The new research was published last week in the journal European Child & Adolescent Psychology. It was the work of a group of researchers led by Ariadna Pinar-Martí, PhD, of the Universitat Pompeu Fabra in Barcelona. One of her coauthors, Aleix Sala-Vila, is a member of the Fatty Acid Research Institute (FARI) based in Sioux Falls, SD.
Data taken from cohort of Spanish teenagers
Like many other such recent omega-3s studies, the researchers in this case were using data collected from a cohort assembled as part of a different study. In this case the cohort of 771 healthy adolescents were part of the Walnuts Smart Snack Dietary Intervention Trial, which is a randomized controlled trial aimed at evaluating whether eating four walnuts (or 30 grams) a day for six months improved brain neuropsychological and socio-emotional development compared to a control group that ate no walnuts. The study population was healthy teenagers in the 11 to 16 age group.
The original walnut study sought to recruit teenagers from high schools across the Barcelona metro area in an effort to correct for socioeconomic differences. The teenagers underwent a battery of neuropsychological tests prior to being randomly assigned to one of the groups.
As part of that trial, blood was drawn from a subset of the teenagers. The blood of 332 subjects was analyzed by Sala-Vila using the Omega-3 Index methodology co developed by Dr William S Harris, PhD, who is now the head of FARI.
The researchers used a standard computer test called the Attention Network Test (ANT) to assess attention function performance. The test consists of being presented with a screen with five arrows on it and indicating as fast as possible the direction of the central arrow. The test purports to engage the orienting, alerting and executive attention neural networks.
In particular, they measured the pre-and post-intevnetion difference in the hit reaction time (HRT) and hit reaction time standard error (HRT-SE). These measures captured aspects of attention, conflict response and impulsivity, according to the researchers.
DHA boosts attention performance
The researchers found higher DHA levels, as measured in an Omega-3 Index test, were “associated with better attention functioning, based on scores of shorter latencies of hit reaction time and lower executive conflict response.”
The researchers also looked into ALA levels (the PUFA that is supplied in walnuts), but the signal there was less clear, though they did say that higher ALA levels in the blood appeared to be associated with reduced impulsivity.
“Overall, this reinforces the long-known importance of ensuring an adequate DHA accumulation in periods of life when the brain is developing or evolving, being adolescence of paramount importance,” the researchers added.
Harris, who was not involved with the design or implementation of the study, said the result is interesting and important given the nature of the study cohort.
“What’s novel about this is there is very little data with normal adolescents, even on what their omega-3 levels are, much less about what effect the omega-3s are having. To find this relationship in what are otherwise ‘cognitively normal’ kids is pretty cool,” he said.
GOED: Results need to be put into context
Harry Rice, PhD, chief science officer of the Global Organization of EPA and DHA Omega-3s (GOED), was a bit more restrained in his assessment of the importance of the result.
“While the results suggest that higher dietary DHA intake via fish as reflected by higher red blood cell DHA levels is associated with better attention performance in adolescents, it's important to keep in mind that this was a cross-sectional analysis of data collected for a study that was designed to better understand the role of plant-based omega-3 PUFA intake on consumption on neuropsychological development during adolescence. Thus said, the original study had nothing to do with DHA. That doesn't mean I'm dismissing the present results. I think they are intriguing and provide a reason to conduct future research, but they are far from conclusive, particularly given past mixed results looking at the benefits of DHA (and EPA) on attention,” Rice said.
Source: European Child & Adolescent Psychology
2022 Aug 12. doi: 10.1007/s00787-022-02064-w. Online ahead of print.
Red blood cell omega-3 fatty acids and attention scores in healthy adolescents
Authors: Pinar-Martí A, et al.