Randomized placebo-controlled trial of guava juice as a source of ascorbic acid to reduce iron deficiency in Tarahumara indigenous schoolchildren of northern Mexico.

OBJECTIVE

Assess the efficacy of a 10-week consumption of guava juice on the iron status of children with mild iron deficiency anemia.

METHODS

Ninety-five boarding school children aged 6-9 years identified as anemic were randomly allocated to receive 300 mL of natural guava juice containing ∼200 mg of ascorbic acid (AA) or placebo (guava-flavored juice free of AA) with the main meal (5 d/wk). Information about dietary intake was collected at weeks 3, 5, and 7 at school and household levels. Changes in hemoglobin (Hb) and plasma ferritin (PF) among the subsample iron deficient at baseline (n = 33) were the main outcomes.

RESULTS

Iron and phytic acid intakes at school and at home did not differ between groups. Baseline Hb and PF were 11.9 ± 0.5 g/dL and 8.2 ± 3.6 ng/mL for the guava, and 11.4 ± 1.1 g/dL and 7.4 ± 4.6 ng/mL for the placebo group (Hb: p = 0.08; PF: p = 0.31); at week 10 of the study, corresponding values were 13.1 ± 0.9 g/dL and 17.9 ± 10.3 ng/mL (n = 16), and 12.3 ± 1.3 g/dL and 15.4 ± 5.8 ng/mL (n = 12) (Hb: p = 0.05; PF: p = 0.21). With analysis of variance (ANOVA) for repeated measures, the guava group had 0.64 g/dL higher Hb (CI(95), 0.18-1.11; p = 0.01) and 2.47 ng/mL higher PF (CI(95), -1.04 to 5.98; p = 0.12) compared with the placebo group.

CONCLUSION

Guava juice providing 200 mg AA at one meal on each school day had a marginal effect on Hb and PF concentrations in children consuming high-phytate diets fortified with iron.