Children who eat fish at least once a week sleep better and have higher IQ scores than those who consume fish less frequently or not at all, according to new research by the University of Pennsylvania.
Previous studies have shown a relationship between omega-3s, the fatty acids in many types of fish, and improved intelligence, as well as better sleep. But this is the first time they have all been connected.
The study, which has been published in the journal Scientific Reports, reveals sleep as a possible mediating pathway between fish and intelligence.
The study’s lead author, Jianghong Liu, said: ‘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.’
During the study of 541 9 to 11-year-olds in China, (54 per cent boys and 46 per cent girls) participants 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, 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 and number of children in the home.
The researchers 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 the researchers say indicates better overall sleep quality.
The researchers now want to establish, through randomised controlled trials, that eating fish can lead to better sleep, better school performance and other real-life, practical outcomes.