Avocado Consumption, Nutrients in Human Milk, and Infant Cognitive Development

Nutrients do not appear in nature alone with some appearing together more often than not. It is reasonable to posit that nutrients are working together, and thus, the synergies among the nutrients are important to understand. First, choline is integral to brain fatty acids in that phosphatidylcholine (PC) serves an active role in mediating hepatic export of fatty acids to extra-hepatic tissues such as brain: fatty acids are stored in the liver, and PC moves them to the brain. Erythrocyte PC-DHA is integral to our consideration of a potential mechanism behind our results. Enriched in docosahexaenoic acid (DHA), PC comprises the cell membrane and influences membrane fluidity with downstream effects on signal transduction thereby improving speed of processing and recognition memory. Lutein has a very important role also in that it is known to co-localize with DHA specifically resulting in improvements in visual acuity, for example, and in general, it has been shown to protect fatty acids from peroxidation. Indeed, interventions with avocado have shown a significant increase in plasma lutein and a decrease in lipid peroxidation. It is hypothesized that lutein is also having this effect in the brain. As work with single nutrient supplementation does not yield strong cognitive effects, the investigators study the effects of co-occurring nutrients on cognitive development. The proposed study is designed to achieve an overall objective of establishing a whole food, avocado, as a viable study material in the pursuit of optimization of human milk with nutrients that support brain development. The long-term goal is to establish guidelines for maternal nutrition during gestation and lactation that include key nutrients for fetal and infant brain development, and the overall impact of this research program will be to set children on a trajectory for school readiness. The central hypothesis is that maternal avocado consumption will provide nutrients through human milk to support the development and function of neural substrates that support cognition. Specifically, choline, lutein, and fatty acids will work synergistically to improve brain function.

Mothers will be randomized to avocado or no avocado (due to lack of an appropriate control food). Participants will come to the lab 3 times across 6 months (enrollment/3months, 4.5 months, and 6 months). Milk sample will be provided every two weeks and will be picked up from the participants. At pickup, the avocado group will also be provided a new supply of avocados. Diet data will be collected at each visit/pickup (every two weeks). The infant will complete a recognition memory test using electrophysiology at 6 months as well as the Bayley Scales of Infant Development at 4.5 months. The mother will complete a temperament questionnaire at 3 and 6 months. Saliva samples will also be collected.