Early research linked coffee to diseases ranging from heart disease and asthma. But Hu noted that many participants in those studies also smoked, which may have led researchers to think that coffee was responsible for the adverse effects that are now linked with cigarettes. He added that anything people consume a lot of tends to come under scrutiny. “In the past, I think a lot of people thought, ‘Oh, coffee’s so delicious, there must be something bad about coffee,’” he said. “So I think the good news is that [for] most people, coffee actually confers some health benefits.”