On average, a single cigarette takes 20 minutes off a person’s life, according to a new study published at University College London. To put that into perspective, a pack of 20 cigarettes can shorten a person’s life expectancy by seven hours.
The estimated shortened life expectancy is more than what researchers first predicted in 2000, when they found that a cigarette can shorten a smoker's life expectancy by an average of 11 minutes. The data published in Addiction follow up on the 2000 study published in BMJ. It draws from data from the British Doctors Study, which started in 1951 as one of the largest studies looking at the effects of smoking. It also pulls from data from the Million Women Study.
