R

onnie Wood isn’t feeling well. “Food poisoning,” he says, his voice gravelly, although he is over the worst. “I felt like I’d been through ten rounds with Mike Tyson.” A waitress hands him a coffee, his first in three days, which shows how unwell he has been. Coffee — strong, black, lots of agave syrup — is his signature drink. It’s what has kept him going since he gave up the booze and the drugs.

We’re not here to talk about the booze and the drugs, or even the Rolling Stones, for whom this 78-year-old has played rhythm guitar since 1975. We’re here to talk about art and philanthropy while the artist Hannah Shergold finishes his portrait in aid of the wildlife charity Tusk. “That’s coming along nicely,” Wood says, leaning over her canvas — she has perfectly captured his button-bright eyes and spiky black hair.

“Do you like the paintings?” he asks me, sitting down on a sofa and waving around him. He means his own art, gracing the walls of Ronnie’s Bar in the Nexus club in South Kensington, London — mostly portraits of his fellow band members, and celebrities such as Amy Winehouse and Jimi Hendrix.

“Nobody knows I paint,” he says, grinning and sitting forward. He doesn’t seem unwell at all. Rail-thin, yes. Suitably rock-star cool too, in a white shirt and navy tracksuit bottoms embroidered with the Stones’ lips logo. But he doesn’t behave like a rock star. He grins a lot, unselfconsciously; he arrived alone, with no entourage, and knows the names of the staff in the bar. He grins a lot at them too. They seem to like him.