The new research was published recently in the journal Neurology. It was the work of researchers from California, Massachusetts, South Dakota and Texas.
The research uses a data set derived from the Framingham Offspring Study, which was conducted 10 years ago. This research follows on the series of Framingham longitudinal research studies.
Omega-3s help, but how?
The authors sought to delineate a mechanism of action for the way in which omega-3s protect human brains. Higher levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in the blood already have been related to a reduced risk for dementia, but the underlying reasons for this correlation have been unclear.
The researchers chose to look the relationship between red blood cell (RBC) fatty acid levels (i.e., the Omega-3 Index), alongside brain imaging data, including MRI results and cognitive markers of dementia risk, such as subjects who have the APOE-e4 genotype. The study included data from 2,183 subjects with an average age of 46, split about evening between men and women. The subjects were free of dementia and none had suffered strokes. About 22% of the subjects carrier the APOE-e4 genotype.
The authors found that a higher overall Omega-3 Index, which measures EPA and DHA levels in red blood cell tissue, was associated with larger hippo campuses in those subjects. Those subjects also performed better on abstract reasoning tests.
In the past, dietary interventions with omega-3s have shown inconsistent results when looking at lessening the risk of developing dementia or delaying the onset of this devastating condition.
Earlier is better
The authors of the present study speculated that many of these studies may have begun the intervention too late in a subject’s life, when negative changes in the structure of the brain, such as shrinking of brain tissue and changes in the organ’s vasculature, have already taken hold.
“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,” the 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,” said William S. Harris, PhD, FACN, President of the Fatty Acid Research Institute (FARI), and one of the study authors.
“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,” Dr. Harris said.
Association of Red Blood Cell Omega-3 Fatty Acids with MRI Markers and Cognitive Function in Midlife – The Framingham Heart Study
Authors: Saltizabel CL, et al.