Just over 25 years ago, the British Medical Journal published a study that suggested a single cigarette could shorten a smoker’s life by 11 minutes. Unsurprisingly, this caught the attention of the media, and the figure spread far and wide – the trouble was, the study had some pretty significant flaws. Now, new research has accounted for them and come up with a new estimate: smoke just one cigarette, and your life could be 20 minutes shorter.
One of the main problems with the original study lies in the sample of people it used – it was exclusively male, with the estimate of mortality in particular only based on data from British male doctors. The findings of the research were interesting, sure, but they certainly couldn’t be applied to the public more widely.
The new study, from a team at University College London, made use of a wider pool of data. It included more up-to-date male doctor mortality figures from the British Doctors Study plus female mortality data taken as part of the Million Women Study – both of which adjusted for other factors that can affect mortality, like socioeconomic status and physical activity.
After doing so, the researchers found that male smokers lost approximately 10 years from their life expectancy, while female smokers lost 11. Factoring in the average number of cigarettes smoked per day, the authors write that “this would lead to an increase in the estimated loss of life expectancy per cigarette to 20 minutes overall: 17 minutes for men and 22 minutes for women.”
Though it’s arguably an improvement upon the earlier study, the authors of the new study are careful to note that their research also has caveats, the main one being that the estimate is based on averages – such as of smoking pattern and type – across populations and ages.
For example, while smoking is undeniably one of the biggest preventable causes of premature death, disease, and disability, there’s a little truth to the claims made by your mate down the pub whose grandad smoked a pack a day and lived until he was 93. As the authors write, “Some smokers live long and healthy lives while others succumb to smoking-related diseases and even death in their 40s.”
They also made the assumption that smokers smoked the same number of cigarettes per day across their lifetime and noted that not every cigarette smoked would affect someone in the same way each time.
Their highlighting of such caveats, however, isn’t positioned as a green light for people to carry on smoking, or just smoke a bit less. “The health risks of smoking are not linear,” they write, “and it is not enough just to reduce consumption – total cessation is required to achieve the maximum benefits for health and life.”
“This is time that would likely be spent in relatively good health. Stopping smoking at every age is beneficial but the sooner smokers get off this escalator of death the longer and healthier they can expect their lives to be.”
The study is published in the journal Addiction.
The content of this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.
