I think parent comment was pointing to lack of establishing a causation link. The finding in their abstract is extrapolated by statistical inference. For exampl

I think parent comment was pointing to lack of establishing a causation link. The finding in their abstract is extrapolated by statistical inference. For example smokers tend to drink more etc. The paper does take such factors into account. Personally I wouldn't jump to such a strong conclusion from statistical inference because it closes the door on other factors that might be even stronger when combined together. The paper reflects motivated reasoning more than a discovery outcome. That said, smoking is of course a major health risk, I am just pointing at the research approach.