Inclusion of Guava Enhances Non-Heme Iron Bioavailability but Not Fractional Zinc Absorption from a Rice-Based Meal in Adolescents

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 (57)Fe on 2 consecutive days. A single oral dose of (58)Fe in orange juice was given at a separate time as a reference dose. Zinc absorption was assessed by using (70)Zn, administered intravenously, and (67)Zn 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 (57)Fe 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 β = -0.63, P = 0.001, R(2) = 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.

Iron and Zinc Nutrition in the Economically-Developed World: A Review

“…Ascorbic acid has consistently been shown to enhance iron absorption when provided in single-meal studies as food sources [9,76,105,106] or in fortificant form [79,105]. Importantly, the improvement in iron absorption seems to vary depending on the composition of the meal, with 50 mg ascorbic acid (equivalent to approximately 100 g of fresh orange) increasing absorption by 61% from a hamburger meal and 164% from a pizza meal [105].…”

“…Single-meal studies measuring zinc absorption with ascorbic acid naturally present in a food source [9] or added as a fortificant [111] found no enhancing or inhibiting effects.…”

“…In human nutrition, zinc and iron are frequently assessed together [3,4,5,6,7,8,9] as these minerals share common dietary sources, the absorption of both nutrients from food is believed to be enhanced and inhibited by similar compounds [4,5,7,9], and consequently, deficiency of both nutrients is thought to occur simultaneously. This review aims to discuss iron and zinc in terms of dietary sources, bioavailability and dietary interactions drawing on literature from human studies.…”

FORTIFIKASI GUAVA (Psidium guajava L.) JELLY DRINK DENGAN ZAT BESI ORGANIK DARI KEDELAI (Glycine max L.) DAN KACANG HIJAU (Vigna radiate L.)

“…Dalam penelitiannya, Nair et al (2013) mengungkapkan bahwa dengan mengonsumsi 100 g buah jambu biji segar, mampu meningkatkan penyerapan zat besi …”

A food synergy approach in a national program to improve the micronutrient status of preschoolers: a randomized control trial protocol

“…Numerous studies of food synergy have researched the effects of vitamin C on improving nonheme iron bioavailability. Vitamin C from food, particularly fruits, has been shown to improve iron absorption two‐ to threefold from meals . Vitamin C reduces dietary ferric iron (Fe 3+ ) to ferrous (Fe 2+ ), which enhances absorption of nonheme iron .…”