London: Smoking matters more than money and class in determining how long you will live, researchers said.

Smokers from the highest social class are more likely to die early than non-smokers in the lowest class. And smoking also wipes out the longevity advantage that woman normally have over men.

The findings came from a massive study involving more than 15,000 men and women in Paisley and Renfrew. Carried out over the course of 28 years, the findings are reported today in the online edition of the British Medical Journal.

The researchers found that a well-off professional who smokes has a far lower survival rate than a non-smoking low-paid worker of the same sex. Among both men and women, smokers of all social classes ran a much higher risk of dying early than non-smokers from the lowest social classes.

“In essence, neither affluence nor being female offers a defence against the toxicity of tobacco,” said the researchers, led by Dr Laurence Gruer, director of public health science with NHS Health Scotland.

The findings also suggest there is little scope for reducing class-related health inequalities unless smoking rates in the lower social classes can be reduced.

The study began with 8,353 women and 7,049 men aged 45-64 in the early 1970s. These were then divided into 24 groups – male or female, smokers, ex-smokers or never-smokers – and all categorised in one of four social class headings.

After 28 years, 56% of non-smoking women and 36% of non-smoking men in the bottom two social classes were still alive – compared with only 41% of women smokers in the top two classes and 24% of men.

The researchers also found that most deaths from lung cancer were among smokers. There were 842 deaths from lung cancer – 5% of them among those who had never smoked, 9% amongst former smokers, and 86% among current smokers.

The researchers also found that the death rate for ex-smokers was similar to those who had never smoked, suggesting that quitting can make a significant difference regardless of status.