Paris: Just one cigarette a day carries nearly half the risk for heart attack and stroke as smoking a full pack of 20, according to a large-scale study published Thursday.
"If someone smokes one cigarette instead of 20 per day, intuitively we'd think that the risk drops to 1/20, or five percent," said lead author Allan Hackshaw, a professor at University College London, whose paper analysed 141 previous studies.
"This seems to be the case for lung cancer, but is not true for heart attacks and stroke, where one cigarette per day carries around 50 percent of the risk of a pack a day," he told AFP.
Smokers should not be fooled, in other words, into thinking that a few cigarettes a day -- or even just one -- carries little or no long term harm, he added.
"Whilst it is great that smokers try to cut down -- and they should be positively encouraged to do so -- in order to get the big benefits on cardiovascular disease they need to quit completely," he said by email.
Tobacco kills about seven million people worldwide every year, according to the World Health Organization.