School-age children: weekly fish consumption improves sleep and intelligence test scores
Weekly fish consumption can improve sleep quality and promote cognitive abilities in school-age children by improving intelligence test scores.
In fact, according to a new study, kids who consume fish at least once a week sleep better and have an Intelligence Quotient score 4 points higher than those who eat it less frequently. Thus, sleep quality could be one of the connecting factors between omega-3 consumption and cognitive performance.
This is according to a study published by researchers at the University of Pennsylvania (USA) in Nature's journal Scientic Reports.
Omega-3 cognitive function and sleep-wake rhythms: is there a link?
Long-chain omega-3 fats are essential nutrients, found in large quantities in fatty fish, with numerous potential health effects, ranging from cardiovascular to mental well-being. Because omega-3s are known to play a key role in the growth and functioning of neural tissue, their effects on cognitive testing are always of particular interest to researchers. Fish consumption during pregnancy, or supplementation with fish oil, for example, is associated with improved neurological development in infants and young children, involving language, motor, visual, and coordination skills. A diet rich in fish products is also linked to better cognitive and academic performance in adolescents, and reduced cognitive decline and dementia in later life.
While studies in animal models have demonstrated the role of EPA and DHA on cognitive processes at a molecular level, knowledge on how to improve intellectual performance remains limited. One avenue that has yet to be explored is sleep and its link to cognitive function in adolescents, although insufficient or poor-quality sleep is known to be associated with poor school performance and lower learning and memory abilities. According to recent studies, sleep is influenced by omega-3 fatty acids through several mechanisms.
Studies have suggested the potential role of DHA in regulating the production of endogenous melatonin, a substance that regulates circadian rhythm and enhances sleep organization and Central Nervous System development in infants. In addition, omega-3s are involved in the production of prostaglandins, chemicals that act as mediators of inflammation and are believed to be the most potent endogenous substances for the promotion of sleep and sleep-wake rhythm regulation. Epidemiological studies have shown significant associations between increased fish consumption and improved sleep in adults, infants, and children. Despite evidence of a relationship between sleep and cognitive ability, no study has simultaneously examined how a diet rich in fish and omega-3 may affect sleep. Studies on dietary omega-3 consumption in school-age children and examining cognitive ability and sleep have been conducted almost exclusively in Western countries.
Higher intelligence test scores for children who consume fish
The new study aimed to address these gaps and examine fish consumption, sleep quality and cognitive outcomes in Chinese children. Thus, the purpose of this work is to examine whether a fish-rich diet improves sleep and outcomes in long-term cognitive tests. Research results showed that children who consumed fish regularly, at least once a week, performed better on intelligence tests, with I.Q. scores almost four points higher than children who never consumed fish products. In addition, fish consumption was also associated with improved sleep quality. These results suggest that sleep may mediate, at least in part, the relationship between fish consumption and cognitive abilities as measured by I.Q. In fact, according to the team of researchers, quality of rest may be a "missing link" between intelligence and omega-3 consumption from dietary sources and not from supplements.
Some details of the study
In the new study, led by Jianghong Liu Associate Professor at the University of Pennsylvania, 541 Chinese children (54 percent boys and 46 percent girls) between the ages of 9 and 11 were involved who filled out a questionnaire about how often they had consumed fish in the previous month. The children were also subjected to the Chinese version of an I.Q. test, called the Wechsler Intelligence Scale for Children Revised, which examines verbal and nonverbal skills. Parents, too, were asked about sleep quality, using a standardized questionnaire on children's sleep habits related to sleep duration, frequency of night waking and daytime fatigue. The analysis showed that children who reported consuming fish weekly scored 4.8 points higher on IQ exams than children who reported consuming fish that "rarely" or "never." Those whose meals occasionally included fish had scored 3.3 points higher. In addition, increased fish consumption was associated with fewer sleep disturbances-indicative of better overall sleep quality.
A groundbreaking study that needs to be completed
The new research shows for the first time that sleep may act as a mediator between frequent fish consumption and improved intellectual ability, providing an important mechanism by which a diet rich in EPA and DHA may influence cognitive functioning. These findings may have important public health implications for promoting healthy eating habits in children and adolescents. According to a co-author of the study, Jennifer Pinto-Martin, the research adds to a growing body of evidence showing that fish has "really positive health benefits" and how its consumption should be promoted. Due to the young age of the study participants, the team chose not to analyze details on the types of fish consumed-but, again according to the researcher, the team will continue this research by adding details to the current findings, to establish definitive links between nutrition, sleep quality, better school performance or other practical outcomes.
Source: Jianghong Liu, et al, "The mediating role of sleep in the fish consumption-cognitive functioning relationship: a cohort study." Nature's Scientific Reports
