The slogan “smoking kills” might sound like something that applies to an unlucky few, but as many as two out of every three smokers will die from the habit if they fail to give up.
According to a study of 200,000 people in Australia, smoking just 10 cigarettes a day doubles the risk of dying, while smoking a pack a day increases the risk four- to five-fold.
It is the first evidence from a broad cross-section of the population to show such extreme numbers, and it estimates that smoking cuts an average of 10 years off a person's life.
"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 from 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."
The research, published today in the international journal BMC Medicine, is based on a four-year study of both men and women.
Until recently, it was believed that smoking would be the ultimate demise of around half of those who did it, but this new investigation indicates the proportion is much higher, up att 67 per cent.