Diarrhoea and malnutrition interaction.
Epidemiological studies have demonstrated a marked negative relationship between diarrhoea and physical growth and development of a child. Each day of . The relentless cycle of malnutrition and diarrhea places Among children who survive severe diarrhea, chronic infections can contribute to malnutrition. In turn. Diarrhea and malnutrition, alone or together, constitute major causes of morbidity and mortality among children throughout the tropical world. Data from.
In one longitudinal study, estimates of the potential impact of exclusive breastfeeding on rates of diarrhea during the first 6 months of life showed that interventions that successfully motivate adoption of this feeding practice could dramatically reduce infant morbidity. Continued breastfeeding for more than 6 months, although not practiced exclusively, was still associated with reduced risk of illness.
The protective effect of breastfeeding may be explained by reduced exposure to fecally contaminated foods and feeding utensils or by the anti-infective components of breast milk.
Also, growth factors that are present in human milk may hasten intestinal mucosal renewal and recovery from enteric infections. The benefit provided by breastfeeding was of greater magnitude for diarrheal prevalence than for incidence Brown et al. This suggests that breastfeeding not only lessens the risk of new illnesses but also shortens the duration of those illnesses that occur.
This phenomenon might be explained by the ingestion of a smaller infectious dose of pathogens by more Page 27 Share Cite Suggested Citation: In one clinical study, stool volume was reduced among breastfed infants with diarrhea compared with that among infants whose breastfeeding was discontinued during the early phase of therapy; these observations suggest that breast milk itself may reduce the severity of illness and hasten recovery Khin-Maung-U et al.
Nonetheless, data presented in favor of human milk's direct protective effects are disputed because of confounding environmental and demographic variables that are difficult to control Bauchner et al. Each of these variables is a potential determinant of morbidity.
Protective Factors in Human Milk Three mechanisms have been proposed by which human milk constituents directly protect the infant from infection. Two are based on the immunologic factors in human milk, and the third is based on human milk's high nutritive value.
The relative protective contributions of human milk's immunologic and nutrient constituents are difficult to estimate. Potentially protective proteins in human milk can be classified into antigen-specific and non-antigen-specific agents. They have been the subject of numerous reviews Goldman and Goldblum, ; Welsh and May, The major functioning important whey proteins are lactoferrin and sIgA.
Lactoferrin is a non-antigen-specific factor. It binds iron avidly, and thereby presumably limits iron availability to bacteria Griffiths and Humphreys, Lactoferrin may also modulate inflammatory responses by inhibiting complement Goldman et al.
Secretory IgA is the major antigen-specific component in human milk Specific activity against a wide array of enteric and respiratory bacterial and viral pathogens is found in human milk Goldman and Goldblum, The attachment of sIgA to the glycocalyx of epithelial cells in the microvilli of the small intestine may block the attachment to the intestinal tract by infectious agents Nagura et al.
The concentrations of most immunologically active proteins appear to fall after the first 2 or 3 months of lactation and subsequently either rise e. Immunoprotein concentrations generally rise or remain constant after the onset of gradual weaning Goldman et al.
Growth factors also have been identified in human milk Klagsbrun, ; Moran et al. These factors may promote the maturation of the infant's gastrointestinal epithelium, and thereby augment mucosal barriers against the penetration of the gastrointestinal tract by antigens. The relationships among breastfeeding, specific anti-pathogen activities in human milk, and specific enteric illnesses have not been examined completely.
Breastfeeding appears to ameliorate shigellosis Mata et al. Although the evidence is mixed, rotaviral diarrhea appears to be milder in breastfed infants, and not all anti-rotaviral activity is associated with specific antigenic properties Duffy et al. Cholera and infections with Giardia lamblia are less likely in infants of women with high titers of specific sIgA in their milk Glass et al. Lactation Performance The enhancement of lactation performance is expected to minimize the need for supplementary foods to meet the nutrient requirements of infants and to maximize the protection afforded in the practice of breastfeeding and the immunologic constituents of human milk.
Available studies suggest that milk volume is more sensitive to maternal nutritional status than is milk composition Garza and Butte, Most studies have focused on total nitrogen, lactose, and fat.
Nonbehavioral maternal and environmental factors that may influence the duration of lactation also have received limited attention. Generally, the fatty acid composition and the concentrations of the fat-and water-soluble vitamins of milk are affected most by diet. Protein concentrations are influenced by selected dietary conditions, but the effects appear to be relatively limited.
Lactose, mineral, trace element, and electrolyte concentrations appear to be relatively resistant to wide variations in maternal intakes. Page 29 Share Cite Suggested Citation: Longitudinal studies of poorly nourished, lactating Bangladeshi mothers from an underprivileged, periurban community demonstrated that average milk production and fat and energy concentrations in milk were similar to those described for well-nourished women.
Fat and energy concentrations in milk and the amounts produced per day were greater in women with larger triceps skinfold thickness, or arm circumference; and increases in body weight were associated with increases in the amounts of milk and all macronutrients produced.
Diarrhoea and malnutrition interaction.
Milk production, however, declined significantly before the major harvest period, when food was least available Brown et al. Women who delivered low-birthweight infants produced insufficient milk volumes by 2 months postpartum. This and other similar studies, however, are complicated by the early return of women to work outside the home whereby the frequency of breastfeeding must be reduced or breastfeeding must be stopped entirely.
The effects on lactation performance of superimposing high levels of activity on a woman with a marginal nutritional status were investigated in The Gambia. Breast milk composition remained relatively stable through an periods of the year, but breast milk output was minimal during the farming season, when activity was highest.
Reductions in milk output of up to 10 percent were observed in mothers 3 to 12 months postpartum who kept their infants with them while they worked outside the home; reductions of 25 percent were seen in mothers who were separated from their older infants during the work day Roberts et al.
Impaired lactation performance may result from heightened activity, shortfalls in nutrient intakes during periods of intense work, or maternal and infant separation. The mother's dietary protein, carbohydrate, and fat intake apparently has no detectable impact on milk quantity. Milk fat composition is influenced by dietary fat. Most studies of well-nourished women report no significant interactions between milk quantity and quality and maternal weight, height, metabolic size, body surface area, change in body fat, prepregnancy weight, and weight gain during pregnancy Butte et al.
Page 30 Share Cite Suggested Citation: The body of information neither supports nor refutes a positive effect from this type of intervention. Failure to control complex intervening variables in supplemental trials accounts substantially for the present state of knowledge.
Variations in the degree of malnutrition or undernutrition, differences in the quantity and quality of the supplement used, the difficulty in measuring compliance, the possibility that the supplement is used to replace rather than augment dietary intake, and the wide variability in protocols make available studies difficult to evaluate. Differences in the milk yield of supplemented and unsupplemented women were noted, but only from the third month postpartum on.
After that time, the supplemented group produced 30 percent more milk than control women Girija et al. Studies in animals also have shown a positive influence of supplements during lactation. Not all studies, however, have concluded that improvements in maternal intakes lead to enhanced milk production.
No changes in milk production were detected Prentice et al. Data from protein supplementation trials published by Edozien et al. The specificity of protein for increasing milk volume, however, is not certain. Gopalan attempted to control one confounding variable, energy intake. A positive effect on milk volume was reported with protein supplementation.
Manipulation of Immunologic Protein Factors in Human Milk Maternal nutritional status appears to influence the concentrations and total amounts of immunologically active proteins produced in human milk, but available data are inconsistent.
Some studies report decreases in the concentrations of immunological protein in the milk of undernourished women Miranda et al. Nevertheless, the significant reductions in milk volume that are expected with maternal undernutrition would reduce the protective effects of human milk if the efficacy of immunological proteins is dose-related.
No effective means of enhancing the concentrations of nonspecific protective components in human milk have been identified. While the specificity of sIgA in human milk depends on the mother's antigenic exposure, the mechanism responsible for the presence of specific sIgA in human milk is understood only partially, and a successful strategy for the enhancement of specific sIgA levels directed against enteric pathogens has not been demonstrated in humans.
WEANING FOODS Following the period during which exclusive breastfeeding can support adequate growth, improvement in the nutritional status of target populations through feeding interventions requires the timely introduction of nutritious complementary foods and improved dietary therapy of common childhood illnesses. Planning each of these interventions requires, in turn, knowledge of locally available foods; the nutritional content and quality of these foods; and the social, economic, cultural, and seasonal constraints to their appropriate use under different circumstances.
Nutrient Composition of Common Foods The nutrient compositions of foods can be measured by standard analytic techniques and are usually expressed per unit weight of raw edible portions. Although the data base for food composition is constantly expanding, information is currently available primarily for macronutrients protein, fat, and carbohydratetotal metabolizable energy ''calories''and selected vitamins and minerals Rand, Additional tables of amino acid content, carbohydrate profiles sugars, starches, and nonstarch polysaccharides or fiberfatty acid composition, and trace element concentrations of limited numbers of foods are also becoming available or are under development.
Diarrhea and Malnutrition | The Journal of Nutrition | Oxford Academic
Food composition tables have been prepared for different regions of the world. These composition tables consider locally available and commonly consumed products. Unfortunately only small numbers of samples have been analyzed for each type of food, and it has been found that the nutrient compositions of individual foods vary greatly. The major nutrient sources are 1 the staple foods, which provide the majority of energy and protein as well as some vitamins and minerals; 2 fruits and vegetables, which are important additional sources of vitamins and minerals; 3 animal products, which can supplement the amount and quality of dietary protein, specific vitamins, and minerals; and 4 fats, oils, and sugars, which can enhance the energy density of mixed diets.
The staple foods include cereals, such as wheat, rice, maize, and millet; roots and tubers, such as white potatoes, sweet potatoes, yams, and cassavas; and pulses or legumes, such as peas, beans, and groundnuts. Cereals are composed mostly of carbohydrate primarily starch and nonstarch polysaccharidesprotein at a level between 6 and 14 percent of dry weightand little fat.
Nutrients are not distributed equally throughout the anatomic structures of grains, so the final nutrient composition of a cereal product depends on the degree of milling and other types of food processing see Chapter 5. The outer layers of the grain contain relatively higher concentrations of protein, vitamins, and fiber, whereas the endosperm is generally higher in starch.
The germ is relatively rich in protein, fat, and some vitamins. The water-soluble vitamins of the husk can be partially transferred to the endosperm by parboiling, which also improves the storage characteristics of the grain. Cereals are important quantitative sources of protein, but their protein quality is limited by the inadequate content of selected essential amino acids WHO, Tubers, like cereals, have a high starch content and may contain reasonably good levels of protein.
However, the water content of unprocessed roots and tubers is substantially greater than that for cereals. While the concentration of nutrients per unit of raw weight of tubers is lower than that for cereals, the ratio of protein to energy for some tubers, such as white potatoes, may be similar to that for some cereals. On the other hand, cassava is very low in protein, and the limited amount of protein it contains is of poor quality.
The most recent phase of research on this theme has begun to examine the effect of diarrhea on micronutrient balance and assessment of micronutrient status. For example, Castillo-Duran et al. Nutritional risk factors for diarrhea Nutritional risk factors for diarrhea can be grouped as anthropometric risk factors, infant and child feeding practices and micronutrient status.
Measures of resulting morbidity from diarrhea include both incidence rates and the duration and severity of illness. Research on these issues is summarized in the time line presented in Figure 4. Studies by James et al.
Although most investigators accept the conclusion that malnutrition increases the risk of diarrhea, it must be recognized that the design of these descriptive epidemiological studies does not permit elimination of the possibility that confounding factors may explain as least some of the observed results. For example, researchers have noted the possibility that children with some underlying predisposition to enteric infection, such as environmental exposures or immunodysfunction, may have become undernourished because of earlier illnesses.
Thus, baseline malnutrition, as defined by anthropometric indicators, may have been a result of these prior illnesses rather than a cause of subsequent ones. Disentanglement of the causal sequence of these events has remained problematic.
During this same period of time, investigators also described associations between anthropometric indicators of nutritional status and the duration of illness 18the severity of fecal purging 19 and, most important, the case-fatality rates In each case, preexisting malnutrition was associated with an increased severity of diarrheal disease.
Infant feeding practices is another nutrition-related risk factor that received heightened attention during the period after Two important studies published from Latin America and Asia at the end of the s found that exclusively breastfed infants had considerably reduced risks of diarrhea and other infections compared with infants who either received other foods or liquids along with breast milk or were fully weaned from the breast 2122 ; and similar results have been published more recently from more industrialized settings During the s and s researchers began to question whether deficiencies of specific micronutrients might also affect the risk of diarrhea.
Studies were beginning to emerge that indicated that the risk of mortality was reduced in children who had received large doses of vitamin A Because most childhood deaths in low income settings are attributable to infection, it was reasonable to assume that this effect of vitamin A might be attributable to a reduced incidence of infections.
Despite the apparent logic of this assumption, most studies of this relationship found no effect of vitamin A supplementation on the incidence of diarrhea 25 However, researchers in Ghana clarified this issue when they discovered that clinic visits and hospital admissions for diarrhea were decreased in vitamin A-supplemented children, even though diarrheal incidence rates remained unchanged Thus, it appeared that vitamin A reduced the severity of illness without affecting the overall attack rate.
More recently, several groups of investigators have pursued studies of the effect of zinc supplementation on the risk of diarrhea 28 Dietary management of patients with diarrhea In response to the growing recognition that diarrhea undermines nutritional status, a number of investigators began to reexamine the prevailing approaches to the dietary management of these patients, as summarized in Figure 5. In researchers from Peru published the results of a randomized, clinical trial to assess the optimal approach for the initial dietary management of children with acute diarrhea and dehydration