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United States Department of Agriculture

Agricultural Research Service

Research Project: ABSORPTION AND METABOLISM OF ESSENTIAL MINERAL NUTRIENTS IN CHILDREN

Location: Children's Nutrition Research Center

Title: Inclusion of guava enhances non-heme iron bioavailability but not fractional zinc absorption from a rice-based meal in adolescents

Authors
item Nair, Krishnapillai -
item Brahmam, Ginnela -
item Radhika, Madhari -
item Dripta, Roy -
item Ravinder, Punjal -
item Balakrishna, Nagalla -
item Chen, Zhensheng -
item Hawthorne, Keli -
item Abrams, Steven -

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 6, 2013
Publication Date: June 1, 2013
Citation: Nair, K.M., Brahmam, G.N., Radhika, M.S., Dripta, R.C., Ravinder, P., Balakrishna, N., Chen, Z., Hawthorne, K.M., Abrams, S.A. 2013. Inclusion of guava enhances non-heme iron bioavailability but not fractional zinc absorption from a rice-based meal in adolescents. Journal of Nutrition. 143(6):852-858.

Interpretive Summary: Assessing how much iron and zinc is absorbed by the body is essential for recommending diets that meet the increased growth-related demand for these nutrients. We studied the absorption of iron and zinc from a rice-based meal in 16 adolescent boys and girls, 13–15 years of age, from schools in India. Participants were given a standardized rice meal and the same meal with 100 g of guava fruit with a stable isotope of iron on two consecutive days. Zinc absorption was assessed by using stable isotope of zinc. The absorption of iron from the modified meal, compared with regular meal, was significantly greater in both girls and boys. Zinc absorption was similar between the regular and modified meals in both sexes. We conclude that simultaneous ingestion of guava fruit with a habitual rice-based meal enhances iron absorption in adolescents.

Technical Abstract: Assessing the bioavailability of non-heme iron and zinc is essential for recommending diets that meet the increased growth-related demand for these nutrients. We studied the bioavailability of iron and zinc from a rice-based meal in 16 adolescent boys and girls, 13–15 y of age, from 2 government-run residential schools. Participants were given a standardized rice meal (regular) and the same meal with 100 g of guava fruit (modified) with 57Fe on 2 consecutive days. A single oral dose of 58Fe in orange juice was given at a separate time as a reference dose. Zinc absorption was assessed by using 70Zn, administered intravenously, and 67Zn given orally with meals. The mean hemoglobin concentration was similar in girls (129 +/- 7.8 g/L) and boys (126 +/- 7.1 g/L). There were no sex differences in the indicators of iron and zinc status except for a higher hepcidin concentration in boys (P < 0.05). The regular and modified meals were similar in total iron (10–13 mg/meal) and zinc (2.7 mg/meal) content. The molar ratio of iron to phytic acid was >1:1, but the modified diet had 20 times greater ascorbic acid content. The absorption of 57Fe from the modified meal, compared with regular meal, was significantly (P < 0.05) greater in both girls (23.9 +/- 11.2 vs. 9.7 +/- 6.5%) and boys (19.2 +/- 8.4 vs. 8.6 +/- 4.1%). Fractional zinc absorption was similar between the regular and modified meals in both sexes. Hepcidin was found to be a significant predictor of iron absorption (standardized beta = 20.63, P = 0.001, R2 = 0.40) from the reference dose. There was no significant effect of sex on iron and zinc bioavailability from meals. We conclude that simultaneous ingestion of guava fruit with a habitual rice-based meal enhances iron bioavailability in adolescents.

Last Modified: 9/21/2014
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