New findings from the University of
Pennsylvania suggest children who eat fish at least once a week sleep better
and have IQ scores that are 4 points higher, on average, than those who consume
fish less frequently or not at all.
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. This work, conducted by Jianghong Liu, Jennifer Pinto-Martin
and Alexandra Hanlon of the School of Nursing and Penn Integrates Knowledge
Professor Adrian Raine, reveals sleep as a possible mediating pathway, the
potential missing link between fish and intelligence.
For the work, a cohort of 541 9- to
11-year-olds in China, 54 per cent boys and 46 per cent girls, 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.
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.
Analysing these data points, the
Penn 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 the researchers say indicates better overall sleep quality.
Pinto-Martin, who is executive
director of Penn's Center for Public Health Initiatives, says, 'Children should
be introduced to it early on.'
'Introducing the taste early makes
it more palatable,' Pinto-Martin said. Children are sensitive to smell. If they're
not used to it, they may shy away from it.'
For the moment, the researchers
recommend incrementally incorporating additional fish into a diet; consumption
even once a week moves a family into the 'high' fish-eating group as defined in
'Doing that could be a lot easier
than nudging children about going to bed,' Raine said. 'If the fish improves
sleep, great. If it also improves cognitive performance -- like we've seen here
-- even better. It's a double hit.'