Halle Berry, David Schwimmer, Samantha Fox and Chris Evans all turn 40 in 2006. It is a landmark birthday many celebrities would prefer the world to overlook. Of this quartet, it is perhaps the most famous of them all, Oscar winning Berry, who has the most to dread.
By Peter Bowes
BBC News, Los Angeles
Hollywood has a huge downer on women over 40.
Halle Berry will reach her 40th birthday on 14 August
With Berry seemingly still in her prime, stunningly good looking and much in demand, perhaps she will prove an exception to the rule. But Hollywood is littered with tales of aging starlets who see their careers take a nosedive after they pass the big 4-0.
"A perfect example would be Michelle Pfeiffer," says James Parish, a Hollywood historian and author of Katharine Hepburn: The Untold Story.
The 47-year old Scarface and Batman Returns actress has not had a leading movie role in years.
"She does very few films - not because she's not talented, not because she's not pretty in a mature way, but just because there aren't many parts for women over 40," says Mr Parish.
"Particularly when you're known for playing a sex kitten it's very hard to play that part when you're in your 40s."
Working Girl star Melanie Griffith, 48, is in the same boat.
"She deserves to work. She is a wonderful actress and Hollywood is pretty cruel with women that cross 40," says Griffith's husband, Antonio Banderas.
"Sometimes here you feel Hollywood just goes for fresh flesh. I know it's the economy and financial things but I feel bad for her because I feel they are misusing an actress who still has a lot of things to say."
Hollywood men tend to fare better although George Clooney, 44, has decided that his days in front of the camera are numbered.
"An acting career usually has about a shelf life of ten years before people get sick of seeing you," he explains.
"It's a good thing to have a job to fall back on and I really do enjoy directing."
Val Kilmer, 45, has plenty of work although he recognises Hollywood's "unforgiving" approach to ageing stars.
"It's a tough business, even if you're talented. I used to think it was full of hypocrisy but now I see it as a very honest town."
'Biased towards youth'
It is a town in the business of putting bums on seats. Young stars attract younger audiences and they appeal to advertisers.
"Most of the movie audiences are under 30 because older people have been discouraged from going to films," says Mr Parish.
"A lot of the films aren't very appetising to see. It's not very comfortable to go to the theatre with everyone screaming and yelling and it's just much more convenient with home entertainment becoming so much more sophisticated to remain at home."
Hollywood has always been biased towards youth. Ever since the early 1900s, with advancing years, A-list celebrities have seen their star power wane.
"Before the film stock that they used in cameras and lighting were very sophisticated people looked much older on screen than they were and so an actress, literally by the time she was in her mid 20s, was considered nearly a has been," says Mr Parish.
Michelle Pfeiffer has found it harder to get roles in recent years
"Eventually it worked out that by the 1930s a woman could be a star into her mid 30s or even her mid-40s. As we progressed past World War II and up to the present time it got to be a pretty standard rule of thumb that once a movie actress got to be over 40 then supposedly, psychologically, America's young kids didn't want to see her playing leading roles so they wrote fewer parts for them."
There are exceptions to the rule. At 59 Susan Sarandon's career does not appear to have been jinxed by being of a certain age. Four out of her five Oscar nominations came after the age of 40. She was named best actress for Dead Man Walking in 1996.
"She still plays leading roles, she plays mature women and she's able to find enough quirky roles and dramatic roles so that she's not reduced to guest starring or fifth billing," says Mr Parish.
Katharine Hepburn is also an example of an actress that bucked the trend.
"Up to the end she had a very strong physical stamina. And she happened to be possessed with great cheekbones so even though when she got into her 50s and 60s, she was not spring chicken anymore, she certainly looked very striking and appealing and she had this great vitality," says Mr Parish.