Submitted to: Current Opinion in Clinical Nutrition and Metabolic Care
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2008
Publication Date: 10/1/2008
Citation: Scrimgeour, A.G., Lukaski, H.C. 2008. Zinc and Diarrheal Disease - Control Status and Future Perspectives. Current Opinion in Clinical Nutrition and Metabolic Care.1:711-717 Interpretive Summary: Diarrhea persists as a major, international public health problem with approximately 1.5 billion episodes annually, particularly among children in developing countries but also among older adults. Although mortality due to diarrheal illness has declined dramatically with use of oral glucose-electrolyte rehydration fluid, it occurs in more than 2 million people annually. Diarrhea also causes major losses of nutrients and can lead to malnutrition. Adequate zinc intake is needed to support many aspects of immune function against infection and the maintenance of function in the intestines. Specifically, zinc acts to inhibit the excessive loss of fluid, chloride, potassium, magnesium, and other minerals into the large intestine that cause diarrhea. Findings from studies of children with acute and persistent diarrhea caused by various pathogens including parasites, bacteria and viruses emphasize that zinc is useful in reducing the duration and severity of single episode and recurrent bouts of diarrhea. Antibiotics can be helpful in treating diarrhea. Factors such as increasing resistance to available antibiotics and the lack of effective anti-diarrheal vaccines emphasize the benefit of oral zinc supplementation because it reduces stool output and duration of diarrhea symptoms. Safety, selectivity of action and low cost favor the use of oral zinc supplementation for the treatment of diarrheal diseases in children. Clinical trials of the efficacy of oral zinc supplementation in adults with diarrhea are needed. This information will be useful to public health nutritionists who work in areas where diarrhea is endemic and other areas in which marginal zinc deficiency can be expected.
Technical Abstract: Diarrhea is a public health problem world-wide. Although elimination of exposure to infectious pathogens is the primary means to combat this debilitating malady, use of oral zinc supplementation has been used to prevent and treat acute diarrhea in children. Evidence suggests that supplemental zinc also may be useful as an anti-diarrheal agent in adults. Zinc plays an important role in modulating host resistance to infectious agents and reducing the risk, severity, and duration of diarrheal-diseases. Zinc is important in the developing world, and in low- and middle-income countries where mild-to-moderate zinc deficiency is highly prevalent. Children and the elderly living in industrialized countries can be susceptible to moderate-zinc deficiency. Recommendations for zinc supplementation from the World Health Organization are based on meta-analyses of randomized, controlled intervention trials in children: daily 20 mg zinc supplements for 10–14 days for children with acute diarrhea, and 10 mg per day for infants under six months old. Water-soluble zinc salts in the form of sulfate, gluconate, or acetate are recommended for prevention and therapy. No clinical studies have been conducted in adults. Thus, carefully conducted clinical trials are necessary to ascertain the efficacy of supplemental zinc in the prevention of acute and persistent diarrhea in adults. The outcomes of such trials can lead to improved quality of life and economic benefits for the affected populations.