Each cigarette shortens life by 20 minutes

[Kyng]

https://www.theguardian.com/society/2024...ancy-study

Smokers are being urged to kick the habit for 2025 after a fresh assessment of the harms of cigarettes found they shorten life expectancy even more than doctors thought.

Researchers at University College London found that on average a single cigarette takes about 20 minutes off a person’s life, meaning that a typical pack of 20 cigarettes can shorten a person’s life by nearly seven hours.

According to the analysis, if a smoker on 10 cigarettes a day quits on 1 January, they could prevent the loss of a full day of life by 8 January. They could boost their life expectancy by a week if they quit until 5 February and a whole month if they stop until 5 August. By the end of the year, they could have avoided losing 50 days of life, the assessment found.

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Yeah, this is more than was previously thought. I remember reading in a school textbook that each cigarette shortens a person's life by around 14 minutes!

Just makes me glad I've never smoked in my life (and never plan to...)

[Bryn]

You know, this would make a brilliant PSA idea, as to really drill it into people's heads...

[slooroo]

My friend's mother was a chain smoker and she died a very gruesome death from lung cancer. I wasn't interested in smoking even before that but after definitely not. That said sharing smoking facts has helped lower smoking rates some but it'll never be zero.

[~ True Legend ~]

1) Not sure how this type of thing can be measured. We can’t go back in time and rewrite history for the same person who smoked x number of cigarettes to smoke y number of cigarettes instead. So how can the measure be objective?

2) We don’t know whether this negative correlation between number of cigarettes and life expectancy is linear or expectancy. 

3) We can’t establish cause and effect - it’s possible that those who smoke most are more likely to have depression or other unhealthy lifestyle habits. And the decrease in life expectancy may be due to that rather than smoking.

[Cory]

I never realized smoking had that bad of an effect on your health. I had a friend in high school who smoked cigarettes and weed, I think he once offered me a smoke, and his friend did too. I refused and I've never taken a puff in my life even though I've been around a handful of people who have. Suffice it to say, physically speaking I've always been pretty healthy according to my doctors.

[Kyng]

1) Not sure how this type of thing can be measured. We can’t go back in time and rewrite history for the same person who smoked x number of cigarettes to smoke y number of cigarettes instead. So how can the measure be objective?

2) We don’t know whether this negative correlation between number of cigarettes and life expectancy is linear or expectancy. 

3) We can’t establish cause and effect - it’s possible that those who smoke most are more likely to have depression or other unhealthy lifestyle habits. And the decrease in life expectancy may be due to that rather than smoking.

#1: Well, we can measure the average lifespans of smokers vs. non-smokers. Then, we can get an idea of how many cigarettes a typical smoker smokes in their lifetime - and divide the shortening in lifespan by the total number of cigarettes smoked. (For example: if smokers lived 1 year less on average than non-smokers, and smoked 25,000 cigarettes on average over the course of their lifetime... then, we could say that each cigarette, on average, shortened their life by 1/25,000 years - which works out to roughly 20 minutes).

#2: Yeah, that's a good point: it could be that the first few cigarettes are the most harmful, or that the first few are pretty harmless and then they get increasingly harmful over time.

#3: Yes, we can - and we have. The causal link between smoking and cancer (and other health problems) is already very well-established by prior research. Now that its existence has been established, this study merely seeks to quantify it.