“DHA is still the king of the ingredients in cognitive health,” said Mark Strobel, Industry Analyst – Consumer Health, Euromonitor International during the recent NutraIngredients-USA Cognitive Health Forum
. “Since it’s already widely recognized and highly used it’s had less of a barrier to cross from the cardiovascular segment into the neuro-health,” he added.
“Of all the substances reported to affect cognition, the long-chain omega-3s, EPA and DHA, are associated with the largest (and growing) body of scientific evidence,” said Dr Harry Rice:
“Cognition is a general term and the evidence of a benefit is stronger in some areas than in other areas.”
Attention deficit [Hyperactivity] Disorder (AD[H]D)
Dr Rice noted that there is no shortage of reports of relative n-3 LCPUFA deficiencies in children with ADHD. “To date, results from randomized clinical trials have been equivocal,” he said, “but there has been at least one important learning worth noting. It appears that the greatest benefit may be demonstrated in those with low n-3 LCPUFA levels.”
While no particular endpoint consistently stands out as changing as a result of circulating n-3 LCPUFA levels or supplementation, Dr Rice said that he believes this will change if the research is focused on the population with the greatest potential of demonstrating a benefit – those with low n-3 LCPUFA levels.
Cognitive Decline and Alzheimer’s Disease (AD)
“While results from clinical trials do not provide much support for a therapeutic role for omega-3s in the treatment of cognitive decline or AD, the prevention or risk reduction is another story and that’s really where future research should focus,” said Dr Rice.
“With respect to future research, careful attention needs to be given to subject recruitment. Here’s why. Apolipoprotein-ε4 (APOE-ε4) is a major genetic risk factor for cognitive decline and AD and research has demonstrated that APOE-ε4 carriers have an increased risk of developing the condition/disease. These are the individuals you want in your studies.”
Again, there is no consistent endpoint in this area, he said, but there could be a trend towards looking at telomere length in research on cognitive decline and AD.
“An over-simplified explanation of a telomere is that it is the protective end on a chromosome (piece of DNA with genes). Some scientists liken a telomere to the plastic coating on a shoelace,” he explained. “Given that telomere length may provide an early marker of age-related neurodegeneration, the following research results are relevant to the study of n-3 LCPUFAs:
- Baseline blood levels of n-3 LCPUFAs is inversely related to the rate of telomere shortening over 5 years.
- Average telomere length increased with n-3 LCPUFA supplementation.
- Significant telomere attrition over two years has been demonstrated in APOE-ε4 carriers. Herein lies the reason why future research on cognitive decline and AD should consider telomere length an endpoint of interest.”