Monounsaturated fatty acids linked to benefits for brain network organization

29 Oct 2018 --- A new study by University of Illinois researchers has found that monounsaturated fatty acids – a class of nutrients found in olive oils, nuts and avocados – are linked to general intelligence, and that this relationship is driven by the correlation between MUFAs and the organization of the brain's attention network. Although nutrition has been linked to cognitive performance, the mechanism behind the connection has remained elusive.

Published in the journal NeuroImage, the study of 99 healthy older adults, recruited through Carle Foundation Hospital in Urbana, compared patterns of fatty acid nutrients found in blood samples, functional MRI data that measured the efficiency of brain networks and the results of a general intelligence test. 

“Our goal is to understand how nutrition might be used to support cognitive performance and to study the ways in which nutrition may influence the functional organization of the human brain,” says study leader Aron Barbey, a Professor of Psychology. 

This understanding is important for the development of nutritional interventions that are effective at enhancing cognitive performance, Barbey adds.

“In this study, we examined the relationship between groups of fatty acids and brain networks that underlie general intelligence. In doing so, we sought to understand if brain network organization mediated the relationship between fatty acids and general intelligence,” says Marta Zamroziewicz, a Ph.D. graduate of the neuroscience program at Illinois and lead author of the study.

Studies suggesting cognitive benefits of the Mediterranean diet, which is rich in MUFAs, inspired the researchers to focus on this group of fatty acids. They examined nutrients in participants' blood and found that the fatty acids clustered into two patterns: saturated fatty acids and MUFAs.

“Historically, the approach has been to focus on individual nutrients. But we know that dietary intake doesn't depend on any one specific nutrient; rather, it reflects broader dietary patterns,” says Barbey, who also is affiliated with the Beckman Institute for Advanced Science and Technology at Illinois.

The researchers found that general intelligence was associated with the brain's dorsal attention network, which plays a central role in attention-demanding tasks and everyday problem solving. In particular, the researchers found that general intelligence was associated with how efficiently the dorsal attention network is functionally organized used a measure called small-world propensity, which describes how well the neural network is connected within locally clustered regions as well as across globally integrated systems.

In turn, they found that those with higher levels of MUFAs in their blood had greater small-world propensity in their dorsal attention network. Taken together with an observed correlation between higher levels of MUFAs and greater general intelligence, these findings suggest a pathway by which MUFAs affect cognition.

“Our findings provide novel evidence that MUFAs are related to a very specific brain network, the dorsal attentional network, and how optimal this network is functionally organized,” Barbey says. “Our results suggest that if we want to understand the relationship between MUFAs and general intelligence, we need to take the dorsal attention network into account. It's part of the underlying mechanism that contributes to their relationship.”

The researchers hope these findings will guide further research into how nutrition affects cognition and intelligence. In particular, the next step is to run an interventional study over time to see whether long-term MUFA intake influences brain network organization and intelligence.