I love a good mystery -- and there's one brewing right now in the world of coffee.

You've probably already heard that java can help protect you against everything from dementia to Parkinson's to colon cancer.

Now, a new study has found two ingredients in particular that seem to work together to protect you against Alzheimer's disease. One is caffeinate, and the other is...well, that's where the mystery comes in.

Previous research had shown that pure caffeine itself improved cognition in mice with symptoms of Alzheimer's. But according to the results of this latest study, caffeinated coffee could give you an even bigger brain boost than caffeine alone. Take a look...

Researchers from Tampa's University of South Florida gave mice either pure caffeine, regular coffee, or decaf coffee. They found that mice that got the "real" brew had the highest blood levels of granulocyte colony stimulating factor, or GCSF.

That's a protein that plays a key role in the immune system. High levels of it has also been linked to better memory, and low levels have been tied to Alzheimer's.

It's no wonder GCSF is such a powerhouse. The researchers say that it benefits your brain in three different ways.

First, it suppresses the production of beta amyloid, the plaque that is believed to be the cause of Alzheimer's. But
it doesn't stop there. GCSF also goes to work destroying any existing beta amyloid. Finally, it produces connections in your brain, and encourages the birth of new brain cells.

Since pure caffeine alone didn't produce the same surge in GCSF, researchers believe it's the combination with the "mystery ingredient" that provides the boost.

Coffee -- especially espresso -- is also one of the top natural sources of niacin, a key vitamin that can help prevent heart attacks and stroke.

One recent study found women who drank more than a cup a day had a 25 percent lower risk of stroke than women who drank no coffee.

And of course, one of coffee's most notable effects on your brain is its ability to wake it up each day. I know my own
always seems to function just a little bit better after the second cup.