A randomized intervention study of the effects of discontinuing coffee intake on growth and morbidity of iron-deficient Guatemalan toddlers.

Coffee is widely consumed by children in Guatemala. To evaluate whether coffee has an adverse effect on growth or morbidity, 160 children 12-24 mo of age who had received coffee for > or = 2 mo and had at least one indicator of iron deficiency were stratified by initial hemoglobin (Hb) (A = anemic vs. NA = "nonanemic", i.e., Hb > or = 105 g/L) and randomly assigned to a control (C = continuation of coffee) or intervention group (S = provided with a substitute consisting of sugar and coloring) for 5 mo. Anemic children were provided iron supplements for 2-3 mo. Hematological and anthropometric measurements were made before and after the intervention, and dietary and morbidity data were collected every 2 wk. A total of 139 children completed the intervention: 45 C-NA, 56 S-NA, 19 C-A and 19 S-A. Compliance with the intervention was good: median coffee intake was 127 mL/d in group C vs. 3 mL/d in group S (P = 0.0001). There were no significant differences between C vs. S groups in food intake before or after the intervention. In the total sample, there was no effect of the intervention on weight or length gain. However, in children initially consuming more than 100 mL/d of coffee (n = 96), length gain was 22% greater in the S vs. the C group (P = 0.07), and weight gain was 46% greater in the S-A vs. the C-A group (P < 0.05; NS in the NA groups). Total illness prevalence (particularly respiratory illness) was significantly lower in the S-NA vs. the C-NA group (P < 0.05), but somewhat higher in the S-A vs. the C-A group (P = 0.09). Morbidity differences did not explain the effect of the intervention on growth. These results indicate a modest increase in growth associated with discontinuation of coffee consumption by toddlers with initial intakes >100 mL/d.