Smokers in their thirties and forties have five times as many heart attacks as non-smokers, according to the largest British study to date involving almost 14,000 survivors.
The findings show that both low- and medium-tar cigarettes substantially increase the risks of heart attacks at all ages. The report, in the British Medical Journal, says that "irrespective of whether low- or medium-tar cigarettes are used, about three-quarters of smokers in their thirties, forties, and fifties, need not have done so. . . "
Dr Rory Collins, of the clinical trial service unit at Radcliffe Infirmary in Oxford, which supervised the research, said: "This huge study shows there is no such thing as a safe cigarette - they're all good at killing you.
"The younger you are, the bigger the proportion of heart attacks caused by tobacco. When cigarette smokers have a heart attack in their thirties or forties, there is an 80 per cent chance that tobacco caused it."
For those aged 50-59, the corresponding figure is 66 per cent, falling to 50 per cent at age 60-79.
The researchers analysed smoking behaviour and blood profile data from 13,926 heart attack patients discharged from British hospitals over five years and 32,389 of their relatives.
They found that for people aged 30 to 39, the risk of heart attack in smokers was about five times that in non-smokers. For those aged 50-59, the risk was about three times greater for smokers, and even at ages 60- 79 there was a twofold risk.
Although heart attacks appeared to be more common among smokers who favoured medium-tar cigarettes, the difference in risk between smokers and non- smokers was far greater than any differences in risk between one type of cigarette and another.
The researchers concluded that far more heart attacks could be prevented by not smoking than by changing from one type of cigarette to another.
However, they point out that a cigarette with a maximum tar yield of 12 milligrams now being introduced in the European Union to reduce the cancer risk is unlikely to increase the incidence of heart attack and may well decrease it.
Professor Richard Peto of the Imperial Cancer Research Fund, who took part in the study, said: "If you happen to survive your first heart attack, then stopping smoking still makes you much less likely to have another.
"But stopping before you've had a heart attack is even better. Smoking causes about two dozen diseases. Overall, about half of all persistent cigarette smokers eventually get killed by tobacco."
t Women who smoke during pregnancy have a greater risk of dying prematurely from tobacco related-diseases, such as lung cancer, and accidents and suicides, according to a report from Finland in the British Medical Journal.Reuse content