"It's brain," I said; "pure brain! What do you do to get like that, Jeeves? I believe you must eat a lot of fish, or something" P.G. Wodehouse
Eating fish has long been hailed as a way to boost brain function. Oily fish are a rich source of long chain omega-3 fatty acids, very similar to those found in the human brain tissue, and these fatty acids have been shown to have neuroprotective properties.
Perhaps then it is not surprising that the idea of eating more oily fish to allow the brain to replenish the fatty acids lost by the aging process has been suggested. Indeed a diet rich in oily fish has been linked to prevention of Alzheimer’s disease, and studies report an association of high fish intake and better cognition, a slower rate of cognitive decline or lower risk of dementia.
However these findings are not consistent across all studies. More recently reviews have been published that have looked at the impact of fish oil supplements on both cognitively healthy older persons, and persons with dementia, but these have shown no benefit on progressive cognitive function in either population group.
Fish oils and fatty acids supplementation though is not the same as consumption of fish. To what extent long chain omega-3 fatty acids contribute to a protective effect is still unclear, but it is likely that other components in the fish such as vitamin D or B vitamins may contribute to the beneficial effects. So it would still seem prudent to meet current government guidelines for fish intake which is at least two portions a week (140g each), one of which should be oily.
It should be noted though that fish portions actually consumed may be smaller than the 140g recommended, so care should be taken to meet the 280g total. And consideration should always be given to sustainable sources. Oily fish include salmon, trout, mackerel, sardines, pilchards, herring, kipper, eel and whitebait. These count as oily fish when they're canned, fresh or frozen.
And finally to end on another quote on the topic of fish and brains, that perhaps is a little less about nutrition but is nonetheless food for the soul.
Everyone is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.
*All information is correct at the time of publishing