About the research
The researchers note that dietary intake and circulating levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) have been related to a reduced risk for dementia, but the pathways underlying this association remain unclear. Also, no studies look at omega-3s and brain health in middle-aged adults.In this latest study, the researchers looked at the relationship between red blood cell (RBC) fatty acid levels (i.e., the Omega-3 Index), alongside brain imaging data (i.e., MRI) and cognitive markers of dementia risk (i.e., APOE-e4 genotype) in 2,183 subjects with an average age of 46, FARI reports.
The finding: A higher Omega-3 index was associated with larger hippocampal volumes and better abstract reasoning.FARI adds that similar results were obtained for DHA and EPA concentrations individually.
Challenges with past research
FARI reports that, despite beneficial associations observed for brain outcomes in population-based and experimental studies, results from dietary intervention studies using omega-3 EPA and DHA supplementation have been inconsistent. A possible challenge impacting some studies, according to the expert: dietary interventions may be carried out too late for significant improvements in symptomatic participants, as cognitive changes may be well established over the previous 15 to 20 years."Epidemiological and intervention studies suggest omega-3 may be most beneficial to preserve brain health from early midlife, as our study suggests, and just before the onset of moderate cognitive changes," said the authors of the current paper.
William S. Harris, Ph.D., FACN, President of theFatty Acid Research Institute(FARI), and one of the study authors, said, "What’s important about this study is that it replicates what we saw in the Framingham Offspring 10 years ago, in subjects who had an average age of 66. However, this study represents Generation 3, their kids essentially, who had an average of 46. The results of this study show that low red blood cell DHA levels are associated with smaller brain volumes and a ‘vascular’ pattern of cognitive impairment, even in persons free of clinical dementia. This suggests that intervening early and maintaining an optimal Omega-3 Index (8% or higher) could play an important role in staving off cognitive decline, as well as dementia and Alzheimer’s in the long-term."
