Julia Roberts has joked she “pickles” her head for 36 hours a month to maintain her youthful looks.

The ‘Pretty Woman’ actress, who turned 56 in October, made the admission in a cover interview for British Vogue in which her ‘Notting Hill’ director friend Richard Curtis, 67, quizzed her on what he said were her “seven faces” – which he reckoned ranged from her “famous face” and “career face” to her “feminist face”.

When the filmmaker asked her about her physical appearance and the secret to her youthful appearance Julia put it down to her family, telling Richard: “I don’t know your parents – I’m sure they were lovely people. But my parents? Both very good genes.”

She also admitted she thinks she looked far younger at the peak of her movie career, saying: “Not to say I’m unchanged, because I did see a picture earlier of Tom Hanks and me from a movie, and we looked like we had been ironed.”

When Richard told her Vogue readers “will want to know whether or not you use any artificial methods to preserve your lustrous youth”, Julia joked: “Pickling. I put my head in the jar every other Saturday for 18 hours. It does wonders. The smell is awful.”

She then added: “No – serious answer. Good genes, leading a life that is fulfilling, and I have said this – and I say it usually as kind of a joke – but I do believe in the love of a good man.”

Julia has been married to Daniel Moder, 54, since 2002 and has three children with the cinematographer – twins Hazel and Phinneas, 19, and 16-year-old son Henry.

She added about her and Danny’s relationship: “I believe that my husband loves me and cares for me in a way that makes me feel deeply, deeply happy. And anytime you see someone who’s happy, it doesn’t matter how old they are.”