Food for Thought for Kids
By Donald R. Davis, Ph.D.
Can the typical diets of American children impair their learning, IQ, and behavior at school and home? The idea seems unlikely to many parents and educators who assume that brain function is divorced from nutrition and that American diets are rarely deficient. Such assumptions are easily questioned; but still, “unlikely”new ideas like this need evidence. Here I will summarize nearly 20 years of research that suggests it is time for parents, educators, and public officials to reexamine old ideas and seek new ways to help children.
… our brains “consume about 20 percent of the oxygen and fuel that our whole body uses at rest.”
First, about those assumptions. Our brains are metabolic “hot spots.” With only two percent of our body weight, they consume about 20 percent of the oxygen and fuel that our whole body uses at rest. We know that the biological “burning” of oxygen and fuel requires every essential vitamin, mineral, amino acid, and fatty acid. As for the quality of American diets, nutrition surveys since the 1950s have found that many children get less than recommended amounts of nutrients. Overt deficiencies are rare, but learning, IQ, and behavior are on a growing list of “early warning signs” that occur without easily recognized deficiencies. Further’ skipped meals may make children inattentive, initable, and unable to learn, even if overall nutrient intake is fine.
Much of the evidence for nutrition’s role in learning, IQ, and behavior comes from Stephen J. Schoenthaler’s group at California State University, Stanislaus. Since about 1980, he has published over a dozen studies done in schools and facilities for delinquent youths. Early studies with delinquents replaced sugary foods and white flour with fruit and whole grains. He consistently found about a 40% reduction in behavior problems. A study in 803 New York City public schools made similar changes in school meals for 1.1 million children in grades 1 through 8. Following these food changes-which included bans of “nonessential” additives, colors, and flavors-standardized achievement test scores improved 16 percentiles. Before the diet changes, schools with the most students receiving school meals had the worst academic performance. Afterwards, this statistic reversed; the more school meals served, the better the performance.
These early studies are only suggestive, because there were no untreated comparison subjects, and non-diet factors may have been important diet change studies are difficult or impossible to do without the subjects’ awareness, so Schoenthaler carried out later studies in which he gave nutritional supplements to some subjects and lookalike placebos to others. The supplements contained roughly recommended daily amounts of 13 vitamins and 10 minerals. They don’t fully substitute for fruits and whole grains, but positive results with supplements are more convincing and easier to interpret than with dietary changes.
In an Oklahoma study of 26 incarcerated delinquents, behavior improved in supplemented subjects compared to placebo subjects, and their “non-verbal” IQ improved significantly (average 5 points). In a 3-month study of 615 eighth and tenth graders in four California schools. the supplemented subjects showed modest but reliable gains in non-verbal IQ (average 3.6 points) and in a standardized achievement test. Schoenthaler concludes that at least part of the benefit found in the diet studies in New York City schools and elsewhere was due to improved intake of vitamins and minerals. He suggests that sugar harms mostly by replacing fruits and other nutritious foods.
Another group, headed by David Benton at University College in Wales, has reported three placebo-controlled studies of nutritional supplements and IQ in school children. In each case nonverbal IQ increased reliably, relative to the placebo (average 5 to 10 points) after 6 weeks to 8 months. Diet analyses in the same subjects suggested that mainly the poorer-fed children benefited. In one study that estimated sugar intakes, IQ increases were largest in those who ate the most sugar. Benton urges further study of the relationship of IQ and nutrition and suggests that IQ is unlikely to be the only brain function affected.
Together, these and other studies seem worthy of the attention of parents, educators, and public officials. The indicated diet changes are hardly new (decrease added sugars and white flour, increase fruits and whole grains). They have been recommended for decades. All pet manufacturers and animal farmers follow similar practices.
What can parents do?
First, they can set good examples at home, replacing most sweet pastries and candies with fruits; replacing sodas and sugared “drinks” with 100% fruit juices and milk; replacing high-sugar cereals with low-sugar, whole-grain cereals sweetened with generous amounts of banana, apple, or fresh or frozen strawberries and blueberries; and using whole grain breads.
They can teach their children that when mother nature gave us a sweet tooth she surely did not have in mind that we get 20 to 25% of our national calories from refined, nutrientless sugar or fructose in sodas and other sweets. (Remarkably, fruits supply only about 4% of U.S. calories.)
Parents can band together and protest where schools allow or consider allowing vending machines with candy , sodas, or other sugared confections, some of which may be misrepresented as “natural” or healthful. They can work with school food services to introduce improvements similar to those used by Schoenthaler in New York City public schools and in corrections institutions.
They can choose to make meal preparation and eating, including breakfast, a time of relaxed family sharing. If we skip meals or don’t take time to prepare and eat good meals, we and our children will likely pay a price in how we feel and function at work and school, and in our nutrition, as we later feel compelled to grab whatever is available in vending machines and fast food outlets.
I hope the growing knowledge about school achievement, IQ, and behavior will give parents new food for thought. Let’s not be careless about the 20% of our metabolism that we are beginning to realize is just as important as, and helps improve, everything else we and our children are likely to do today.