Role of polyunsaturated fatty acids in human brain structure and function across the lifespan: An update on neuroimaging findings

There is a substantial body of evidence from animal studies implicating polyunsaturated fatty acids (PUFA) in neuroinflammatory, neurotrophic, and neuroprotective processes in brain. However, direct evidence for a role of PUFA in human brain structure and function has been lacking. Over the last decade there has been a notable increase in neuroimaging studies that have investigated the impact of PUFA intake and/or blood levels (i.e., biostatus) on brain structure, function, and pathology in human subjects. The majority of these studies specifically evaluated associations between omega-3 PUFA intake and/or biostatus and neuroimaging outcomes using a variety of experimental designs and imaging techniques. This review provides an updated overview of these studies in an effort to identify patterns to guide and inform future research. While the weight of evidence provides general support for a beneficial effect of a habitual diet consisting of higher omega-3 PUFA intake on cortical structure and function in healthy human subjects, additional research is needed to replicate and extend these findings as well as identify response mediators and clarify mechanistic pathways. Controlled intervention trials are also needed to determine whether increasing n-3 PUFA biostatus can prevent or attenuate neuropathological brain changes observed in patients with or at risk for psychiatric disorders and dementia.