A team from the University of Pennsylvania's School of Nursing published a study this week which has proved that the weekly consumption of fish is linked to having a higher IQ. Children who eat fish every week have an IQ that is four points higher, on average, than those who consume fish infrequently or not at all. The study revealed that eating fish improves sleep which leads to higher mental capacities.
Previous studies clarified the link between the consumption of omega-3, the fatty acid found in many types of fish, and a higher IQ, as well as links between omega-3 and better sleep. However, this is the first study that has discovered that all of these links are connected.
For the study, a group of 541 children in China, aged nine to eleven, were asked how often they ate fish. The options ranged from “never”, to “at least once a week”. These children, 54 per cent of whom were boys and 46 per cent girls, were then assessed via the Chinese version of an IQ test called the Wechsler Intelligence Scale for Children-Revised, which examines non-verbal skills such as vocabulary and coding. The parents of the assessed children answered questions about their children's sleeping habits, including how long they sleep for, and frequency of waking and daytime tiredness. The researchers took into account parents' occupation and marital status, and number of children in the home.
Analysing all of the data, the team found that the children who said that they ate fish weekly scored 4.8 points higher in the IQ test than the children who said they “seldom” or “never” ate fish. Those who “sometimes” consumed fish scored 3.3 points higher. Additionally, increased fish consumption was associated with fewer disturbances of sleep, which indicates better sleep overall.
“Lack of sleep is associated with antisocial behavior; poor cognition is associated with antisocial behavior,” said Professor Adrian Raine. “We have found that omega-3 supplements reduce antisocial behavior, so it's not too surprising that fish is behind this.”
Jennifer Pinto-Martin, member of the research team, stressed the importance of children being introduced to fish as part of their regular diet from a young age, from around two years old. “Fish consumption has really positive health benefits and should be something more heavily advertised and promoted,” she said. Pinto-Martin pointed out that if children are fed fish early on then they get used to the smell and taste, which children can find unpleasant if unaccustomed to it.
Further developments on this research would involve looking into the types of fish consumed, and whether this affects IQ and quality of sleep. This study would be done on an older test group as they are likely to have a greater variety of fish included in their diet. The team also want to find out what other positive effects fish may have on school performance and social abilities.
Families in Malaga, due to the province's being on the coast, tend to consume a diet that is high in fish. According to this study, eating fish once a week is considered “high consumption”. For children whose diets are low in omega-3, the research team highly recommends incrementally incorporating more fish into a diet.
“Doing that could be a lot easier than nudging children about going to bed,” Raine commented. “If the fish improves sleep, great. If it also improves cognitive performance, like we've seen here, even better. It's a double hit.”