there is always lipo-sculpture, where they suck the fat out to give you ab lines. Although i saw some guy on tv who had it done, and he was so impressed with his own "six pack" that he ran shirtless on tv. All i can say is real abs don't bounce when you run, plus the "surgeon" had put the side lines way too far out, so it looked really wrong.
and 35 (like myself) is not "a certain age" there are plenty of guys on this site who are in their 40's and even 50's (and beyond) who still have great abs.
like the others have said, abs come from the kitchen. cut out processed sugars and foods.
check out the glycemic index
. it has to do with how fast sugar is processed by your body. high GI foods will cause your blood sugar to spike, while low GI foods, tend to last longer.