Power Unseen: How Microbes Rule the World

gitudinal study. By ages 11-24, study subjects from the intervention villages scored significantly higher on tests of reading, numeracy, vocabulary, and knowledge than did children from the control villages, and they had faster reaction times in processing information. The impact of nutritional supplementation, however, was greater on intelligence and achievement than on reaction time. The nutritional supplements appeared to provide the greatest benefit to those children in the lowest SES groups, and those who went farthest in school. Although some beneficial effects were still found when supplementation was begun after two years of age, they were less impressive than when supplementation was started prenatally or during the first two years of life. One of the more interesting aspects of the report was the fact that the supplementation improved the growth of children, which in turn influenced the way parents and others treated the children. Children who were larger for a given chronological age were allowed more autonomy and independence, which probably increased their learning, whereas smaller children were treated as though they were younger than their chronological age. Second, the children receiving supplementation were more physically active and did more exploring of their environment, which also may have had a positive effect on their learning. One of the most helpful aspects of the monograph was two commentaries at the end by two leading investigators in the field, Theodore Wachs and Nevin Scrimshaw, and a response by the authors. These commentaries served to deepen the reader's understanding of the issues involved in the complex and understudied field of the role of nutrition in cognitive development. This is an important study for world health, and it is interesting and reads well. The monograph is strongly recommended to persons interested in nutrition and/or cognitive development.