The Mediterranean diet is absolutely proven to prevent heart disease, and it reduces absolute risk by about one-third.

So whatever your risk of a heart attack, if you switch from a predominantly high-fat, low vegetable, low olive oil diet to a Mediterranean diet with nuts and legumes, you will reduce your heart attack risk over the subsequent 5 years by about 30%.

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