Critique 135: Binge drinking greatly increases mortality risk among moderate drinkers — 11 March 2014

Holahan CJ, Schutte KK, Brennan PL, Holahan CK, Moos RH.  Episodic heavy drinking and 20-year total mortality among late-life moderate drinkers.  Alcohol Clin Exp Res 2014; pre-publication; DOI: 10.1111/acer.12381.

Authors’ Abstract

Background: Analyses of moderate drinking have focused overwhelmingly on average consumption, which masks diverse underlying drinking patterns.  This study examined the association between episodic heavy drinking and total mortality among moderate-drinking older adults.

Methods: At baseline, the sample was comprised of 446 adults aged 55 to 65; 74 moderate drinkers who engaged in episodic heavy drinking and 372 regular moderate drinkers. The database at baseline also included a broad set of sociodemographic, behavioral, and health status covariates. Death across a 20-year follow-up period was confirmed primarily by death certificate.

Results: In multiple logistic regression analyses, after adjusting for all covariates, as well as overall alcohol consumption, moderate drinkers who engaged in episodic heavy drinking had more than 2 times higher odds of 20-year mortality in comparison with regular moderate drinkers.

Conclusions: Among older moderate drinkers, those who engage in episodic heavy drinking show significantly increased total mortality risk compared to regular moderate drinkers. Episodic heavy drinking—even when average consumption remains moderate—is a significant public health concern.

Forum Comments

Background:  For several decades, epidemiologists have realized that the pattern of drinking — regular versus episodic — is a strong determinant of whether alcohol consumption has net risks or benefits regarding health and mortality.  For example, two studies from Finland have shown adverse health effects of alcohol among subjects who binge drink, in comparison with drinkers who do not binge.(1,2)  In 2005, Mukamal et al(3) showed that, among subjects interviewed within days after having a myocardial infarction, those reporting drinking without binges (n=766) over the preceding year had lower mortality than those reporting binge drinking (n=250), as well as a lower mortality risk than abstainers (n=903).  These authors defined binge drinkers as those who reported consuming 3 drinks or more within 1 to 2 hours.  They concluded: “Binge drinkers had a 2-fold higher risk of mortality than drinkers who did not binge (hazard ratio, 2.0; 95% confidence interval, 1.3 to 3.0).”

In 2007, Rehm et al(4) presented estimates of risks and benefits associated with “moderate” consumption of alcohol in terms of mortality for Canada in 2002 by age and sex.   Moderate was initially defined simply as an average intake of < 20 g/day for women and < 40 g/day for men; with this definition, there were greater numbers of deaths attributed to alcohol than “prevented” by alcohol, especially from young subjects dying from accidental causes.  When the definition of “moderate” included only subjects who did not report binge drinking, the net effects on mortality were strongly protective.  These authors concluded: “Overall, the net impact of on-average moderate alcohol consumption on mortality depends on patterns of drinking.”    

Ruidaverts et al(5) reported on the risk of myocardial infarction in almost 10,000 subjects in Northern Ireland and France in the PRIME study.  They found that “Regular and moderate alcohol intake throughout the week, the typical pattern in middle aged men in France, is associated with a low risk of ischaemic heart disease, whereas the binge drinking pattern more prevalent in Belfast confers a higher risk.”  Their data showed that the hazard ratio for hard coronary events for binge drinkers was 1.97 (95% CI 1.21, 3,22) when compared with regular drinkers.  A recent paper by Naimi et al(6) also showed that more frequent drinkers are less likely to be binge drinkers than are infrequent drinkers.

The authors did not comment on the report of follow up of a Danish population of 26,786 men and women who participated in the Danish National Cohort Study in 1994, 2000, and 2005.  Among the moderate drinkers (defined as an average of ≤ 21 and ≤ 14 drinks/week for men and women, respectively) in that study, occasional binge drinking was not associated with an increased risk of ischemic heart disease or all-cause mortality when compared with moderate drinkers who did not binge drink. (7)

Comments on the present study:  In this study, moderate drinkers were defined as those consuming an average of at least one-half drink/day.  For the upper limits of moderate in this study, women were included if they reported consuming “no more than ½ drink/d” and for men, those consuming no more than 2 drinks/d.”  Subjects reporting no alcohol intake or an average of < ½ drink per day were excluded (so the present analyses do not compare mortality between drinkers and abstainers).  Binge drinkers were defined as those reporting 4 or more drinks/occasion for women and 5 or more drinks/occasion for men.  Subjects were classified according to their alcohol intake and drinking pattern only at baseline, and then observed for mortality over the next 20 years.

Forum members noted that the present study was based on a small number of subjects (only 74 binge drinkers).  Reviewer Skovenborg points out a number of other weaknesses: “It has no data on potential changes in alcohol consumption over 20 years; has evidence suggesting selection bias (e.g., from excluding many subjects who were very light drinkers, etc.); the authors do not give confidence intervals for their estimates; there is insufficient adjustment for covariates: (e.g., smoking not classified by amount or duration; there was a very poor measurement of physical activity); and subjects reporting episodic heavy drinkers, who represented the main outcome of the analyses, were 3 times more likely to be problem drinkers at baseline.  All of these factors indicate that there is surely room for residual confounding.” 

Skovenborg added: “This paper confirms a large body of evidence on the harmful effects of binge-drinking and extends the evidence to include late-life moderate drinkers.  There is no doubt that irregular heavy drinking is very harmful and dangerous; the problem is how to categorize irregular heavy drinking.  In the present analyses, eligible participants were subjects who, on average, consumed no more than 3.5 drinks/week for women and 14 drinks/week for men.  However, some of the moderate drinkers acknowledged previous heavy drinking episodes, which makes the current results difficult to interpret.”  Further, subjects in one of the two cohorts upon which the analyses were carried out were chosen because they had “current or past drinking problems,” so this is not a population-based analysis.  Nevertheless, the analyses in the present paper support findings from much previous research indicating that “moderate” drinkers who binge drink may have higher mortality risk than such drinkers who do not engage in episodic heavy drinking. 

Among comments from other Forum members were the following: reviewer Finkel raises a question: “Might those who drove home after binge drinking contribute to the differences in mortality?”  Forum member Ursini reminded us that the results of this paper simply reinforce a very old message: “During meals drink wine happily, little but often . . . to avoid harming the body never drink between meals,” from Arnoldo da Villanova (1253-1315), from the Regimen Sanitatis Salernitani, a manuscript from the Schola Medica Salernitana, the world’s first medical school that was prominent in the 10-13th centuries.  The school was situated on the Tyrrhenian Sea in the south Italian city of Salerno, and was the most important source of medical knowledge in Western Europe at the time.

References for this critique:

  1. Kauhanen J, Kaplan GA, Goldberg DE, Salonen JT.  Beer binging and mortality: results from the Kuopio ischaemic heart disease risk factor study, a prospective population based study. BMJ 1997;l315:846–851.
  2. Laatikainen T, Manninen L, Poikolainen K, Vartiainen E.  Increased mortality related to heavy alcohol intake pattern. J Epidemiol Community Health 2003;57:379–384.
  3. Mukamal KJ, MaclureM, Muller JE, MittlemanMA.  Binge drinking and mortality after acute myocardial infarction. Circulation 2005;112:3839–3845.
  4. Rehm J, Patra J, Taylor B.  Harm, benefits, and net effects on mortality of moderate drinking of alcohol among adults in Canada in 2000. Ann Epidemiol 2007;17(Suppl):S81-S86.
  5. Ruidaverts J, Ducimetiere P, Evans A, et al.  Patterns of alcohol consumption and ischaemic heart disease in culturally divergent countries: the Prospective Epidemiological Study of Myocardial Infarction (PRIME). BMJ 2010;341:c6077.;doi:10.1136/bmj.c6077.
  6. Naimi TS, Xuan Z, Brown DW, Saitz R.  Confounding and studies of ‘moderate’ alcohol consumption: the case of drinking frequency and implications for low-risk drinking guidelines. Addiction 2013;108:1534–1543.
  7. Skov-Ettrup LS, Eliasen M, Ekholm O, Grønbaek M, Tolstrup JS.  Binge drinking, drinking frequency, and risk of ischaemic heart disease: A population-based cohort study.  Scandinavian Journal of Public Health 2011;39:880–887.

Forum Summary

This study was based on a sample of “late-middle-aged community residents” (55–65 years old at baseline) who were recruited from the western part of the United States to participate in a study of late-life alcohol consumption and drinking problems.  The present analyses evaluated   association between episodic heavy drinking and total mortality among 446 adults who were considered to be “moderate” drinkers.  The authors report that the 74 moderate drinkers who engaged in episodic heavy drinking (“binge drinking”) had more than two times higher odds of 20-year mortality than moderate drinkers who did not binge drink.

An association between binge drinking and health outcomes has been demonstrated in epidemiologic studies for decades.  Many (but not all) studies have shown an approximately two-fold increase in the risk of adverse outcomes for binge drinkers, in comparison with moderate drinkers who do not binge drink.  In reviewing the present study, Forum members commented on the small number of subjects (only 74 binge drinkers in the analysis), and some other analytic weaknesses (e.g., no data on potential changes in drinking habits over 20 years, inadequate control of some potential confounders, results not applicable to the general population as some subjects were recruited because of previous alcohol misuse).  Nevertheless, the results of the study support adverse effects on mortality of such a drinking pattern.

There are now considerable scientific data indicating harmful health effects of episodic excessive drinking in terms of coronary heart disease, other diseases of ageing, and mortality.  Simply knowing the average intake of subjects over a period of time is inadequate for classifying their alcohol consumption.  For middle-aged and older subjects the drinking pattern that has been shown to be associated with the most favorable health outcomes (including greater longevity of life) is regular, light-to-moderate intake, especially when the alcoholic beverage is consumed with food.   

                                                              *                      *                      *

Comments on this critique were provided by the following members of the International Scientific Forum on Alcohol Research:

Harvey Finkel, MD, Hematology/Oncology, Boston University Medical Center, Boston, MA, USA

Erik Skovenborg, MD, Scandinavian Medical Alcohol Board, Practitioner, Aarhus, Denmark

Creina Stockley, MSc, MBA, Clinical Pharmacology, Health and Regulatory Information Manager, Australian Wine Research Institute, Glen Osmond, South Australia, Australia

Arne Svilaas, MD, PhD, general practice and lipidology, Oslo University Hospital, Oslo, Norway

Dominique Lanzmann-Petithory,MD, PhD, Nutrition/Cardiology, Praticien Hospitalier Hôpital Emile Roux, Paris, France

Fulvio Ursini, MD, Dept. of Biological Chemistry, University of Padova, Padova, Italy

Andrew L. Waterhouse, PhD, Marvin Sands Professor, Department of Viticulture and Enology, University of California, Davis; Davis, CA, USA

R. Curtis Ellison, MD, Section of Preventive Medicine & Epidemiology, Boston University School of Medicine, Boston, MA, USA

Pierre-Louis Teissedre, PhD, Faculty of Oenology – ISVV, University Victor Segalen Bordeaux 2, Bordeaux, France

David Van Velden, MD, Dept. of Pathology, Stellenbosch University, Stellenbosch, South Africa