by Marlowe Hood PARIS, France (AFP) — 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. […]