I know plenty of seniors who would pop pretty much any pill -- risks and costs be damned -- if it meant they'd never have to battle Alzheimer's disease.

But it turns out they may not have to face any risks at all to get a leg up on dementia -- because the latest research confirms that simple, safe and widely available B vitamins can dramatically slow the rate of cognitive decline.

Researchers gave 266 men and women older than 70 either a placebo or a blend of B vitamins -- 0.5mg of B12, 0.8mg of folic acid, and 20mg of vitamin B6 -- and tracked them for two years.

Those who got the real vitamins did 70 percent better on memory tests than those who took the placebo. They improved in just about every way, with real boosts in semantic memory (the memory of facts and concepts) as well as overall global cognition.

And the biggest boost of all came in "episodic memory," or the part of the mind we use to remember our daily tasks. That's the first part of the mind to go in dementia patients, so you can see why these results are so exciting.

The good news doesn't stop there: In some cases, patients who were already battling memory lapses before the study actually improved their memory after two years of B vitamins.

The researchers say the biggest benefits were seen in patients with the highest levels of homocysteine at the start of the study. (Homocysteine is an inflammation marker with strong links to dementia, heart disease, and more.) Those benefits went well beyond anything measured on cognitive tests.

In fact, patients who took the vitamins had real and visible changes in the physical structure of the brain itself.

Before I get into that, a little background: All our brains shrink a little as we age. It's a frightening thought, but it's perfectly normal.

In dementia patients, however, the brains often shrink at a much faster rate -- so researchers believe anything that can slow that loss of gray matter may also slow or stop the disease itself.

And the vitamins were able to slow that loss of gray matter by an average of 30 percent overall and 50 percent in those with high homocysteine levels -- with one patient seeing a shocking improvement of 500 percent.

It's clearly too early to say whether B vitamins can stop or even slow Alzheimer's disease. But it's also pretty clear you need more of the Bs than the tiny levels the powers-that-be recommend -- so talk to your doctor today about adding a B complex to your regimen.