I think is the other way round;
Men are attracted to younger women...that should make sense after all women fertility shuts down at around 48 on average.
Men in theory can father at any age as long as they can get their "old equipment" to work. Clint EAstwood fathered a girl at 68 if I remember well.
Having said that, humans are more than animals, so it should not be all biology.
Before Demi Moore, they were quite a few "oldies" that conquer younger men. My favorite is Berenice, from today Israel, who at 38 conquered the hearth of Tito (26) son of Vespasiano the Roman Emperor. They stay together for over 16 years (i.e.,42 Tito to 54 Berenice). Tito left her to replace his father in the throne, but lived only for two more years, and never fall in love again.
That was quite a success for Berenice, and without the help of modern make up, or plastic surgery, or diet, or the gym.