The International Scientific Forum on Alcohol Research released its first critique of 2014 today

The International Scientific Forum on Alcohol Research released its first critique of 2014 today

A large group of investigators participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study have reported on the association of alcohol consumption with disease-specific mortality over a 12-year period among a very large number of men and women.

Alcohol intake over the past year (as well as estimates of earlier intake) was reported at baseline. A variety of approaches were used to identify deaths in the participating cohorts, but validation of the cause of death was not possible. No data was reported on certain key aspects of drinking pattern (frequency of alcohol intake, binge drinking, with meals, etc.) and beverage-specific effects were not reported. 

The authors report that the risk of death from cardiovascular diseases was lower, and from cancer and certain other causes of death were higher, among drinkers than among their referent group of “lifetime light users” (men reporting less than 1 drink per week and women reporting less than 0.5 drinks per week).

However, their graphs of alcohol intake and risk of total mortality show strong J-shaped curves for increasing alcohol intake for both men and women. For men, the risk among alcohol consumers of up to about 48 gr/day (the equivalent of approximately four “typical drinks”) was lower than that of the lifetime light users that made up the referent group; at higher intake, the risk increased above that of light drinkers.

For women, the risk of total mortality for drinkers remained lower than that of the referent group at all reported levels of intake. Despite these findings, the entire paper focuses only on the increased risk of death from alcohol for certain diseases, and almost completely ignores the net, overall effects on total mortality.

Forum reviewers considered that, while the analyses were done correctly, there were major weaknesses in the estimation of “lifetime alcohol intake”, no data on the pattern of intake, no validation of coexisting diseases and, especially, no validation of the specific cause of death, even though this was the primary outcome of the study.

All of these factors weaken the strong assertions made by the authors in their conclusions. 

Forum members were concerned that the authors seemed to obscure the total effects of light-to-moderate drinking (lower risk of all-cause mortality), and emphasise only the harmful effects. 

It is interesting that two commentaries published with this article came to divergent views. One by Stockwell and Chikritzhs emphasised potential bias and confounding that cause concern when relating alcohol to mortality in observational studies. While they then pointed out how well the present authors adjusted for many of these factors, they nevertheless concluded their commentary repeating how such factors are difficult to control and stating that “... a healthy dose of scepticism is warranted for the hypothesis that light/moderate alcohol consumption is beneficial to health.” 

On the other hand, the commentary on the present paper by Banks considered the data presented quite sound, and concluded: “If taken as causal, these findings are consistent with most public health advice about alcohol, except that most advice recommends an upper limit to alcohol consumption, but does not actually encourage drinking. In fact, the evidence goes further than this and indicates that, in later life, on average and bearing in mind the priorities and risks of specific individuals, drinking at least some alcohol, but not too much, is likely to minimise the overall risk of death.” 

To read the full critique, click here.

These critiques are published with the permission of The ISFAR.