A study published in December 2017 by Pennsylvania University found that, “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.” and discussed the link between fish, better sleep and IQ. (Source: EurekAlert!, the online, global news service operated by AAAS, the science society.)
In Tibb (Islamic Medicine), fish is classified as having cooling and moisturizing properties: food qualities.