Cameron Diaz, Gwyneth Paltrow, Ben Affleck and more! See the seemingly ageless A-listers celebrating 40th birthdays this year
Jennie Garth (April 3)
Better after breakup -- and the big 4-0! The newly single Beverly Hills: 90210 star, who parted ways with husband Peter Facinelli in early 2012, recently debuted a jaw-dropping post-split slimdown.
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