There may "B" an answer to Alzheimer's after all--and it might even be something you're taking right now.

Researchers have found that high levels of three common B vitamins can dramatically slash the brain shrinkage associated with dementia and related conditions.

Naturally, they're already hoping to sell this to you as a "drug," but you don't have to wait for Big Pharma's blessing--because the ingredients are sitting on the shelf at your local vitamin store right now, and I'll tell you all about them in a moment.

But first, let's take a look at this remarkable new study.

Researchers recruited 168 seniors who suffered from mild cognitive impairment and assigned them to either a placebo or TrioBe Plus--a patented blend of vitamin B6, vitamin B12 and folic acid.

After two years, MRI scans revealed that those who had been taking the B vitamin blend had a much slower rate of brain shrinkage: .76 percent of volume per year, versus 1.08 percent in those who were given the placebo, or a difference of 30 percent.

What's more, patients with the highest blood levels of the inflammation marker homocysteine at the start of the study had a 53 percent reduction in the shrinkage rate, according to the study in PLoS One.

By the way, here's a humbling piece of trivia: All of our brains are shrinking. Even the healthiest ones lose about half a percent each year. Just a guess, but they may end up in the same place as keys, wallets and left socks.

Now, before you run off to try to slow your own shrinkage with some B vitamins, the researchers behind this study have a warning: Their blend, they say, is a high-dose "drug" and should only be given under the care of a doctor.

But that sounds a lot like patent-protecting greed to me, because one look at the TrioBe Plus ingredients label reveals that these high doses aren't so high after all: 800 micrograms of folate, 500 micrograms of B12 and 20 milligrams of B6.

They're high levels in that they exceed the U.S. government's lowball recommended daily intakes... but not so high that they can't be found without a prescription. In fact, you can pick them up at almost any supermarket or health food story in those exact amounts.

Since your own needs could vary depending on your age and condition, talk to a naturopathic physician about the best ways to add some B to your regimen now--but don't be afraid to do it.

And don't be afraid to start today--before your brain shrinks even more than it already has.