James D'Arcy is petrified of ageing after starring in 'Cloud Atlas'.

The 'Hitchcock' actor has gone on a health kick since playing Rufus Sixsmith - one of his many alter egos in the Wachowski siblings and Tom Tykwer's multi-layered film - because he didn't like the way he looked as an old man thanks to the advanced prosthetics and make-up.

Speaking at the gala screening of 'Cloud Atlas' at the Curzon Mayfair Cinema in London on Monday night (02.18.13), he joked to BANG Showbiz: ''Playing the old man was really horrendous because I could see that I might end up looking like that. I immediately went out and bought a juicer and started taking yoga lessons because I was desperately trying to stave off the ravages of time.''

The British star revealed the extreme makeovers were so convincing he couldn't even recognize his A-list co-stars - who include Tom Hanks, Halle Berry, Hugh Grant and Jim Broadbent - when they were sitting right next to him.

James laughed: ''You did sometimes sit down in make-up and if the person next to you didn't speak, it could be five minutes before you were like, 'Oh my God, that's Hugh Grant!' That did happen a lot actually.''

Nevertheless, the actor relished the challenge of taking on different kind of roles - which also included a female nurse - and found working under a heavy prosthetics mask much more enjoyable than he had anticipated.

He said: ''It was a new challenge that I hadn't encountered before. I'd done little bits, but not for an extended sequence. They don't move like normal faces do and they're better in the afternoon because they're warmer and they're sort of peeling off at the edges.

''The filmmakers don't like it, but from an actor's perspective it's a bit easier, so it's a really interesting new discipline to try and learn.''

Hugh Grant, Jim Sturgess and Ben Whishaw joined James on the red carpet for the film's UK premiere.