• Heavier smoking increases coffee consumption: findings from a Mendelian randomization analysis 

      Bjørngaard, Johan Håkon; Nordestgaard, AT; Taylor, Amy E; Treur, Jorien L; Gabrielsen, Maiken Elvestad; Munafo, Marcus R; Nordestgaard, BG; Åsvold, Bjørn Olav; Romundstad, Pål Richard; Davey Smith, George (Journal article; Peer reviewed, 2017)
      Background There is evidence for a positive relationship between cigarette and coffee consumption in smokers. Cigarette smoke increases metabolism of caffeine, so this may represent a causal effect of smoking on caffeine ...