Want to know if your brain is younger or older than the number of birthday candles you tried to blow out last year? Stand on one leg and close your eyes. Do this close to a steadying wall or a friend to grab onto. (The grab is for safety — but we suppose you’d get some interesting reactions if you tried this in a singles bar.) The longer you can stand without losing your balance, the younger your brain is. If you’re 45 or over, 15 seconds is very good; if you’re 30 or so, 30 seconds is fine.
Another way to keep your brain young is by doing what we YOU Docs call "testing at the threshold." Let's say you can always do Wednesday's crossword puzzle, but you barely finish half of Sunday's. Keep taking a whack at the tougher Sunday puzzle (even if your ego likes the easier Wednesday one better). Just as athletes train their bodies by setting ever-harder goals, mental challenges train your brain to outmaneuver your nephew’s.
Your brain benefits hugely from healthy-body moves, too. So walk every day, and eat wisely: Choose healthy fats (not trans or saturated fats), avoid simple sugars and syrups, eat only grains that are 100% whole, and go crazy with fruits and veggies — at 9 servings a day, it’s hard to overdo ’em.