Longevity Briefs: The True Price Of A Cigarette

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

We all know that smoking is terrible for your health. If you are a smoker, quitting is the single most cost-effective lifestyle intervention for extending both lifespan and healthspan (the number of years spent in good health). Previous studies have attempted to estimate how much time each cigarette shaves off your lifespan. In 2000, the British Medical Journal put forward the figure of 11 minutes of life lost per cigarette smoked. However, this estimate was based on data with some important limitations, as it is now over 30 years old and came exclusively from data relating to male doctors. Now that more complete and up to date data is available, what does the cost of a single cigarette look like?

The discovery:

In this publication, authors looked at data from two studies: the British Doctors study, which followed up 34,439 male British doctors from 1951 to 2001, and the Million Women Study, which followed 1,3 million women in the UK from 1996–2001 until 2011. After adjusting for confounding factors like socioeconomic status, these studies found that for smokers who did not stop, the average loss of life expectancy was 10 years for men and 11 years for women. Based on average cigarettes smoked per day, this translates to 17 minutes per cigarette for men and 22 minutes per cigarette for women – significantly higher than the previous estimate.

The implications:

Putting a number on the life expectancy cost on each individual cigarette can be a useful motivational aid for quitting. It’s also worth noting that studies generally suggest smoking shortens health expectancy and life expectancy by a similar amount, so each cigarette also brings disease and disability about 20 minutes closer. However, it’s important to keep in mind that all these figures are averages, and assume that each individual cigarette reduces life expectancy by the same amount. This does not appear to be the case, at least at higher levels of consumption. For example, smoking 40 cigarettes a day does not appear to be twice as bad as smoking 20, though this may be because people smoking 40 cigarettes a day smoke them faster and so inhale less smoke. Some cigarettes may be more harmful than others (though they are all still all extremely bad) and different people and age groups may also be affected differently.

One last and more upbeat caveat is that these figures are for smokers who never stopped smoking. However, research suggests that people who quit smoking (and especially those who do so before middle age) actually regain most of their lost life expectancy (in addition to not losing even more life expectancy due to continued smoking). In other words, those 17-22 minutes you lose for each cigarette are not lost permanently, and can be largely recouped if you are able to quit.