Even when listed among the likes of Oprah Winfrey, George W Bush and Muqtada al-Sadr, the name of Dr Jacques Rossouw - French in origin, sure, but so distinctively South African - is bound to catch local eyes.

Okay, so he's not the leader of the most powerful nation in the world and maybe he's not heading a three-year insurgency against the army of the most powerful nation in the world, but Time magazine still thought Rossouw, a UCT medical graduate, worthy to be named among the 100 people it considers to be the most influential in the world today.

After all, as director of the Women's Health Initiative (WHI), based in Washington in the US, Rossouw's work impacts on at least half the world's population. The WHI has shown, in but one groundbreaking example, that oestrogen supplements, when combined with progestin as part of hormone-replacement therapy, increased women's risk of heart disease, stroke, dementia and breast cancer.

Rossouw landed in women's health almost by chance. Inspired by UCT mentor Dr Stuart Saunders, he says, his original speciality was in hepatology, researching disorders of the liver. That led to an interest in preventative cardiology and, while at the Medical Research Council, a major study into coronary risk factors among 7 500 volunteers in three Western Cape towns.

After a stint at the UCT Lipid Clinic, Rossouw moved to the US in 1989. In 1991, he was asked by the National Institutes of Health to, on behalf of its new initiative, the WHI, lead a definitive clinical trial on the links between postmenopausal hormone therapy and coronary heart disease among women, a study that he had proposed.

The rest is history.

Rossouw is taking his Time-inspired fame in his stride. "I see this as recognition of a landmark programme rather than the person," he says.

According to his son, Jacques Rousseau, a lecturer in the UCT School of Management Studies, Rossouw senior may appreciate the Time tribute, but it's not acclaim that inspires him.

"What drives him is doing his bit to decrease ignorance and confusion, and he'll continue to hold that committed attitude for as long as he's got something useful to say - regardless of whether it's appreciated or not."

No wonder Time thinks he deserves a place alongside presidents and billionaire TV hosts.