Micronutrient deficiencies: public health implications

Operational feasibility of implementing community-based zinc supplementation: impact on childhood diarrheal morbidity

OBJECTIVE

To determine the effect of zinc supplementation on diarrheal incidence and to discover any operational constraints of zinc supplementation at the community level.

METHODS

We included 1712 children aged between 6 and 48 months in a randomized double blind study in rural area comprising of 11 villages. Children were randomly divided into 2 groups. Zinc/placebo syrup supplementation was continued for 6 months in a weekly schedule from May 2003. Children were followed up weekly for detection of diarrhea from May 2003 until April 2004. Around 30% of the study children were evaluated every 2 months during supplementation period.

RESULTS

During the period, 80,534 weekly visits were made giving 1548.73-child years of observation. We detected 1438 diarrheal episodes among 846 children. The incidence of diarrhea was significantly less during the supplemented period (P < 0.001; RR 0.74 (0.64-0.87)) in the zinc group. A significant difference was also noted during the follow up period (P < 0.05). In the zinc group, children <2 years of age had significantly less diarrhea during supplementation and the follow up period. Multiple episodes of diarrhea (>or=2) were significantly less in the zinc group. Approximately 85% of the surveillance workers made weekly visits to the houses and 96% of mothers administered syrup weekly to their children. Around 80% of mother's were aware of the possible benefits of zinc supplementation.

CONCLUSION

Weekly zinc supplementation was effective in reducing diarrheal morbidity at the community level and it was operationally feasible.

Treatment of infectious diarrhea in children

Diarrheal diseases remain an important cause of childhood morbidity and death in developing countries, although diarrheal deaths have significantly declined in recent years, mostly due to successes in the implementation of oral rehydration therapy (ORT), which is the principal treatment modality. Diarrhea may occur for varied reasons; however, most episodes of diarrhea in developing countries are infectious in origin. Three clinical forms of diarrhea (acute watery diarrhea, invasive diarrhea, and persistent diarrhea) have been identified to formulate a management plan. Acute diarrhea may be watery (where features of dehydration are prominent) or dysenteric (where stools contain blood and mucus). Rehydration therapy is the key to management of acute watery diarrhea, whereas antimicrobial agents play a vital role in the management of acute invasive diarrhea, particularly shigellosis and amebiasis. In persistent diarrhea, nutritional therapy, including dietary manipulations, is a very important aspect in its management, in addition to rehydration therapy. Rehydration may be carried out either by the oral or intravenous route, depending upon the degree of dehydration. Oral rehydration salts (ORS) solution (World Health Organization formula) is recommended for ORT. Intravenous fluid is recommended for initial management of severe dehydration due to diarrhea, followed by ORT with ORS solution for correction of ongoing fluid losses. Antimicrobial therapy is beneficial for cholera and shigellosis. Antiparasitic agents are indicated only if amebiasis and giardiasis are present. Appropriate feeding during diarrhea is recommended for nutritional recovery and to prevent bodyweight loss. Antidiarrheal agents do not provide additional benefit in the management of infectious diarrhea. Although some probiotics have been shown to be beneficial in the treatment of acute diarrhea due to rotavirus, their use in the treatment of diarrhea is yet to be recommended, even in developed countries. The children of developing countries might benefit from zinc supplementation during the diarrheal illness, but its mode of delivery and cost effectiveness are yet to be decided.

Effects of dietary alpha-linolenic acid from blended oils on biochemical indices of coronary heart disease in Indians

PUFA of the n-6 and n-3 series have beneficial effects on key risk factors of coronary heart disease (CHD). Our earlier studies on the intake of FA and on the FA composition of plasma and platelet phospholipids suggested the need to improve the n-3 PUFA nutritional status in the Indian population. The present long-term study was conducted on 80 middle-aged Indian subjects (40 men and 40 women) using the subjects' own home-prepared diets to evaluate the effects of dietary n-3 PUFA on biochemical indices of CHD risk. Substitution of Blend G (equal proportions of groundnut and canola oils) for groundnut oil or substitution of Blend S (equal proportions of sunflower and canola oils) for sunflower oil increased alpha-linolenic acid (ALNA) fourfold and decreased the linoleic acid (LA)/ALNA ratio from 35 to 6 and 65 to 9, respectively. Twelve subjects (six men and six women) who received Blend G were switched back to groundnut oil and were administered 0.3 g daily of long-chain (LC) n-3 PUFA from fish oil. At the end of the trial period for both blends in both sexes, plasma lipid and apolipoprotein levels had not changed, and ADP-induced aggregation had decreased. In plasma and platelet phospholipids, LA as well as LCn-3 PUFA had increased, suggesting competition between LA and ALNA for metabolism into the respective LC-PUFA. Fish oil supplementation increased LCn-3 PUFA in plasma and platelet phospholipids, decreased ADP-induced platelet aggregation, and increased plasma cholesterol. On the basis of the increased LCn-3 PUFA in plasma phospholipids, it was calculated that 0.75% energy (en%) (2.2 g) ALNA (from vegetable oils) may be required to increase LCn-3 PUFA to about the same extent as 0.1 en% (0.3 g) LCn-3 PUFA (from fish oils). Since both n-6 and n-3 PUFA play a critical role in fetal growth and development and in the programming of diet-related chronic diseases in adults, an improvement in the n-3 PUFA nutritional status in cereal-based diets through long-term use of cooking oils containing 25-40% LA and 4% ALNA may contribute to the prevention of CHD in Indians.