Data from the Kuopio Ischaemic Heart Disease Risk Factor Study indicated that higher serum omega-3 levels were associated with significantly better performance on the Trail Making Test and the Verbal Fluency Test, which assess specific cognitive domains such as the ability to shift from alternating concepts or to produce words in a limited letter category.
On the other hand, no benefits were observed in the Selective Reminding Test, the Visual Reproduction Test and the Mini Mental State Exam, wrote the researchers in the European Journal of Clinical Nutrition .
The researchers also noted that there were no links between exposure to mercury (the omega-3 in the diet of this study population came mainly from fish) and cognitive performance.
“Several mechanisms may explain the benefits of the long-chain omega-3 PUFAs on cognitive performance. These fatty acids, especially DHA, increase brain phospholipid levels, may increase neuronal survival and have beneficial effects on neurite outgrowth and synaptogenesis that are involved in nervous system development and repair,” explained the researchers.
“DHA also stimulates neurogenesis in adult brain. Furthermore, long-chain omega-3 PUFAs have anti-inflammatory and anti-oxidative properties, both present in aging and in chronic diseases, and their presence in cell membranes of the brain is essential in order to have an effective neurotransmission”
The Trail Making Test measures perceptual motor speed, visual searching and sequencing, and the ability to make alternating conceptual shifts.
The Verbal Fluency Test assesses language performance and the ability to spontaneously produce words under the restrictions of a limited letter category (in other words, participants were asked to list as many words as possible beginning with P, A or S in one minute).
Researchers from the University of Naples Federico II and the University of Eastern Finland analysed data from 768 participants of the Kuopio Ischaemic Heart Disease Risk Factor Study. This age range of the study population was 53-73 years old.
They found that omega-3 levels were significantly associated with improved cognitive function scores on two of the five tests administered. Specifically, the participants with the highest average levels of EPA+DHA+DPA completed the Trail Making Test 7.1 seconds faster than people with the lowest average omega-3 levels. For the Verbal Fluency Test, participants with the highest average omega-3 levels could list three words more per minute than people with the lowest average levels.
“Higher serum long-chain omega-3 PUFA concentrations were associated with better performance on neuropsychological tests of frontal lobe functioning in older men and women,” they concluded.
Source: European Journal of Clinical Nutrition
Published online ahead of print, doi:10.1038/ejcn.2016.59
“Association between serum long-chain omega-3 polyunsaturated fatty acids and cognitive performance in elderly men and women: The Kuopio Ischaemic Heart Disease Risk Factor Study”
Authors: T A D'Ascoli, J Mursu, S Voutilainen, J Kauhanen, T-P Tuomainen and J K Virtanen