|Nutrition Evidence Library|
What is the relationship between alcohol intake and coronary heart disease?
Strong evidence consistently demonstrates that compared to non-drinkers, individuals who drink moderately have lower risk of coronary heart disease (CHD).
Insufficient evidence was available to determine if drinking patterns were predictive of risk of CHD, although there was moderate evidence to suggest that heavy or binge drinking is detrimental.
Grade: Strong; Insufficient
Overall strength of the available supporting evidence: Strong; Moderate; Limited; Expert Opinion Only; Grade not assignable For additional information regarding how to interpret grades, click here.
Evidence Summary Overview
Related to the association between alcohol consumption and risk of coronary heart disease (CHD), six systematic reviews/meta-analyses were reviewed. This evidence included four methodologically strong meta-analyses (Bagnardi, 2008; Corrao, 2000; Di Castelnuovo, 2002; and Rimm, 1999); one methodologically neutral meta-analysis (Cleophas, 1999) and one systematic review that was methodologically neutral (Britton and McKee, 2000).
Overall, the evidence shows that compared to those who abstain from alcohol, regular light to moderate drinking can reduce the risk of CHD; whereas, heavy irregular or binge drinking increases risk of CHD. In a meta-analysis of 20 observational studies, Bagnardi et al, (2008) found significant differences in the alcohol intake dose response relationship to CHD risk in regular vs. irregular drinkers. These authors concluded that the consumption of alcohol on more than two days per week has a significant protective effect against CHD. Cleophas et al, (1999) found that alcohol consumption at one to four drinks per day reduced risk of mortality and CHD, while more than five drinks per day increased risk of mortality, and wine, beer and spirits were equally beneficial. Interestingly, a meta-analysis conducted by Corrao et al, (2000) of 43 cohort studies, found that in Mediterranean countries, protective effects were seen up to 145g per day, but in all other countries, the protective effects were only seen up to 80grams per day. Di Castelnuovo et al, (2000) compared wine and beer consumption in a meta-analysis of 26 international studies. The relative risks of cardiovascular disease (CVD) were 0.68 (95% CI: 0.59-0.77) and 0.78 (95% CI: 0.70-0.86) for consumption of wine and beer, respectively, relative to non-drinkers. Rimm (1999) concluded that based on a meta-analysis of 42 randomized controlled trials (RCTs), alcohol consumption per se, not other components of alcoholic beverages, was responsible for the lower risk of CHD among moderate drinkers. Furthermore, based on measures of high-density lipoprotein cholesterol (HDL-C), triglycerides (TG) and fibrinogen, to the degree documented in the meta-analysis, consumption of two standard drinks per day would lower a person’s risk of CHD by approximately 25%. According to Britton and Mckee (2000) a systematic review of international studies, not only alcohol quantity, but also drinking patterns such as binge drinking, influenced CVD risk.
Collectively, the research suggests that whereas binge drinking (more than three alcoholic drinks every one to two hours) has harmful effects, light to moderate alcohol consumption spread over several days of the week has beneficial effects relative to CVD risk. Therefore, for a given volume of alcohol within a moderate drinking range, it is better to distribute this volume evenly over several days, rather than consuming it in two to three days.
Evidence Summary Paragraphs
Bagnardi et al, 2008 (positive quality) conducted a meta-analysis to evaluate whether drinking pattern, defined by the frequency of drinking days as well as drinking intensity per drinking occasion, modified the effect of alcohol intake on the risk of CHD. A Medline search for articles published between 1966 and 2006 was done using keywords related to disease (coronary heart disease, coronary death, myocardial infarction, ischemic heart disease), exposure (quantity or dose of alcohol intake and pattern of alcohol drinking) and frequency of alcohol drinking (regular, irregular, problem drinking, alcoholic intoxication, heavy episodic drinking, hangover). The final meta-analysis included six studies, four cohort studies and two case-control studies. Compared with those who abstained from alcohol, regular heavy drinkers had a reduced risk of CHD (RR 0.75; 95% CI: 0.64, 0.89) and heavy irregular or binge drinkers had an increased risk (RR 1.10; 95% CI: 1.03, 1.17). The dose-response relationship between the amount of alcohol consumed and CHD risk also differed between regular and irregular heavy drinkers (P<0.047). A J-shaped curve was seen for irregular drinkers: The nadir and the last protective dose of 28g per week (RR 0.59; 95% CI: 0.53 to 0.65) and 131g per week (RR 0.85; 95% CI: 0.72 to 0.99) were obtained included drinkers who consumed alcohol for two days a week or less. Conversely, in people who consumed alcohol for more than two days a week a significant protective effect was seen even when drinking high amounts of alcohol.
Cleophas, 1999 (neutral quality), a meta-analysis of 20 international studies, assessed the relationship between MI and consumption of different types of alcoholic beverages, both in low doses (one to four drinks per day) and high doses (more than four drinks per day). Eight cohort studies were included that reported on the association between alcohol consumption irrespective of the type of drink and cardiovascular death, as well as twelve prospective cohort studies that reported on the risk of MI and specific types of alcoholic drinks. Small doses of alcohol were associated with a reduced risk of mortality and CHD, while more than five drinks per day increased the risk of mortality; wine, beer and spirits were equally beneficial.
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Research Design and Implementation Rating Summary
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Bagnardi V, Zatonski W, Scotti L, La Veccha C, and Corrao G. (2008). Does drinking pattern modify the effect of alcohol on the risk of coronary heart disease?: Evidence from a meta-analysis. Journal of Epidemiology and Community Health, 2008 62 (7), 615-619.
Britton A, McKee M. The relation between alcohol and cardiovascular disease in Eastern Europe: Explaining the paradox. J Epidemiol Community Health. 2000 May; 54 (5): 328-332. Review.
Cleophas TJ. Wine, beer and spirits and the risk of myocardial infarction: a systematic review. Biomed Pharmacother. 1999;53(9):417-23.
Corrao G, Rubbiati L, Bagnardi V, Zambon A, Poikolainen, K. Alcohol and coronary heart disease: A meta-analysis. Addiction. 2000; 95: 1,505-1,523.
Di Castelnuovo A, Rotondo S, Iacoviello L, Donati MB, De Gaetano G. Meta-analysis of wine and beer consumption in relation to vascular risk. Circulation. 2002 Jun 18;105(24):2836-44.
Rimm EB, Williams P, Fosher K, Criqui M, Stampher MJ. Moderate alcohol intake and lower risk of coronary heart disease: meta-analysis of effects on lipids and haemostatic factors. BMJ. 1999; 319: 1523-1528.