Uzalla near Benin: mineral and trace elements compositions and possible health implications

Geophagic clay consumption, which is an age-long cultural practice by humans and animals in many parts of the world, and particularly in Nigeria, may have long time health effects on the consumers. This is particularly so because of the relatively high concentration of harmful minerals and toxic elements. This study sought to determine the mineralogical and trace element compositions of geophagic clay in Uteh-Uzalla area, which is underlain by the Benin Formation of Oligocene to Miocene age, in order to evaluate the potential health risk associated with the consumption of the clay. Sixteen clay samples were collected from mine face profiles of an open pit, analysed for mineral and trace element compositions, using x-ray diffraction technique and ultra-trace inductively coupled plasma mass spectrometry (ICP-MS) methods, respectively. The mean mineral concentration in % includes kaolinite, quartz and smectite (64.88, 19.98, and 9.54), respectively, among other minerals. And the mean concentrations in mg/kg for Cu (15.0), Pb (14.4), Zn (30.9), Co (8.9), Mn (39.4) and Th (10.5) among other elements were found in the clay. From the trace elements results when compared with health risk indices by Agency for Toxic Substances and Diseases Registry (ATSDR): Minimum Risk Level, recommended daily intake and estimated daily intake, it was found that the elements are far above the daily oral intake requirement. Also, considering the relatively low pH (acidic) values that were exhibited by the clays, harmful minerals and elements contained in the clay may be bioavailable in the internal system among those who are frequently involved in the consumption of the clay.

Cadmium and lead in geophagic clay consumed in Southern Nigeria: health risk from such traditional nutraceutical

Geophagy is a cultural behavior, based on the recurrent intentional eating of clay soil, that is raising increasing concern as it implies multidimensional (space, time) potential risk of serious adverse health effects. This study investigated the level of toxic metals (Cd and Pb) in 20 Nigerian geophagic clays intended for both local consumption and distribution to the West Africa market. After sampling in 4 open markets in southern Nigeria (Akwa Ibom, Abia, Rivers, Imo), samples were subjected to digestion, ashing and analysis. The Pb levels in all samples exceeded the WHO/FAO maximum permissible limit of 0.1 mg kg^-1 whereas 16% exceeded the Cd limit of 0.3 mg kg^-1. The estimated daily intake of Pb for all samples ranged from 0.0032-0.0286 mg kg_bw^-1 day^-1 to 0.0024-0.0215 mg kg_bw^-1 day^-1 for children and adults, respectively. The estimated daily intakes for Cd ranged from bdl (below detection limit)-0.0010 mg kg_bw^-1 day^-1 to bdl-0.0028 mg kg_bw^-1 day^-1 for children and adults, respectively. In both cases, the WHO/FAO provisional Tolerable Weekly Intake is exceeded through the ingestion of these soils. Our results confirm health risks related to the geophagic practices, its role in exceeding health guidelines when considering aggregate exposure in the Nigerian scenario and body burden in developing organisms, young women, women at fertile age, and pregnant women. We discuss how geophagists consider clays as traditional nutraceuticals and how clarifying the nutraceutical role of geophagy could facilitate risk communication. Geophagic products are implicitly or explicitly marketed as dietary supplements, and as such they should be regulated (1) by labeling, and prohibition of scientifically unfounded health claims and (2) by safety standards before marketing. This is particularly critical when clays originate from countries living rapid, unplanned and uncontrolled development and dumped, like Nigeria.

Broad-Spectrum Antimicrobial and Antibiofilm Activity of a Natural Clay Mineral from British Columbia, Canada

Worldwide increases in antibiotic resistance and the dearth of new antibiotics have created a global crisis in the treatment of infectious diseases. These concerns highlight the pressing need for novel antimicrobial agents. Natural clay minerals have a long history of therapeutic and biomedical applications and have lately received specific attention for their potent antimicrobial properties. In particular, Kisameet clay (KC) has strong antibacterial activity against a variety of multidrug-resistant (MDR) bacterial pathogens in vitro Here, we have extended the known spectrum of activity of KC by demonstrating its efficacy against two major fungal pathogens, Candida albicans and Cryptococcus neoformans In addition, KC also exhibits potent activity against the opportunistic bacterial pathogen Mycobacterium marinum, a model organism for M. ulcerans infection. Moreover, aqueous KC leachates (KC-L) exhibited broad-spectrum antibacterial activity, eradicated Gram-negative and Gram-positive biofilms, and prevented their formation. The mechanism(s) underlying KC antibacterial activity appears to be complex. Adjusting KC-L to neutral pH rendered it inactive, indicating a contribution of pH, although low pH alone was insufficient for its antibacterial activity. Treatment of KC minerals with cation-chelating agents such as EDTA, 2,2'-bipyridyl, and deferoxamine reduced the antibacterial activity, while supplementation of KC-L with these chelating agents eliminated the inhibitory activity. Together, the data suggest a positive role for divalent and trivalent cations, including iron and aluminum, in bacterial inhibition by KC. Collectively, these studies demonstrate the range of KC bioactivity and provide a better understanding of the mechanism underlying its antibacterial effects.IMPORTANCE The escalating emergence of multidrug-resistant (MDR) bacteria, together with the paucity of novel antimicrobial agents in antibiotic development, is recognized as a worldwide public health crisis. Kisameet clay (KC), found in British Columbia (BC), Canada, is a clay mineral with a long history of therapeutic applications among people of the First Nations. We previously reported the antibacterial activity of KC against a group of MDR clinical pathogens. Here, we demonstrate its activity against two major human-pathogenic fungal species, as well as against bacterial biofilms, which underlie many recalcitrant bacterial infections. In these studies, we also identified several geochemical characteristics of KC, such as metal ions and low pH, which are involved in its antibacterial activity. These findings provide a better understanding of the components of KC antibacterial activity and a basis for developing defined preparations of this clay mineral for therapeutic applications.

Investigating the association between stress. Anxiety and geophagy among pregnant women in mwanza, Tanzania

Geophagy, the craving and intentional consumption of soil, is common especially among pregnant women in some low- and middle-income settings. Soils may contain a variety of non-nutritive components such as heavy metals and microbes or substances that interfere with gastrointestinal absorptive processes, posing health risks to pregnant women. Several hypotheses regarding the practice have been proposed but very few have examined the role of maternal stress. The practice of geophagy may help to alleviate stress or anxiety during gestation from perceived dietary or other pregnancy-related concerns. In this study, we evaluated several measures of maternal stress (general anxiety, Pregnancy-Related Anxiety Scores (10-item revised), and Perceived Stress Scores) and other covariates in relation to geophagic behaviour in early pregnancy in 227 women (12-19 weeks gestation) recruited from two hospitals in the Nyamagana district of Mwanza City, Tanzania. Geophagy was reported by 24.7% of the pregnant women. Using LASSO regression, self-reported treatment of nausea or vomiting during pregnancy (adjusted OR = 3.12, 95%CI: 1.43 to 6.83), paternal education level (adjusted OR = 2.79, 95%CI: 1.32 to 5.87 for primary or lower education level), antenatal hospital site (adjusted OR = 3.71, 95%CI: 1.78 to 7.75), prescription drug use prior to pregnancy (adjusted OR = 1.76, 95%CI: 0.87 to 3.56) and general anxiety (feeling worried, tense or anxious in the past four weeks) (adjusted OR = 1.81, 95%CI: 0.88 to 3.72) were associated with geophagic behaviour. Given that relatively little has been done to examine geophagy in relation to the public health risk it may pose to pregnant women, these findings suggest the need for further investigations regarding maternal stress.

Chronic consumption of calabash chalk diet impairs locomotor activities and social behaviour in Swiss white Cd-1 mice

There are safety concerns as regards the consumption of Calabash chalk which is common practice in some localities in Africa and Asia. Calabash chalk contains lead (Pb) and arsenic which are believed to be harmful to the brain and responsible for cognitive dysfunction. It is possible that calabash chalk consumption may affect other neuronal activities in the body such as locomotion and social behaviour. Hence, this present research study investigated the effects of consumption of this diet on locomotion and social behaviour in mice. Forty-five Swiss white mice of mixed sex were randomly assigned into 3 groups of 15 mice each. Group 1 served as control, while groups 2 and 3 received low and high doses of calabash chalk diets respectively. Feeding lasted for 30 days and thereafter their locomotor and social behaviors were assessed. Their locomotor behaviour was assessed using the open field maze while their social behaviour was studied with the aid of nesting behaviour test. Results showed that the calabash chalk diet-fed mice had significantly reduced (p < 0.05) line crossing frequency compared to control. The nesting score of the calabash chalk diet-fed mice was significantly lower (p < 0.05) compared to control. In conclusion, consumption of calabash chalk impairs locomotion and social behaviour in mice.

Effect of "edible clay" (takere) suspension on serum lipid profiles and atherogenic indices of normal Wistar rats

This study was undertaken to ascertain the effect of an aqueous suspension of a commonly available preparation of edible clay ("takere") on serum lipid profiles and atherogenic indices of normal Wistar rats. Ninety-five adult Wistar rats of average weight of 100 g were assigned into seven groups. Group 1 (Baseline) was immediately sacrificed at the commencement of study; Group 2 (Control) daily received distilled water, orally; and Groups 3 to 7 received via the same route (per body weight), 125 mg/kg (T125), 250 mg/kg (T250), 500 mg/kg (T500), 1,000 mg/kg (T1000), and 2,000 mg/kg (T2000) of the takere suspension, respectively, for 28 days. In week 1, the treatments significantly (p < 0.05) lowered the levels of serum triglyceride (by T250, T1000, and T2000), VLDL cholesterol (by T250, T1000, and T2000), and atherogenic index of plasma (AIP; by T250) and significantly (p < 0.05) raised the levels of serum HDL (T250), LDL (T250 and T2000), non-HDL (T2000) cholesterols, atherogenic coefficient (AC; T2000), cardiac risk ratio (CRR; T2000), and Castelli's risk index II (CRI-II; T2000) of the rats. In week 2, the treatments significantly (p < 0.05) lowered the levels of serum triglyceride (T2000), HDL (T125, T500, T1000, and T2000), VLDL (T2000) cholesterols and significantly (p < 0.05) raised levels of serum LDL (T125, T1000, and T2000), non-HDL (T125, T1000, and T2000) cholesterols, AC (T125, T500, and T1000), CRR (T125, T500, and T1000), CRI-II (T125 and T1000), AIP (T125, T500, and T1000) of the rats. In week 4, the treatments significantly (p < 0.05) raised the levels of serum total (T500 and T2000), HDL (T2000), non-HDL (T500 and T1000) cholesterols, AC (T500), CRR (T500), and CRI-II (T500). This result indicates that the consumption of takere suspension may have adverse effects on serum lipid profiles and atherogenic indices of Wistar rats, at least at the doses administered in this study.

Drug-Induced Kidney Stones and Crystalline Nephropathy: Pathophysiology, Prevention and Treatment

Drug-induced calculi represent 1-2% of all renal calculi. The drugs reported to produce calculi may be divided into two groups. The first one includes poorly soluble drugs with high urine excretion that favour crystallisation in the urine. Among them, drugs used for the treatment of patients with human immunodeficiency, namely atazanavir and other protease inhibitors, and sulphadiazine used for the treatment of cerebral toxoplasmosis, are the most frequent causes. Besides these drugs, about 20 other molecules may induce nephrolithiasis, such as ceftriaxone or ephedrine-containing preparations in subjects receiving high doses or long-term treatment. Calculi analysis by physical methods including infrared spectroscopy or X-ray diffraction is needed to demonstrate the presence of the drug or its metabolites within the calculi. Some drugs may also provoke heavy intra-tubular crystal precipitation causing acute renal failure. Here, the identification of crystalluria or crystals within the kidney tissue in the case of renal biopsy is of major diagnostic value. The second group includes drugs that provoke the formation of urinary calculi as a consequence of their metabolic effects on urinary pH and/or the excretion of calcium, phosphate, oxalate, citrate, uric acid or other purines. Among such metabolically induced calculi are those formed in patients taking uncontrolled calcium/vitamin D supplements, or being treated with carbonic anhydrase inhibitors such as acetazolamide or topiramate. Here, diagnosis relies on a careful clinical inquiry to differentiate between common calculi and metabolically induced calculi, of which the incidence is probably underestimated. Specific patient-dependent risk factors also exist in relation to urine pH, volume of diuresis and other factors, thus providing a basis for preventive or curative measures against stone formation.

An analysis of human exposure to trace elements from deliberate soil ingestion and associated health risks

Fifty-seven samples of soils commonly ingested in South Africa, Swaziland, Democratic Republic of Congo (DRC), and Togo were analyzed for the concentrations of arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn) and their bioaccessibility in the human gastrointestinal tract. Bioaccessibility values were used to calculate daily intake, and hazard quotient of each trace element, and chronic hazard index (CHI) of each sample. Carcinogenic risk associated with As and Ni exposure were also calculated. Mean pseudo-total concentrations of trace elements in all samples were 7.2, 83.3, 77.1, 15.4, 28.6, 24.9, 56.1, 2.8, and 26.5 mg/kg for As, Cr, Mn, Co, Ni, Cu, Zn, Cd, and Pb, respectively. Percent bioaccessibility of Pb (13-49%) and Zn (38-56%) were highest among trace elements studied. Average daily intake values were lower than their respective reference doses for ell elements except for Pb in selected samples. Samples from DRC presented the highest health risks associated with trace element exposure with most of the samples having CHI values between 0.5 and 1.0. Some samples had higher than unacceptable values of carcinogenic risk associated with As and Ni exposure. Results indicate low trace element exposure risk from ingesting most of the soil samples.

Health risks from lost awareness of cultural behaviours rooted in traditional medicine: An insight in geophagy and mineral intake

The term geophagy is applied to the recurrent intentional eating of soil with multifactorial motivation. Geophagists are generally defined by gender (women), age (children), physical status (e.g. pregnancy, lactation, postpartum), social status (people exposed to significant nutritional deficiencies), and culture, but lost awareness of traditional medical meaning of this practice is changing these consumption patterns and increasing health risks. Moreover, although the holistic anthropological perspective recognizes soil consumption as mineral supplementation under certain circumstances, we should consider how the living environment has changed and is changing, along with diet, nutrition requirements, and habits. Therefore, benefits-to-risks ratio of cultural behaviours initiated centuries ago based on traditional medical practices requires deep revision and assessment. Knowledge on minerals metabolism, bioavailability and interactions is required to properly assess the role of geophagy in a balanced and safe intake of micronutrients. Most important, the risk of unbalanced intake of minerals may be serious since the mineralogy and chemistry of geophagic clays are uncontrolled, variable, and difficult to standardize. In addition, other factors (radioactive materials, organic chemicals and soil pathogens) complicate the risk assessment for population groups consuming soil. Since the geophagic practice is expected to persist despite economic development, the paper discusses the multifaceted spectrum of geophagy to highlight critical aspects for risk management.

High Prevalence of Opaline Silica in Urinary Stones From Burkina Faso

OBJECTIVE

To underline peculiar composition of kidney stones and to propose an epidemiologic study of urinary stones in West African countries, where epidemiologic studies are scarce. Only few data are available regarding stone composition in sub-Saharan countries. Recently, a set of 100 stones consecutively removed by surgery in the Department of Urology of the University Hospital of Ouagadougou in Burkina Faso were collected for physical analysis, which provided the opportunity to obtain an epidemiologic profile of stone composition in this country.

MATERIALS AND METHODS

A total of 100 stones from 64 men, 22 women, 10 boys, and four girls were analyzed by morphologic examination, infrared spectroscopy, and electron microscopy in our laboratory. The results were considered by sex and separately for adults and children.

RESULTS

Sixty-five percent of the 100 stones contained calcium oxalate as the main component. Interestingly, the second main component was opaline silica (18%). Furthermore, opaline silica was identified in any proportion in 48% of the stones. The prevalence was sex and age dependent. Opaline silica was detected as the main component in 42% of the nuclei, which underlines its role as one of the main components involved in the initiation of calculi in this country.

CONCLUSION

For the first time, a dramatically high occurrence of a "scarce" urinary stone component, namely opaline silica, was reported in a series of consecutive calculi from a single country. We propose that a regular consumption of clay could be the origin of this phenomenon in these populations.

Maternal Geophagy of Calabash Chalk on Foetal Cerebral Cortex Histomorphology

BACKGROUND

Calabash chalk, a kaolin-base substance is a common geophagic material mostly consumed by pregnant women. This study investigated its effect on the histomorphology of the foetal cerebral cortex.

METHODS

Twelve gestating Wistar rats were divided equally into groups 1 and 2. On pregnancy day seven (PD7), group 2 animals were administered 200 mg/kg body weight of calabash chalk suspension, while group 1 animals served as the control and received 1 ml of distilled water, by oral gavages and for 14 days (PD7-PD20). On PD21, the dams were sacrificed, and the foetuses removed, examined for gross malformations, weighed and culled to two foetuses per mother. Their whole brains were excised, weighed and preserved using 10% buffered formalin, and routinely processed by haematoxylin and eosin, and Luxol fast blue methods.

RESULTS

The foetuses showed no morphological change, but their mean body weights was higher (p=0.0001). Histomorphological sections of the cerebral cortex showed hypertrophy and hyperplasia of cells in all the cortical layers, with less demonstrated Nissl and higher (p=0.001) cellular population compared with the control group.

CONCLUSION

Calabash chalk cause body weight increase and histomorphological changes in the cerebral cortex of foetuses.

Highly sensitive detection of chromium (III) ions by resonance Rayleigh scattering enhanced by gold nanoparticles

Simple and sensitive determination of chromium (III) ions (Cr(3+)) has potential applications for detecting trace contamination in environment. Here, the assay is based on the enhancement of resonance Rayleigh scattering (RRS) by Cr(3+)-induced aggregation of citrate-capped gold nanoparticles (AuNPs). Transmission electron microscopy (TEM) and UV-vis absorption spectroscopy were employed to characterize the nanostructures and spectroscopic properties of the Cr(3+)-AuNP system. The experiment conditions, such as reaction time, pH value, salt concentration and interfering ions, were investigated. The combination of signal amplification of Cr(3+)-citrate chelation with high sensitivity of RRS technique allow a selective assay of Cr(3+) ions with a detection limit of up to 1.0 pM. The overall assay can be carried out at room temperature within only twenty minutes, making it suitable for high-throughput routine applications in environment and food samples.