The problem with these studies is they do not account for other factors.
Basically, it says that drinking a glass of wine is good for you. While drinking straight alcohol, beer or cider is not.
Does it also account for the BMI of the beer or cider or spirits drinkers?
Maybe people who drink only small amounts of wine are also more health conscience in general. They get more exercise. They eat better food. They watch what they eat.
All excessive alcohol consumption is generally bad for you.
I personally also find it leads to eating bad food or over eating. Meaning, if you are hung over you tend to eat crap food to make your stomach feel better.
Typically the ONLY cure is to have another drink. So, it becomes a spiral trap/addiction.
Sounds like it.