Older people who quit smoking may lower their risk of suffering a heart-related death faster than previously estimated, a new study has found.

Previous research has shown that among quitters, it can take up to 15 years of no smoking for them to lower their heart disease risk profile to that of a non-smoker. However this latest study suggests that for some, this figure may be closer to eight years.

US scientists compared over 850 people who had quit smoking within the previous 15 years, with more than 2,500 non-smokers. All were aged over 65.

When it came to how much the ex-smokers had smoked, the scientists focused on ‘pack years', which are worked out by multiplying the number of cigarette packs smoked each day by the number of years a person has smoked.

Among the ex-smokers, 318 had smoked less than 32 ‘pack years', which is equivalent to 3.2 packs, or just over 60 cigarettes, per day.

The study found that among those who smoked less than 32 pack years, and who had given up smoking less than 15 years ago, reduced their risks of developing heart failure or dying from heart failure, a heart attack or a stroke.

Many of the people in the study achieved this within an average of eight years.

However, the scientists from the University of Alabama did note that ex-smokers who smoked less than 32 pack years still had an increased risk of dying from non-heart-related diseases, such as cancer and emphysema.

Meanwhile, ex-smokers who had smoked more than 32 pack years had an increased risk of dying from all health conditions.

The scientists commented that smoking is ‘the most preventable cause of early death'.

"If you smoke, quit and quit early," they said.

Details of these findings were presented at the American Heart Association's Scientific Sessions 2013.

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