When you look at the cover of a magazine in the grocery store (and the picture isn't Dr. Oz), do you ever mutter, "Who's that?"

It could just be a matter of generational "Star Gaposis." Your granddaughter couldn't pick Barbra Streisand out of a lineup, and you haven't a clue about who Amanda Bynes is.

But there are specific memory lapses that indicate you are at risk for early-onset dementia (before age 65). Not being able to name famous folks that you once recognized is one indicator.

In a recent study, people with early-onset dementia recalled the names of only 46 percent of once-familiar celebrity faces. Another study identified factors in teenage boys that lead to early-onset cognitive problems: drug abuse, depression, high blood pressure, having a father with dementia and poor mental function. Having two of those traits -- say, high blood pressure and depression -- makes a teen 20 times more likely to develop dementia before age 65.

But, young or not-so-young, you can take positive steps to protect your brain. Keep your cardiovascular system healthy. Physical activity (10,000 steps a day) and stress reduction (meditate 10 minutes two times a day) build brain size, keep neural connections healthy, and lower blood pressure.

So does eliminating the Five Food Felons -- no trans or saturated fats, no added sugars or sugar syrups and no grain that isn't 100 percent whole. Build new neural pathways. Increase brain strength with a new hobby, reading, playing intriguing games, staying engaged and interacting with people. Now you're thinking.

© 2013 Michael Roizen, M.D. and Mehmet Oz, M.D.
Distributed by King Features Syndicate, Inc.