Nutrition

 

Much of the global burden of disease is related to inadequate intake of calories, micronutrients, or certain food groups like fruits, vegetables, meats, nuts, and seeds. Additional burden of disease is associated with excessive intake of the wrong foods. Global food demand has never before increased more rapidly, and the biophysical conditions that underpin our global food production system have never been changing so rapidly. As a result, humanity is enormously vulnerable to health impacts from environmental change mediated through changing access to nutrition.

Learning Objectives

  • L1: Describe sociocultural, economic and environmental impacts on human nutrition.
  • L2: Explore the relationship between land use, agriculture and health.
  • L3: Examine human food production and consumption patterns in comparison with demographic shifts.

 

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Yakoob, M Y, Theodoratou E, Jabeen A, Imdad A, Eisele, T P, Ferguson J, Jhass A, Rudan I, Campbell H, Black RE. Preventive zinc supplementation in developing countries: impact on mortality and morbidity due to diarrhea, pneumonia and malaria. BMC Public Health [Internet]. 2011;11 Suppl 3 :S3-S23. Publisher's VersionAbstract

Background

Zinc deficiency is commonly prevalent in children in developing countries and plays a role in decreased immunity and increased risk of infection. Preventive zinc supplementation in healthy children can reduce mortality due to common causes like diarrhea, pneumonia and malaria. The main objective was to determine all-cause mortality and cause-specific mortality and morbidity in children under five in developing countries for preventive zinc supplementation.

Data sources/ review methods

A literature search was carried out on PubMed, the Cochrane Library and the WHO regional databases to identify RCTs on zinc supplementation for greater than 3 months in children less than 5 years of age in developing countries and its effect on mortality was analyzed.

Results

The effect of preventive zinc supplementation on mortality was given in eight trials, while cause specific mortality data was given in five of these eight trials. Zinc supplementation alone was associated with a statistically insignificant 9% (RR = 0.91; 95% CI: 0.82, 1.01) reduction in all cause mortality in the intervention group as compared to controls using a random effect model. The impact on diarrhea-specific mortality of zinc alone was a non-significant 18% reduction (RR = 0.82; 95% CI: 0.64, 1.05) and 15% for pneumonia-specific mortality (RR = 0.85; 95% CI: 0.65, 1.11). The incidence of diarrhea showed a 13% reduction with preventive zinc supplementation (RR = 0.87; 95% CI: 0.81, 0.94) and a 19% reduction in pneumonia morbidity (RR = 0.81; 95% CI: 0.73, 0.90). Keeping in mind the direction of effect of zinc supplementation in reducing diarrhea and pneumonia related morbidity and mortality; we considered all the outcomes for selection of effectiveness estimate for inclusion in the LiST model. After application of the CHERG rules with consideration to quality of evidence and rule # 6, we used the most conservative estimates as a surrogate for mortality. We, therefore, conclude that zinc supplementation in children is associated with a reduction in diarrhea mortality of 13% and pneumonia mortality of 15% for inclusion in the LiST tool. Preventive zinc supplementation had no effect on malaria specific mortality (RR = 0.90; 95% CI: 0.77, 1.06) or incidence of malaria (RR=0.92; 95 % CI 0.82-1.04)

Conclusion

Zinc supplementation results in reductions in diarrhea and pneumonia mortality.

Caulfield LE, Richard SA, Rivera JA, Musgrove P, Black RE. Stunting, Wasting, and Micronutrient Deficiency Disorders. In: ; 2002. Publisher's VersionAbstract

Undernutrition and micronutrient deficiencies contribute substantially to the global burden of disease (Ezzati and others 2002). Impoverished communities experience high rates of undernutrition and increased exposure to infectious diseases caused by crowding and inadequate sanitation. Women of reproductive age and children experience devastating health consequences as a result of limited resources, cultural influences, and biological vulnerabilities. Undernutrition and infectious diseases exist in a baleful synergy: undernutrition reduces immunological capacity to defend against diseases, and diseases deplete and deprive the body of essential nutrients. Undernutrition and infectious diseases further exacerbate poverty through lost wages, increased health care costs, and—most insidiously—impaired intellectual development that can significantly reduce earning potential. Health experts have recently recognized the long-term effects of early undernutrition and inadequate infant feeding for obesity and chronic diseases, including diabetes and cardiovascular diseases. This chapter summarizes the problems of undernutrition and vitamin A, iron, zinc, and iodine deficiencies in young children and current programmatic efforts to prevent and treat them.

Loladze I. Hidden shift of the ionome of plants exposed to elevated CO2 depletes minerals at the base of human nutrition. eLife [Internet]. 2014. Publisher's VersionAbstract

Mineral malnutrition stemming from undiversified plant-based diets is a top global challenge. In C3plants (e.g., rice, wheat), elevated concentrations of atmospheric carbon dioxide (eCO2) reduce protein and nitrogen concentrations, and can increase the total non-structural carbohydrates (TNC; mainly starch, sugars). However, contradictory findings have obscured the effect of eCO2 on the ionome—the mineral and trace-element composition—of plants. Consequently, CO2-induced shifts in plant quality have been ignored in the estimation of the impact of global change on humans. This study shows that eCO2 reduces the overall mineral concentrations (−8%, 95% confidence interval: −9.1 to −6.9, p<0.00001) and increases TNC:minerals > carbon:minerals in C3 plants. The meta-analysis of 7761 observations, including 2264 observations at state of the art FACE centers, covers 130 species/cultivars. The attained statistical power reveals that the shift is systemic and global. Its potential to exacerbate the prevalence of ‘hidden hunger’ and obesity is discussed.

Balk D, Storeygard A, Levy M, Gaskell J, Sharma M, Flor R. Child hunger in the developing world: An analysis of environmental and social correlates. Food Policy [Internet]. Submitted;30 :584-611. Publisher's VersionAbstract

Using two complementary methods in a framework that allows incorporating both environmental and household-level factors, we explore the correlates of underweight status among children. We use individual children as the units of analysis in 19 African countries, and subnational survey strata in 43 African, Asian and Latin American countries. We consider the relationship between household-level demographic and health survey data, environmental factors from external geospatial data sets and two indicators of malnutrition among children aged 1–3, deviations from the international standards of weight-for-age and height-for-age. We discuss methods for data integration. In general, household determinants explain more variation than environmental factors, perhaps partly due to more error-prone measurement at the community level. Among individual children, some measures of agricultural capacity are related to lower incidence of child hunger, while among regions, measures relating to urbanness and population density show a stronger relationship. We give recommendations for further study, data collection and policy making.

Fu W, Ding, L R, Zhuang C, Zhou, Y H. Effects of zinc supplementation on the incidence of mortality in preschool children: a meta-analysis of randomized controlled trials. PLoS ONE [Internet]. 2013;8. Publisher's VersionAbstract

BACKGROUND: Previous trials have shown that zinc supplementation can decrease the risk of diarrheapneumonia, and malaria in children; however, the effects of zinc supplementation on mortality remain unclear. This study aimed at evaluating the benefits and risks of zinc supplementation on both total mortality and cause-specific mortality.

METHODOLOGY AND PRINCIPAL FINDINGS: We searched PubMed, EmBase, and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials in preschool children reporting total mortality or cause-specific mortality. Relative risk (RR) was used as a measure of the effect of zinc supplementation on the risk of mortality using a random effect model. Of the 1,520 identified articles, we included 8 trials reporting data on 87,854 children. Overall, zinc supplementation had no effect on total mortality (RR, 0.76; 95% CI: 0.56-1.04; P = 0.084), diarrhea-related mortality (RR, 0.80; 95% CI: 0.53-1.20; P = 0.276), pneumonia-related mortality (RR, 0.52; 95% CI: 0.11-2.39; P = 0.399), malaria-related mortality (RR, 0.90; 95% CI: 0.77-1.06; P = 0.196), or other causes of mortality (RR, 0.98; 95% CI: 0.67-1.44; P = 0.917). Subgroup analysis indicated that zinc supplementation was associated with a reduction in total mortality risk if the participants were boys, aged greater than 12 months, and the duration of the follow-up period was less than 12 months.

CONCLUSIONS/SIGNIFICANCE: Zinc supplementation does not have an effect on total mortality, diarrhea-related mortality, pneumonia-related mortality, malaria-related mortality, or other causes of mortality. Subgroup analysis suggested that zinc supplementation can effectively reduce the risk of total mortality if the participants were boys, aged greater than 12 months, and the duration of the follow-up period was less than 12 months.

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