Those extra shots of espresso could be a killer for smokers. Drinking two-to-three eight-ounce cups of coffee a day was associated with increasing the risk of lung cancer by more than a third for current and former smokers, according to Buffalo's Roswell Park Cancer Institute in the US.
Being a smoker or ex-smoker and drinking decaffeinated coffee, however, appeared to reduce the risk – as did eating a healthy diet with plenty of fruit and vegetables. It is thought caffeine may counteract the benefits of antioxidants in coffee. So if you're a smoker and love your coffee, switch to decaff.