Kids who eat fish at least once a week sleep better and have IQ scores that are 4 points higher, on average, than those who eat fish less frequently or not at all, a new study shows.
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 researchers hadn’t connected all three before. The findings reveal sleep as a possible mediating pathway, the potential missing link between fish and intelligence. “This area of research is not welldeveloped. It’s emerging,” says Jianghong Liu, associate professor of nursing and public health at the University of Pennsylvania and lead author of the study.
“Here we look at omega-3s coming from our food instead of from supplements.” For the work, a cohort of 541 9- to 11-year-olds in China, 54 percent boys and 46 percent girls, completed a questionnaire about how often they ate fish in the past month, with options ranging from “never” to “at least once per week.” Children also took the Chinese version of an IQ test called the Wechsler Intelligence Scale for Children-Revised, which examines verbal and non-verbal skills such as vocabulary and coding.
Their parents then answered questions about sleep quality using the standardised Children Sleep Habits Questionnaire, which included topics such as sleep duration and frequency of night waking or daytime sleepiness. Finally, the researchers controlled for demographic information, including parental education, occupation, and marital status, as well as the number of children in the home. The findings show 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. Further, increased fish consumption was linked to fewer disturbances of sleep, which the researchers say indicates better overall sleep quality.