So once an artery is clogged with cholesterol, it’s like a pipe in your plumbing system, that’s got a blockage in it. It’s a mechanical problem and it needs a mechanical solution. So with diet and exercise, you can stop a plaque growing further, and you might be able to shrink a plaque but probably only by about 5 or 10%. So in people with a blockage in their arteries that’s causing them a problem the solution is usually either a stent or a bypass operation.

Professor David Celermajer is Scandrett Professor of Cardiology and Head of Cardiology at the University of Sydney.