Everyone slows up, some at faster rates than others for a variety of different reasons. Some it may happen so slowly they don't even realize it happened, but it will for everyone.
I'm not a woman, so I can't speak on women but as a dude, eating/drinking a lil better, watching your weight, maintaining stress levels, etc...all play a factor.
Honestly too, being sexually active is a big plus here too. For lack of a better description, keeping your pipes clean and flowing will keep your pipes clean and flowing.