1.
The Role of Iron in Brain Development: A Systematic Review.
McCann, S, Perapoch Amadó, M, Moore, SE
Nutrients. 2020;12(7)
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Iron deficiency is the most common vitamin or mineral deficiency worldwide and is particularly common among pregnant women, infants and young children due to high iron demands during periods of rapid growth. Iron plays an important role in the development of the brain, and animal studies suggest that getting enough iron in pregnancy and early childhood is particularly important. The aims of this systematic review were to (i) investigate the relationship between iron status and brain development and (ii) assess whether this relationship differs according to age or type of development (‘domain’). The researchers looked for studies on iron deficiency or iron supplementation in pregnancy and up to 4 years of age. 26 observational studies and 28 intervention studies were included in the review. There was no clear relationship between iron status and developmental outcomes across any of the ages or domains included. Many of the studies were of low quality and there was a wide variation in study design, along with a lack of research on pregnancy and early infancy. The researchers concluded that evidence for the impact of iron deficiency or iron supplementation on early development is inconsistent. Further high-quality research is needed, particularly within pregnancy and early infancy, which has previously been neglected.
Abstract
One-third of children falter in cognitive development by pre-school age. Iron plays an important role in many neurodevelopmental processes, and animal studies suggest that iron sufficiency in pregnancy and infancy is particularly important for neurodevelopment. However, it is not clear whether iron deficiency directly impacts developmental outcomes, and, if so, whether impact differs by timing of exposure or developmental domain. We searched four databases for studies on iron deficiency or iron supplementation in pregnancy, or at 0-6 months, 6-24 months, or 2-4 years of age. All studies included neurodevelopmental assessments in infants or children up to 4 years old. We then qualitatively synthesized the literature. There was no clear relationship between iron status and developmental outcomes across any of the time windows or domains included. We identified a large quantity of low-quality studies, significant heterogeneity in study design and a lack of research focused on pregnancy and early infancy. In summary, despite good mechanistic evidence for the role of iron in brain development, evidence for the impact of iron deficiency or iron supplementation on early development is inconsistent. Further high-quality research is needed, particularly within pregnancy and early infancy, which has previously been neglected.
2.
Respiratory and Allergic Effects in Children Exposed to Pesticides-A Systematic Review.
Buralli, RJ, Dultra, AF, Ribeiro, H
International journal of environmental research and public health. 2020;17(8)
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Agricultural pesticides are harmful chemicals used to protect plants from pests and diseases. There has been previous research showing a link between pesticide usage and respiratory symptoms, asthma, allergies, and lung function irregularities in children. To evaluate the relationship between pesticide usage and allergic and respiratory effects in children, 21 studies were included in this systematic review. This systematic review reports an association between multiple sources of pesticide exposure during fetal and early development and respiratory symptoms and allergies among children. Compared to high-income countries, children in the middle- and low-income countries were exposed to multiple pesticide sources. As current scientific evidence is sparse, more research is needed to determine the causal relationship between pesticides and respiratory and allergic symptoms in children. Robust research in low- and middle-income countries is necessary. Healthcare professionals can use the results of this study to understand the harmful effects of pesticide exposure in children and to take clinical decisions to reduce the exposure and its effects.
Abstract
Pesticide exposure may affect children's respiratory and allergic health, although results from epidemiological studies have not reached consensus. This review aims to analyze the scientific evidence on respiratory and allergic effects of exposure to agricultural pesticides in children aged up to 12 years old. The databases PubMed, Web of Science, Scielo, and Lilacs were screened to select articles published in English, Spanish, or Portuguese, and 21 articles were included in this review. Most investigations were conducted in North America (mostly in the United States), while no studies conducted in Latin America or Africa were found, despite their intensive use of pesticides. Children are exposed to pesticides through multiple pathways from the prenatal period throughout later developmental stages and may experience several respiratory effects. Most studies (79%) found positive associations with pesticide exposure and children's respiratory and allergic effects such as asthma, wheezing, coughs, acute respiratory infections, hay fever, rhinitis, eczema, chronic phlegm, and lung function impairments. Contrastingly, 21% of the studies found no associations between pesticide exposure and children's respiratory health. The vast differences among the characteristics of the studies hamper any comparison of the results. Exposure to pesticides may have several impacts on childhood respiratory health. More studies must be conducted, especially in low- and middle-income countries, preferably with comparable research protocols adapted to local realities. Efforts should be made to develop comprehensive risk mitigation strategies and behavioral interventions to reduce children's exposure to pesticides used in agriculture and respiratory health effects, and to ensure healthy childhood growth.