PhotoEverybody knows smoking is bad for you but an Australian study finds it's almost worse than bad. The of more than 200,000 people found that up to 2 of every 3 smokers will die of their habit if they continue smoking.

"We knew smoking was bad but we now have direct independent evidence that confirms the disturbing findings that have been emerging internationally, said lead author Professor Emily Banks, Scientific Director of the Sax Institute's 45 and Up Study and a researcher at the Australian National University.

"Even with the very low rates of smoking that we have in Australia we found that smokers have around three-fold the risk of premature death of those who have never smoked. We also found smokers will die an estimated 10 years earlier than non-smokers."

Until relatively recently it was thought that about half of smokers would die of a smoking-related illness, but newer studies in UK women, British doctors and Amercian Cancer Society volunteers have put the figure much higher, at up to 67%.

"We have been able to show exactly the same result in a very large population-wide sample," Professor Banks said.

Australia has one of the lowest smoking rates in the world - at 13% of the population and is an international leader on plain cigarette packaging. "But our findings are an important reminder that the war on tobacco is not yet won, and tobacco control efforts must go on," Banks said.

10 a day

The research also found that compared with non-smokers, smoking just 10 cigarettes a day doubles the risk of dying and smoking a pack a day increases the risk four- to five-fold.

The NSW Heart Foundation's CEO, Kerry Doyle, said the Australian Government was on the right path in driving down smoking rates through initiatives like tax increases and plain packaging.

"Higher tobacco prices have been shown to be the most effective intervention available to governments to reduce demand for tobacco. With smoking being a major cause of cardiovascular disease, including heart attack, stroke and peripheral vascular disease the more deterrents people have between them and smoking, the better,"  Doyle said.

The research was published today in the international journal BMC Medicine.