Children consuming fish at least once a week have a better intelligence quotient (IQ) and also sleep better than those who don’t consume it at all or consume it less frequently, a new study at the University of Pennsylvania has said.

While the relationship between omega-3s – fatty acids present in fish – with improved intelligence has found its place in earlier reports, this is the first time that a proper link has been ascertained.

The study was published in Scientific Reports, an online open access scientific journal published by the Nature Group. It links sleep as a pathway linking sleep to intelligence.

Each of 541 children in China between the ages of 9 and 11 who were part of the study completed a questionanaire that logged their consumption of fish over the last month and then took a Chinese IQ test called the Wechsler Intelligence Scale for Children-Revised that tests their verbal and non-verbal skills. Parents of these children answered a standardised Children Sleep Habits Questionnaire, with inputs on daytime sleep and waking up at night.

Children who reported weekly consumption of fish scored 4.8 points higher on the IQ tests than those who reported their consumption as seldom or never. Those whose meals included fish at times scored 3.3 points higher. Along with this, an increase in fish consumption showed a fewer disturbances in sleep.