Nutritionist’s Perspective on Behavioral Assessment
While nutrition is accepted as key to optimal human development, nutrition intervention trials in populations and RCTs of specific nutrients that have measured developmental outcomes have occurred only recently. The earliest study of this type was a protein intervention during pregnancy and early childhood conducted in Guatemala between 1969 and 1977. About the same time, advances in neonatal medicine allowed the survival of preterm infants. Eventually, this led to randomized clinical studies of nutrition and cognitive development in preterm infants, because it was recognized that their nutritional requirements were difficult to achieve and were associated with compromised neurobehavioral development.
Methods used in nutrition, clinical trial and population research, and behavioral studies have advanced since the 70s; however, the key principles for successful interdisciplinary research on nutrition and cognition have not changed. The importance of having experts from both disciplines working together, preferably as co-equals, cannot be overemphasized. This is particularly important to the nutritionist studying cognitive development, because nutritionists do not routinely study the timing of brain development or the cognitive assessments appropriate during specific periods of development.
Another principle to be explored is the need for prior evidence a nutritional deficiency exists in a population or group as well as plausible evidence the deficiency may compromise cognitive function or cognitive development. Ideally, evidence of a nutrient deficiency in the population should be identified by a biomarker that also responds to supplementation of the nutrient.
Because most populations include some proportion of individuals who are not deficient in the nutrient of interest, the nutrient status of all individuals included in trials should be measured before and after the intervention. These principles and others that contribute to the value of the cognitive information collected will be explored in more detail.