Study links fishy diet to higher IQ due to better sleep

Fish on Fridays, and maybe on Wednesdays and Mondays too.

Fish on Fridays, and maybe on Wednesdays and Mondays too

(Credit: iStock/Getty Images)

Unlike the rest of my clan, I was not a fan of fish of growing up. But like many Catholic families, every Friday, fish was dutifully served. My mother's motivational offering of "eat up - fish is brain food" did little to ignite my enthusiasm. My nose and gag reflex held my focus at the time. Still, I ate the stuff.

As usual, it turns out mom was right. A fearlessly fishy diet has long been shown to better the brain. Though Health Canada would have you note that supping on smaller fish is advised due to mercury level concerns, fish consumption has been linked to a reduction of brain shrinkage and improved cognitive function in seniors. It's also been linked to benefits in other realms of brain health like depression and mood management. There's even evidence to suggest that our ancient ancestors owe the relatively rapid development of their frontal lobes to frequently feasting on fish about 2 million years ago. Newer research now places some of the much touted brain boosts on one welcome side-effect of eating fish just once a week: improved sleep.

Findings from the University of Pennsylvania showed that kids who ate fish once a week slept better and, subsequently, had higher IQ scores than children who dined on fish less often (or never let a mackerel touch their lips). In fact, IQ ratings for the fish group was typically about 4 points higher than those of their fish averse peers. While there's no shortage of evidence to support the benefits of fatty acids like Omega-3s found in fish (one study showed that pregnant women who dined on fish gave birth to brainier babies), this new study adds a wrinkle to existing data. Researchers are clear that "this is the first study to indicate that frequent fish consumption may help reduce sleep problems (better sleep quality), which may in turn benefit long-term cognitive functioning in children." Improved sleep could be the thing that links fish consumption to intelligence or rather, as researchers suspect, that "sleep quality mediates the fish-IQ relationship."  

Relying first on data from self-reported dietary and sleep habits of 541 Chinese boys and girls between the ages of 9 and 11, researchers then administered a well-established IQ test (the Wechsler Intelligence Scale for Children-Revised). Note here that parents, too, were grilled for info on dietary habits and sleep patterns in the home before the test was taken.

Not only was a higher dietary presence of fish associated with more restful sleep free of disturbances, but the kids who could report eating fish weekly scored 4.8 points higher on the Wechsler test than kids who "seldom" or "never" sat down to a meal of fish. What's more, even kids whose diet only included fish occasionally still saw a 3.3 point jump in IQ. If that doesn't blow your fish-loving brain, consider that an average score for the Wechsler test is "100, and any score from 90 to 109 is considered to be in the average intelligence range," as per the Wechsler page.  They also confirm that anything between 110 to 119 is deemed "high average". So, a five-point differential due to a serving of broiled salmon once a week is considerable.

Sleep quality cannot be overlooked here, say researchers.  Dr. Adrian Raine, professor at Penn's Perelman School of Medicine, who co-wrote the study says, "lack of sleep is associated with antisocial behavior; poor cognition is associated with antisocial behavior." The correlation between cognition, sleep and fish for Raine is easily made. In a previous study involving kids, Raine confirms "we found that omega-3 supplements reduce antisocial behavior, so it's not too surprising that fish is behind this."

Dr. Jennifer Pinto-Martin, executive director of Penn's Center for Public Health Initiatives certainly sees the value of adding a little fish to the human diet from a very young age and this new research supports that. "It adds to the growing body of evidence showing that fish consumption has really positive health benefits and should be something more heavily advertised and promoted," says Pinto-Martin who also co-authored the study. "Children should be introduced to it early on." It could be a bit of an uphill battle in some homes (apologies to my parents here for any decidedly bratty anti-fish sentiment I sent their way as a kid). "Introducing the taste early makes it more palatable," Pinto-Martin told media. "It really has to be a concerted effort, especially in a culture where fish is not as commonly served or smelled. Children are sensitive to smell. If they're not used to it, they may shy away from it." So many fish flashbacks are punctuated by my olfactory memory - which is weird because I am now and forever will be madly in love with grilled salmon. Go figure.

Still, Pinto-Martin's recommendation is to begin young as 10 months but no later than age 2 — tiny bones, of course, need to be minded and mined out accordingly. To be sure, researchers suggest folding fish into meal plans incrementally if your family has rarely stopped at the fish counter. Seeing as just one weekly dose puts families from the study in the "high" fish eating category, it may be worth putting up with small, wrinkled noses one day out of seven.  

Marc Beaulieu is a Montreal writer, producer, performer, professional host and mental health advocate whose one true love is weird news.