The standard response to that is 0 drinks per day includes abstainers who might be former alcoholics and therefore might be dragging the average down. Some of the data tables have a separate category for "excluding abstainers", but there's no line graph that has abstainers excluded.
Doesn't sound like they controlled for it or even considered it. While they did have a control group that excluded non-drinkers and heavy drinkers, that was solely to control for bias at the extreme ends, and not to control for sober alcoholics or health problems that preclude drinking.
> Our analyses comprise models that include two different sets of control variables. The standard set includes standardized age, standardized age squared standardized height, handedness (right/left/ambidextrous; dummy-coded), sex (female:0, male:1), current smoker status, former light smoker, former heavy smoker, and standardized Townsend index of social deprivation measured at the zip code level62. To control for genetic population structure, the models also include the first 40 genetic principal components63 and county of residence (dummy-coded)62. A second set of extended control variables includes all standard control variables and in addition standardized BMI, standardized educational attainment64, and standardized weight. To determine whether observations at the extreme ends of the drinking distribution bias the estimates of the relationship between alcohol intake and IDPs, we also estimate a model that excludes abstainers and a model that excludes heavy drinkers (i.e., women who reported consuming more than 18 units/week and men who consumed more than 24 units/week), both with standard controls.
Here they talk about the different groupings:
> we bin participants in the following six categories based on average alcohol intake: (1) abstainers, (2) individuals who drank less than one unit/day, (3) individuals who drank between one (included) and two (excluded) units/day (recommended maximal alcohol consumption based on the UK Chief Medical Officers “low-risk” guidelines32), (4) individuals who drank between two (included) and three (excluded) units/day, (5) individuals who drank between three (included) and four (excluded) units/day, and (6) individuals who drank at least four units/day.
Again no mention of sober alcoholics or health problems.
This study: https://www.massgeneral.org/news/press-release/large-study-c... found that while moderate drinkers had better cardiovascular health than non-drinkers, this was due to other lifestyle factors associated with moderate drinking, not the drinking itself.
There are way fewer alcoholics than any other category so even if you factor in sober alcoholics you are dominated by people who drank less and now abstain or have never drunk.
