"Fish is brain food" is the kind of age-old folk wisdom that's been proven time and again by cutting-edge science -- and the latest research confirms that the best way to keep your brain swimming in gray matter is with a steady diet of fish.

I mean that literally: Seniors who eat fish at least once a week have more of that critical gray matter, giving them a lower risk of dementia and Alzheimer's disease.

The biggest boost is in the frontal and temporal lobes -- specifically the areas most closely linked to memory and learning, or exactly where you want your extra gray matter to be.

And if you think the benefits inside the brain are impressive, you should see how that translates out in the real world: Just 3.2 percent of the fish-eaters developed cognitive decline over five years, versus 30.8 percent of those who ate little to no fish, according to data presented at a Radiological Society of North America meeting.

If there's one area where the researchers found no benefit, it was in fried fish -- and I have to wonder if it's because of the frying... or because of the oils people tend to fry things in.

Most people don't fry their foods -- fish or otherwise -- in healthy oils. They fry them in the unhealthiest polyunsaturated oils of all, including blended vegetable oils, soybean oil and safflower oil.

Try a healthier oil -- like peanut oil -- and all your fried foods will get a health boost (and taste better, too).

But let's get back to seafood, cooked however you like -- because a diet rich in fatty fish will do so much more than protect your brain. Fatty fish can help prevent heart disease, protect your vision, beat depression and even improve your gums.

Yet despite all those benefits, some simply won't eat fish to save their lives. Maybe it's the smell... the taste... the texture... or all three.

Whatever the reason, you don't have to actually eat any fish at all to get the benefits -- because almost all of those benefits come from the omega-3 fatty acids found in fish oil, which you can find almost anywhere as a supplement.

Shop around before you commit to one -- some brands will leave you with the "fish burps," which is a little counterproductive if you're taking pills to avoid the taste of fish in the first place.

Buy smaller sizes or sample packs first -- it might take a little trial-and-burping, but eventually, you'll find one that works for you.