All the time I see content online that says moderate alcohol consumption is good for you. Some even say it is better than no alcohol consumption. Other times there is conflicting information that says no alcohol consumption is better. I'm assuming there just isn't a consensus on it but, as a person who doesn't drink alcohol, I'm curious how drinking moderately could improve my health.
While there is some evidence for what we call a J-shaped curve in the relationship between alcohol consumption and certain health outcomes, at best this evidence only suggests people who already drink modestly have better health outcomes than people who don't drink at all. There is no strong evidence that starting to drink a glass a day, if you do not drink already, would improve your health outcomes. There is an important point here about study design. Evidence for the J-shaped curve is generally observational, often retrospective, and can only tell you about an association between some variable and a disease outcome. It may be an important association, e.g., a valuable marker for risk of disease, but it doesn't tell you what happens if you change the variable. To know what happens when you change the variable, you typically want a randomized controlled trial.
Abstaining from alcohol (vs. moderate consumption) is likely what we call a confounding variable. It is associated with the variable of interest (some health outcome, e.g., mortality), but it is not on the causal pathway. That is to say, people who don't drink at all may be more likely to be ill (or become ill), but they didn't get that way because they don't drink. This is well explored in this meta analysis. A key part here is that former drinkers who currently don't drink any alcohol appear to be the major driver of the higher risk of mortality for individuals who don't drink at all. This suggests earlier heavy drinking or illness that causes someone to stop drinking.
The reason you may want to be a moderate drinker is they're found to have lesser rates of death from heart disease and diabetes, which are dominant causes of death in a developed society.
This is one study I'll be referring to, as it got a lot of press last summer,
- Alcohol use and burden for 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016
Below, if you’re above 1, that means you have greater risk of heart disease. Below 1, lesser risk. Drinkers have less risk, until they get to 6 (!) drinks per day.
Heart disease deaths, up to a point, go down as people drink more. (Specific chart is for females but same trend happens for males; bottom ticks each represent one standard drink per day.)
Note, you need to live long enough for heart disease or diabetes to potentially kill you in order to get this benefit. If you're in a low income country, alcohol only increases your risk of death:
If you're in a rich country though, you get a lot of benefit from drinking alcohol, practically completely offsetting that initial negative we saw:
If you examine the causes of death above more closely, you'll see ones like violence, cirrhosis, self-harm, etc. One could make an argument these don't apply to our moderate drinker, to where you could get rid of some of those deaths. That is, you're getting less negative and more positive.
Pinning down to specific people
The natural next question is some variety of "why?"
People pretty much always go digging for biochemical answers, but as a personal trainer who has talked to many different personalities about alcohol through the years, a (I believe) very under appreciated element of alcohol is the kind of personality who swears it off.
For instance, on one extreme, you have the person who is an alcoholic. Any alcohol turns into way too much. Obviously not healthy.
You also have the person who is trying to be too strict about everything in their lives. Where they're inherently neurotic. Not a recipe for longterm health.
There is research showing drinkers weigh less than non-drinkers. Personally, I've found with my clients some of them, if they have a drink after a rough day, that's the end of it. While others, if they don't drink, might eat a tub of ice cream. I've also seen other trainers / nutritionists tell their clients they can't drink at all anymore, only for the clients to be miserable. "Going to my weekly date night with my spouse isn't as enjoyable."
Alcohol can mean a lot to a lot of people's social lives. If swearing it off ends up making you more lonely or isolated, that's not good for the heart. (Seriously. There is literature out there talking about the dangers of loneliness.)
With virtually any health question or topic, you're going to be hard pressed to acceptably paint a brush to how people should behave. (No smoking is probably the only one.) If you have a family history of breast cancer maybe you shouldn't drink; if you have one of thyroid, maybe you should?