According to a study published in the journal Scientific Reports, children who eat fish at least once a week sleep better and have IQ scores that are four points higher than those who consume fish less frequently or not at all.
According to Liu et al, frequent fish consumption may help reduce sleep problems (better sleep quality), which may in turn benefit long-term cognitive functioning in children. Image credit: Takedahrs.
Previous studies showed a relationship between omega-3s, the fatty acids in many types of fish, and improved intelligence, as well as omega-3s and better sleep. But they’ve never all been connected before.
The new study, led Dr. Jianghong Liu from the University of Pennsylvania Schools of Nursing and Medicine, reveals sleep as a possible mediating pathway, the potential missing link between fish and intelligence.
“This area of research is not well-developed. It’s emerging. Here we look at omega-3s coming from our food instead of from supplements,” Dr. Liu said.
The study involved 541 (54% boys and 46% girls) Chinese schoolchildren. Fish consumption and sleep quality were assessed at age 9-11 years, while IQ was assessed at age 12.
“The schoolchildren completed a questionnaire about how often they consumed fish in the past month, with options ranging from ‘never’ to ‘at least once per week.’ They also took the Chinese version of an IQ test called the Wechsler Intelligence Scale for Children-Revised,” the authors said.
“Their parents then answered questions about sleep quality using the standardized Children Sleep Habits Questionnaire, which included topics such as sleep duration and frequency of night waking or daytime sleepiness.”
The team found that children who reported eating fish weekly scored 4.8 points higher on the IQ exams than those who said they ‘seldom’ or ‘never’ consumed fish. Those whose meals sometimes included fish scored 3.3 points higher.
In addition, increased fish consumption was associated with fewer disturbances of sleep, which indicates better overall sleep quality.
“Lack of sleep is associated with antisocial behavior; poor cognition is associated with antisocial behavior,” said co-author Professor Adrian Raine, from the University of Pennsylvania School of Arts and Sciences.
“We have found that omega-3 supplements reduce antisocial behavior, so it’s not too surprising that fish is behind this.”
“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. Children should be introduced to it early on,” said Dr. Jennifer Pinto-Martin, from the University of Pennsylvania Schools of Nursing and Medicine.
“That could be as young as 10 months, as long as the fish has no bones and has been finely chopped, but should start by around age 2.”
“Introducing the taste early makes it more palatable. 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.”
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Jianghong Liu et al. 2017. The mediating role of sleep in the fish consumption – cognitive functioning relationship: a cohort study. Scientific Reports 7, article number: 17961; doi: 10.1038/s41598-017-17520-w
