Effects of early childhood supplementation with and without stimulation on later development in stunted Jamaican children

It is not known whether nutritional supplementation in early childhood has long-term benefits on stunted children's mental development. We followed up 127 7-8-y old children who had been stunted in early childhood and received supplementation, stimulation, or both. At 9-24 mo of age, the children had been randomly assigned to four treatment groups: nutritional supplementation, stimulation, both treatments, and control. After 2 y, supplementation and stimulation had independent benefits on the children's development and the effects were additive. The group receiving both treatments caught up to a matched group of 32 nonstunted children. Four years after the end of the 2-y intervention 97% of the children were given a battery of cognitive function, school achievement, and fine motor tests. An additional 52 nonstunted children were included. Factor analyses of the test scores produced three factors: general cognitive, perceptual-motor, and memory. One, the perceptual-motor factor, showed a significant benefit from stimulation, and supplementation benefited only those children whose mothers had higher verbal intelligence quotients. However, each intervention group had higher scores than the control subjects on more tests than would be expected by chance (supplemented and both groups on 14 of 15 tests, P = 0.002; stimulated group in 13 of 15 tests, P = 0.01), suggesting a very small global benefit. There was no longer an additive effect of combined treatments at the end of the intervention. The stunted control group had significantly lower scores than the nonstunted children on most tests. Stunted children's heights and head circumferences on enrollment significantly predicted intelligence quotient at follow-up.