Sleeping for less than seven hours a night may increase the risk of fatal heart disease, a new study has warned.

A good night's sleep can increase the benefit of exercise, healthy diet, moderate alcohol consumption and non-smoking in their protection against cardiovascular disease (CVD), according to results of a large population follow-up study.

Results showed that the combination of the four traditional healthy lifestyle habits was associated with a 57 per cent lower risk of cardiovascular disease (fatal and non-fatal) and a 67 per cent lower risk of fatal events.

But, when "sufficient sleep" - defined as seven or more hours a night - was added to the other four lifestyle factors, the overall protective benefit was even further increased - and resulted in a 65 per cent lower risk of composite CVD and a 83 per cent lower risk of fatal events.