My experience has been just the opposite actually. mid to late 30's is where most of the attention i get comes from.
This is because many women are really horny in their mid to late 30's. For many it is getting close to their last chance to get pregnant, which might play into this physiologically. It is also possible they are a little less romantic at this point in their lives.
Many women today see having a younger lover as a conquest which previously was reserved for men. Also, more women are independent by this time, either because of divorce or because they are pretty well established in there jobs.