A newly published study* on the linkage between tobacco consumption and mortality has shown that up to two-thirds of deaths in Australian smokers can be attributed to the habit.
Further, current smokers are likely to die a decade earlier than non-smokers.
“Cessation reduces mortality compared with continuing to smoke, with cessation earlier in life resulting in greater reductions,” the research team* concluded.
The report drew on data contained in the milestone 45 and Up Study involving 204,953 NSW residents aged ≥45 years who joined thd study from 2006–2009.
“The smoking epidemic in Australia is characterised by historic levels of prolonged smoking, heavy smoking, very high levels of long-term cessation, and low current smoking prevalence, with 13% of adults reporting that they smoked daily in 2013,” the BMC Medicine article noted.
“Overall, 5,593 deaths accrued during follow-up... 7.7% of participants were current smokers and 34.1% past smokers at baseline... Mortality RRs [relative risks] increased with increasing smoking intensity, with around two- and four-fold increases in mortality in current smokers of ≤14 (mean 10/day) and ≥25 cigarettes/day, respectively, compared to never-smokers.
“Among past smokers, mortality diminished gradually with increasing time since cessation and did not differ significantly from never-smokers in those quitting prior to age 45. Current smokers are estimated to die an average of 10 years earlier than non-smokers.”
Study leader ANU Professor Emily Banks told media that, "In a smoking epidemic, the risk evolves all the time. In the 1960s, when people started smoking later, they used to say it was like rolling a dice, and there was a one in six chance you would die from it.
"In the '80s and '90s it was like flipping a coin… we are now only fully realising the impact of smoking… The people who smoke now have started at a much younger age and have smoked for many decades."
In short, people who smoked an average of 10 cigarettes a day were more than twice as likely as non-smokers to die prematurely, and the heavier the smoker, the greater the risk of death.
Even those who only smoke five cigarettes a day had a 70 per cent increased chance of dying.
"Even people who would consider themselves to be light smokers are running a large risk," said Prof Banks, the 45 and Up scientific director, adding that quitting at any age provides huge health benefits, and the earlier a person did it, the better.
"For people who quit by the age of 45, and that means before 45, their risks are similar to someone who has never smoked," she said.
Public Health Association of Australia chief executive Michael Moore said, "This confirms that smoking is still our single most preventable cause of death and disease – and kills even more smokers than we had thought. It also emphasises the risks of even light smoking."
* Tobacco smoking and all-cause mortality in a large Australian cohort study: findings from a mature epidemic with current low smoking prevalence.
Emily Banks, Grace Joshy, Marianne F Weber, Bette Liu, Robert Grenfell, Sam Egger, Ellie Paige, Alan D Lopez, Freddy Sitas and Valerie Beral.