The 49-year-old told Life & Style magazine that she currently undergoes "oxygen facials" to keep herself looking young.
"'I swear by oxygen facials, and I'm obsessive about staying out of the sun," she said. "I'm not against plastic surgery - I'm just against discussing it."
The pop icon was also quick to quash rumours that she is about to split from husband Guy Ritchie.
"I've got work to do, children to raise, a husband to please and a world to save," she said.