Once a week. That's all it takes -- a delicious fish dinner just once a week.

Make it a tradition in your home, and you'll have more than a meal the whole family will be looking forward to every week.

You'll give your brain big-time protection against one of the diseases seniors fear most!

New research shows how the omega-3 fatty acids found in fish not only protect the brain -- as we already know -- but that the benefits kick in with just a single fish dinner a week.

Seniors in the new study were tracked for five years, and over that time the folks who had fish at least once a week had slower declines in key parts of the brain.

They did better on tests of semantic memory, which is a critical part of your long-term memory. It's what helps you remember things you've learned rather than things you've done -- where you store the fact that London is the capital of England or that a year is 365 days long.

The fish-eating folks also had a slower decline in perceptual speed, or your ability to make quick comparisons and recognize patterns.

Think that's good? That's only the beginning.

Like I said, we already know the omega-3 fatty acids in fish are just terrific for the brain, so the results aren"t too surprising.

What IS worth noting here is that this study goes even further and spots who can benefit most. And it's exactly who needs it: folks who are ALREADY facing a higher risk of Alzheimer's disease.

There's a gene variant called APOE -- and, depending on which variant you have and whether you have a copy from one or both parents, it could increase your risk of Alzheimer's by as much as 10 times.

This doesn't mean you're doomed to get the disease, but it does mean you have a higher risk -- and when you have a higher risk, it's even more important to take action to bring it back down.

A simple and delicious fish dinner just once a week will do the trick, because the new study finds folks who carry the gene show the biggest improvements of all.

But whether or not you have that gene, fish oil can still help -- and with more than just memory protection. It can also save your vision, boost your mood, and even prevent a heart attack.

Just be sure to make smarter choices with your seafood to limit your exposure to mercury and PCBs. For example, wild-caught salmon from Alaska is much healthier and has fewer toxins than farmed fish.

And while once a week is clearly enough to make a big difference, you can get even more protection by taking a quality fish oil supplement every day