Fresh sardines make a healthy, nutritious, economical meal. Yes indeed. The big drawback to tinned sardines is the added salt, but if you buy fresh and cook them yourself you can avoid adding salt. If you've not cooked sardines before, there are many internet sites that give good instructions about this. One site I thought extremely clear to follow is this one. I bought half a kilo of fresh sardines with my last supermarket order and that cost only £1.50.
When I was a child I was always being told that fish is good for the brain and I'm sure that's as true today as it was then. Being small fish at the bottom of the food chain, they do not carry the mercury contamination dangers that bigger fish do. They are oily fish, packed with healthy nutrients: protein, omega-3 fatty acids, vitamin D, vitamin B12 and other B vitamins, vitamin E and calcium. They don't contain carbohydrate. And of course they cook very quickly. - Why not give them a try? They are very tasty and they are good for you - and good for your brain!