A better diet, more exercise and quitting smoking can do more to reduce the risk of stroke in Australians than surgery.

Carotid artery stenosis occurs when fatty "plaques" build up in the neck arteries that help deliver blood to the brain.

A new study from Monash University shows lifestyle changes and medication will reduce stroke risk just as much as, if not more than, invasive surgery.

Carotid artery surgery or the installation of stents - inserting a tube to keep the arteries flowing - are still common measures for reducing stroke risk.

But study author Anne Abbott said the procedures often cause more harm than good.

"People need to understand that they have the greatest power to prevent their own stroke," Associate Professor Abbott said.

"Healthy life habits, including physical activity, diet and quitting smoking, combined with appropriate medication, help mitigate major risk factors."

These risk factors include high blood pressure and cholesterol.

Stroke risk in people with advanced carotid stenosis fell by at least 65 per cent in those taking non-invasive measures.

The study says this is the same as, or better than, the stroke rate in patients who underwent surgery.

"Stroke rates are now so low with non-invasive intervention alone that carotid artery procedures are unlikely to provide benefit to the vast majority of patients and have no current proven benefit for any patient," Assoc Prof Abbott said.