A.B. Mayer1 ([email protected]), M.C. Latham1, J.M. Duxbury2,
N. Hassan3, and E.A. Frongillo1
(1)Division of Nutritional Sciences, Cornell University, Ithaca, NY 14850, USA,
(2)Department of Crop and Soil Sciences, Cornell University, and (3) Institute of Nutrition and Food Science, University of Dhaka, Dhaka 1000, Bangladesh
Common approaches to address micronutrient deficiencies include supplementation, fortification, nutrition education, and dietary diversification. However, there is potential to integrate agriculture and human nutrition using sustainable food systems approaches.
The study was carried out to demonstrate the potential to improve zinc nutrition of children through a series of improvements to agricultural production, rice varieties, processing and cooking of rice, and improvements to water sources.
In a study conducted in Bangladesh in 2000, soil zinc levels were monitored and its uptake in rice was then tracked through human consumption and assimilation. The design was a cross-sectional observational study of zinc content of rice, dietary intake, and nutritional status of children. Samples of raw, parboiled, milled and cooked rice and soil were collected from 4 villages and surrounding areas in different regions. In total, 156 households were enrolled in a diet and nutrition survey. Using household rice samples, dietary zinc intake was individualized for each household. Hair samples were used for zinc nutritional status. Stool samples were collected from children to determine level of intestinal infection. Ethical approval was obtained from Cornell University, USA and University of Dhaka, Bangladesh.
Rice grown in 2 seasons on high-zinc soil (>0.8 ppm available zinc) were 6% and 13% higher in zinc than on soils having <0.8 ppm. The zinc content of local varieties differed by 31% and 41% in 2 seasons. In 2 villages with mills, milling losses were 24% and 39%. Cooking losses averaged 2% or 16% depending on the practice of discarding cooking-water. Rice supplied 64% of children's dietary zinc. Total dietary zinc would increase from 6.4 mg/d to 9.0 mg/d if children aged 5-11years consumed rice from the 'high-zinc' village compared to the 'low-zinc' village. Hair zinc was positively associated with polished rice zinc (r=0.24 p=0.001) suggesting that improvements to the nutrient content of rice could result in nutritional benefit. Children from households using pond water for cooking had higher levels of intestinal infection than those using tubewell water.
Improvement to local systems, including choice of crop varieties, soil and crop management, food processing, and household water sources can enhance children's zinc status through optimizing the zinc content of rice and preventing intestinal infections.