A meta‐analysis of pica and micronutrient status

Abstract

Objectives Pica is the craving for and consumption of non-food items, including the ingestion of earth (geophagy), raw starch (amylophagy), and ice (pagophagy). Pica has long been associated with micronutrient deficiencies, but the strength of this relationship is unclear. We aimed to evaluate the association between pica behavior and the risk of being anemic or having low hemoglobin (Hb), hematocrit (Hct), or plasma zinc (Zn) concentrations. Methods We systematically reviewed studies in which micronutrient levels were reported by pica status. We calculated the pooled odds ratio for anemia or weighted mean difference in Hb, Hct, or Zn concentrations between groups practicing or not practicing pica behaviors. Results Forty-three studies including 6407 individuals with pica behaviors and 10,277 controls were identified. Pica was associated with 2.4 times greater odds of anemia (95% CI: 1.94–2.85, p<0.001), lower Hb concentration (−0.65 g/dL, 95% CI: −0.83–−0.48 g/dL, p<0.001), lower Hct concentration (−1.15%, 95% CI: −1.61–−0.70%, p<0.001), and lower Zn concentration (−34.3 μg/dL, 95% CI: −59.58–−9.02 μg/dL, p=0.008). Statistical significance persisted after excluding outliers and in subgroup analyses by pica type and life stage. Conclusions Pica is significantly associated with increased risk for anemia and low Hb, Hct, and plasma Zn. Although the direction of the causal relationship between pica and micronutrient deficiency is unknown, the magnitude of these relationships is comparable to other well-recognized causes of micronutrient deficiencies. Pica warrants greater public health attention; specifically a potential physiological mechanism causing the relationship between pica and micronutrient deficiencies merits further study.

The relation between pica and iron deficiency in children in Zanjan, Islamic Republic of Iran: a case-control study

“…In the observed population pica was not regarded as stigmatized culture, rather a divergent behaviour (20). In studies from the United States of America the prevalence of pica in children ranged between 10.0% and 18.5% (7,10). The differences may be explained by the distinct definitions of pica and the parents' unwillingness to declare their child's behaviour abnormal.…”

“…These findings differ from those of some other studies (3,19,23,24). But at least 2 double blind controlled studies did not find any relationship between iron therapy and pica behaviour (10). This is probably because pica is more a cultural behaviour than a result of iron deficiency.…”

“…The frequency of pica varies from place to place, however, it appears to be more common in children, women, black people, people residing in rural areas and pregnant women (9). Its frequency in the United States of America ranges from 4% among men to 68% in pregnant women and 18.5% in children (10).…”

Geophagy is Associated with Environmental Enteropathy and Stunting in Children in Rural Bangladesh

“…45,46 A recent meta-analysis found that pica was significantly associated with an increased risk for anemia and low hemoglobin, hematocrit, and plasma zinc. 27 However, there are no published studies that we are aware of that have been able to establish a causal relationship between geophagy and micronutrient status. Two randomized controlled trials conducted to determine the impact of iron supplementation on geophagy in children found no significant reduction in geophagy behavior among study children with supplementation.…”

“…[23][24][25][26] Furthermore, these findings suggest that geophagy may be a potential risk factor for EE and stunting in pediatric populations. However, there are very few published studies assessing geophagy in pediatric populations, [23][24][25][26][27] and none assessing the role of this behavior in EE or stunting.…”