I think this must be old news. I recall one of P.G. Wodehouse’s novels in which Bertie Wooster ascribes Jeeves’ braininess to Jeeves’ regular consumption of fish.

Hope it’s not too late for putting off dementia. Perhaps the rest of us can benefit, though. Thanks!

Or just buy salmon oil capsules and consume them regularly. Unless you like fish. . .

Of course, if you eat the fish the mercury will get you (or so say the "experts" out here in California). This stuff can drive you crazy.