I think you misunderstand op's point.

It's like saying the interesting part of the study is "why people who die younger choose to smoke" about a study correlating early death with smoking.

The point being there is no such choice being made.

Pretty much all sport clubs I have been at when younger drunk a lot. The socializing after sport often involves a lot of alcohol. Includes underage clubs.

Don’t they just both correlate with socio economic status?

Can’t read actual methods to check if this was adjusted for…