Alcohol and tobacco

Alcohol and tobacco are the two most widely used recreational drugs, and both are leading preventable causes of death. Their harms rise with the amount used, and both cause cancer as well as heart, blood vessel and other diseases. Most of the evidence comes from observational studies, which track people's habits and health over time rather than assigning them to drink or smoke.

Alcohol was the seventh leading risk factor for death and disability worldwide in 2016, and the leading one among people aged 15 to 49 [1]. In a pooled analysis of 599,912 current drinkers in 83 studies, the lowest mortality (risk of death) was at or below about 100 g of alcohol a week, and drinking more than 350 g a week was associated with 4 to 5 fewer years of life expectancy at age 40 [2]. The earlier finding that moderate drinkers outlive non-drinkers largely disappears when former drinkers who stopped because of illness are no longer counted as non-drinkers [3]. An estimated 741,300 new cancer cases worldwide in 2020 were attributable to alcohol [4].

Smoking shortens life by about ten years, a figure found both in a survey of more than 200,000 US adults [5] and in 50 years of follow-up of 34,439 British doctors [6]. Even one to ten cigarettes a day throughout life was associated with 87% higher mortality than never smoking [7]. Stopping recovers much of the loss: people who stopped at 25 to 34, 35 to 44 and 45 to 54 gained about 10, 9 and 6 years of life compared with those who continued [5]. The most effective stop-smoking medicines and nicotine e-cigarettes roughly double the odds of stopping for six months or more in randomised trials (studies that assign participants to groups by chance) [8].