Is alcohol beneficial in small amounts?

Question

It's widely believed that consuming small amounts of alcohol has many health benefits.

As a matter of fact, a lot of alcohol might be good for you, as Wired Magazine reports:

It’s one of those medical anomalies that nobody can really explain: Longitudinal studies have consistently shown that people who don’t consume any alcohol at all tend to die before people who do.

Well, the anomaly has just gotten more anomalous: A new study, published in the journal Alcoholism: Clinical and Experimental Research, followed 1,824 participants between the ages of 55 and 65. Once again, the researchers found that abstaining from alcohol increases the risk of dying, even when you exclude former alcoholics who have now quit. (The thinking is that ex-drinkers might distort the data, since they’ve already pickled their organs.) While 69 percent of the abstainers died during the 20-year time span of the study, only 41 percent of moderate drinkers passed away. (Moderate drinkers were also 23 percent less likely to die than light drinkers.) But here’s the really weird data point: Heavy drinkers also live longer than abstainers. (Only 61 percent of heavy drinkers died during the study.) In other words, consuming disturbingly large amounts of alcohol seems to be better than drinking none at all.

Is this true? Is there any conflicting evidence? If it is true, is there any indication as to what it does that might cause these beneficial effects?

Answer 1

It seems to depend on the way the observational, epidemiological and correlational data is used. That is: how the data is gathered, analysed and interpreted. And how puritan the belief systems of the researchers are.

Drinking large amounts of alcohol is bad. Doing that daily is bad. A recent study amassed a huge dataset and concluded that the only safe amount of alcohol is zero. This got even published ion The Lancet as

"Alcohol use and burden for 195 countries and territories, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016"

The key findings are communicated in the extreme, globally, and badly:

Analysing data from 15 to 95-year-olds, the researchers compared people who did not drink at all with those who had one alcoholic drink a day.
They found that out of 100,000 non-drinkers, 914 would develop an alcohol-related health problem such as cancer or suffer an injury.
But an extra four people would be affected if they drank one alcoholic drink a day.
For people who had two alcoholic drinks a day, 63 more developed a condition within a year and for those who consumed five drinks every day, there was an increase of 338 people, who developed a health problem.

That is from a baseline of 914 problems in 100000 people an increase to 918 people in 100000 for one drink a day. As one can see, problems usually related to alcohol develop in 914 non-drinkers already or as well and one drink a day means trouble for an additional 4 people.

Is much or not? If that is difficult to picture mentally, The Lancet provides you the service of a picture that gets overlooked in the sensationalist press:

The relative risk increase in a study that claims zero is the only safe level for one drink per day is effectively zero as well.

This study aims at scare mongering and has to admit that

Alcohol use is a leading risk factor for death and disability, but its overall association with health remains complex given the possible protective effects of moderate alcohol consumption on some conditions.

This study still does not challenge "moderate alcohol consumption may be preventive for some conditions such as ischaemic heart disease and diabetes" but looks at the effects associated with each individual health outcome together with level of alcohol consumption. When those inferences are then combined into an aggregate according to the author's model we arrive at the picture above.

Specifically, comparing no drinks with one drink a day the risk of developing one of the 23 alcohol-related health problems was 0.5% higher — meaning 914 in 100,000 15–95 year olds would develop a condition in one year if they did not drink, but 918 people in 100,000 who drank one alcoholic drink a day would develop an alcohol-related health problem in a year.

This increased to 7% in people who drank two drinks a day (for one year, 977 people in 100,000 who drank two alcoholic drinks a day would develop an alcohol-related health problem) and 37% in people who drank five drinks every day (for one year, 1252 people in 100,000 who drank five alcoholic drinks a day would develop an alcohol-related health problem).

How do experts judge this data?

David Spiegelhalter, Winton Professor for the Public Understanding of Risk at the University of Cambridge, said:

“According to data provided by the authors but not published in the paper, to suffer one extra alcohol-related health problem, around 1,600 people would need to drink two drinks totalling 20g (2.5 units) of alcohol a day for a year. This is equivalent to around 32 standard 70cl bottles of gin over a year, so a total of 50,000 bottles of gin among these 1,600 people is associated with one extra health problem. This indicates a very low level of harm in moderate drinkers, and suggests UK guidelines of an average of 16g a day (2 units) are very low-risk indeed.

“Given the pleasure presumably associated with moderate drinking, claiming there is no ‘safe’ level does not seem an argument for abstention. There is no safe level of driving, but government do not recommend that people avoid driving. Come to think of it, there is no safe level of living, but nobody would recommend abstention.”

This same year another Lancet paper tried to tackle the problem:

Angela M Wood et al.: "Risk thresholds for alcohol consumption: combined analysis of individual-participant data for 599 912 current drinkers in 83 prospective studies", Volume 391, Issue 10129, p1513-1523, April 14, 2018
Low-risk limits recommended for alcohol consumption vary substantially across different national guidelines. To define thresholds associated with lowest risk for all-cause mortality and cardiovascular disease, we studied individual-participant data from 599 912 current drinkers without previous cardiovascular disease.
In current drinkers of alcohol in high-income countries, the threshold for lowest risk of all-cause mortality was about 100 g/week. For cardiovascular disease subtypes other than myocardial infarction, there were no clear risk thresholds below which lower alcohol consumption stopped being associated with lower disease risk. These data support limits for alcohol consumption that are lower than those recommended in most current guidelines.

Again, a call "to lower guidelines". Despite the result that for some outcomes the lowest risk was not "zero drinks" but that the relative risk increases, clearly, if you go below 100g of pure alcohol a week!

From the supplementary material: (click to enlarge)

Do these numbers really suggest that not drinking alcohol – either never or even worse to quit drining – is to be seen as a potential risk factor? The huge difference between never-drinkers and ex-drinkers might spoil that party a bit. An equally plausible explanation for that is that dislike for alcohol might be a sign for already frail or future health problems.

Summary

The vast majority of findings show that moderate drinking (definitions of that may vary as much as does individual tolerance) carries a low risk and that there is an ultimately unexplained correlation between drinking a bit and slightly longer life expectancy. The French Paradox keeps on giving.

Answer 2

The study is from a reputable scientific journal, and appears to apply good scientific methods and to exclude (as far as possible) a large number of alternative factors that might have caused the difference in mortality. Also this is far from the only study to have found that moderate alcohol consumption correlates with better health and longer life. Most studies report probable health benefits, but stop short of stating a provable connection.

Here is a report which lists five scholarly scientific studies showing the correlation. Here is a Mayo Clinic study.

Moderate alcohol consumption may provide some health benefits. It may: Reduce your risk of developing heart disease; Reduce your risk of dying of a heart attack; Possibly reduce your risk of strokes, particularly ischemic strokes; Lower your risk of gallstones; Possibly reduce your risk of diabetes. Even so, the evidence about the possible health benefits of alcohol isn't certain, and alcohol may not benefit everyone who drinks.

Here is one from the National Institute on Alcohol Abuse and Alcoholism (which also lists some of the downsides).

In the past two decades, however, a growing number of epidemiologic studies have documented an association between alcohol consumption and lower risk for coronary heart disease (CHD), the leading cause of death in many developed countries (Chadwick and Goode 1998; Criqui 1996a,b; Zakhari 1997). Much remains to be learned about this association, the extent to which it is due specifically to alcohol and not to other associated lifestyle factors, and what the biological mechanisms of such an effect might be

Here is the US dietary guidelines, alcohol section.

Heavy drinking increases the risk of liver cirrhosis, hypertension, cancers of the upper gastrointestinal tract, injury, and violence (USDA, 2000). A recent analysis of the preventable causes of mortality in the United States (US) attributed 90,000 deaths a year to alcohol misuse (Danaei, 2009). However, the health consequences of consuming lesser amounts of alcohol are also important because of the large percent of the population that consumes alcohol at or below government recommendations on limits for intake. It is estimated that 26,000 fewer deaths were averted due to reductions in heart disease, stroke and diabetes from the benefits attributed to moderate alcohol consumption.

Drinking moderate amounts of alcohol will impair your judgement, possibly causing you to drink more alcohol than you intended. The risks of alcoholism and vehicle accident are well known - I guess they could be considered counter-evidence. There are also studies that have shown increases in cancer related to alcohol consumption, as answered in this question. The more general studies would tend to indicate that the positive benefits outweigh the negative. This is not a clear-cut situation.

Answer 3

Here is study from 2008 that suggests drinking red wine can decrease the risk of lung cancer in men. Lung cancer is the leading cause of cancer death in both men and women in the United States.

The California Men's Health Study is a multiethnic cohort of 84,170 men ages 45 to 69 years [...] examine the effects of beer, red wine, white wine (including rosé), and liquor consumption on risk of lung cancer adjusting for age, race/ethnicity, education, income, body mass index, history of chronic obstructive pulmonary disease/emphysema, and smoking history.

...

Alcohol consumption has been shown to increase risk for several cancers, including cancers of the head and neck, esophagus, liver, colon, rectum, and female breast. [...] The effect of alcohol use on lung cancer, however, has been controversial.

...

We did not find any clear association between lung cancer risk and consumption of beer, white wine, or liquor after adjusting for demographics and lifestyle factors including smoking history, socioeconomic status, BMI, and history of COPD/emphysema. However, an inverse association for red wine use was consistently observed, particularly among ever-smokers (=people who have smoked at least 100 cigarettes in their life). [...] Among ever-smokers, consumption of at least 1 drink of red wine per day was associated with an approximately 60% reduced risk of lung cancer

...

Although we cannot completely exclude the possibility of residual confounding, the lack of association for white wine lends support to a causal association for red wine and suggests that compounds that are present at high concentrations in red wine but not in white wine, beer, or liquors may be protective against lung carcinogenesis.

But Chun Chao, lead author of the study, warns:

We need more studies on whether people should drink red wine to reduce lung cancer risk. If people want to drink red wine for cardiovascular benefits, they should talk to their doctor about that. But they shouldn't drink for lung cancer prevention.

And the Nationale Cancer Institute's stance:

Some studies suggest that alcohol consumption is associated with a lower risk of some non-cancer health conditions. However, it is not recommended that anyone begin drinking or drink more frequently on the basis of health considerations.

Answer 4

I've found a document with lots of references called, The Effects of Moderate Beer Consumption.

It contains this chart, that shows drinking 4 drinks a day for a man has the same relative risk of mortality as drinking none.

From Di Castelnuovo A, Costanzo S, Bagnardi V et al. (2006). “Alcohol dosing and total mortality in men and women: An updated meta-analysis of 34 prospective studies”. Archives of Internal Medicine, 166:2437-2445.

Edit:

From Sheffield Addiction Research Group, on a UK Parliamentary website, about the evidence that the chart presents:

Studies of the relationship between alcohol and harm are frequently subjected to systematic reviews in order to identify those studies of the highest quality and to aggregate the effects into a more robust overall estimate of the relationship. Systematic reviews are carried out on a regular basis for individual harms and for all-cause mortality. This evidence is also compiled in the WHO's work on the burden of total disease which is due to alcohol. Therefore, the evidence on which guidelines are based can be considered as of the highest quality available and is reviewed and updated on a regular basis.

In addition:

Many studies of the risk of alcohol consumption are based on survey data which ask respondents to report their consumption. Such reports are known to substantially underestimate the amount of alcohol believed to be consumed based on sales data, by between 40% and 60%. Although efforts have been made to explain and address this problem, many estimates of the risk from alcohol consumption may be biased upwards by under-reporting of heavy consumption.

Answer 5

I've written about this for years.

A new CU analysis slices non-drinkers-now by past-heavy-drinking vs. not, and finds that the never-heavy-drinking non-drinkers are equally healthy to light-drinkers-now. This doesn't exactly seem fair given that they don't slice light-drinkers-now in the same way (so they don't really prove absence of benefit from light drinking), but I think that coupled with the lack of a plausible mechanism (hormesis? feeling less stressed or more rewarded by social encounters while buzzed?), you may as well act as though being the least drunk you can get away with, socially, is the healthiest choice.

It's easy to imagine plausible factors that "explain away" the advantage of light/moderate drinkers over non; it's nice that these Colorado U. folks found one that could be tested against existing survey data. Some others: sick people tend to stop drinking alcohol (medication interactions, or just wanting to sleep well and avoiding painful hangovers), people who are more social and active tend to drink w/ friends (people who have good encounters with friends are healthier, causality probably in both directions), extremely poor people may avoid alcohol in favor of necessities, etc.

Answer 6

I usually like to give more than a quote, but in this case, the following quote says it all:

• No alcohol safe to drink, global study confirms - BBC

The Global Burden of Disease study [published in the Lancet] looked at levels of alcohol use and its health effects in 195 countries, including the UK, between 1990 and 2016.

Analysing data from 15 to 95-year-olds, the researchers compared people who did not drink at all with those who had one alcoholic drink a day.

They found that out of 100,000 non-drinkers, 914 would develop an alcohol-related health problem such as cancer or suffer an injury.

But an extra four people would be affected if they drank one alcoholic drink a day.

For people who had two alcoholic drinks a day, 63 more developed a condition within a year and for those who consumed five drinks every day, there was an increase of 338 people, who developed a health problem.